LRCTC News - 2012
HPV Vaccine No 'License for Sex' in Girls
15 October 2012
There did not appear to be any difference in the sexual behaviors of adolescent girls who received the human papillomavirus (HPV) vaccine and their unvaccinated peers, researchers found.
Among girls ages 11 and 12 enrolled in a large, managed-care organization, there were no between-group differences in the rate of pregnancy, testing for or diagnosis of a sexually transmitted infection, or receipt of contraceptive counseling by a physician, according to Robert Bednarczyk, PhD, of Kaiser Permanente Center for Health Research-Southeast in Atlanta, and colleagues.
In addition, the average age at the first composite outcome was no different between vaccinated and unvaccinated girls (14.4 versus 14.6, P=0.325), which indicates "that there may not be any earlier onset of sexual activity after HPV vaccination," the researchers reported online in Pediatrics.
"It is likely that any disinhibition or risk compensation would occur closer to the time of vaccination (i.e., within 18 months) rather than much later," they wrote. "If HPV vaccination was 'a license for sex,' we would have expected to see more adverse outcomes shortly after vaccination, when the girls were more aware of their recent vaccination status."
The Advisory Committee on Immunization practices recommended in 2006 that all girls ages 11 to 12 receive the HPV vaccine, with the idea that immunity to the sexually transmitted disease will develop before sexual activity begins.
Uptake of the vaccine, however, has trailed that of other recommended adolescent vaccines, including tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine and the quadrivalent meningococcal conjugate vaccine (MCV4).
One concern raised about HPV vaccination is that immunized girls will increase their sexual activity because of less fear of disease. Surveys based on self-reported data have shown that girls do not plan on changing their sexual behaviors after vaccination, but no studies had examined the issue using clinical outcomes free from the bias of self-report.
Bednarczyk and colleagues did such a study using electronic data from Kaiser Permanente Georgia. Their analysis included 1,398 girls ages 11 or 12 who were enrolled in the health plan from July 2006 through December 2007 -- 35% received at least one dose of HPV vaccine in addition to other vaccines and the rest received Tdap, MCV4, or both, but not HPV vaccine.
Through 3 years of follow-up, the rate of pregnancy, testing for or diagnosis of a sexually transmitted infection, and receipt of contraceptive counseling was 5.5 per 100 person-years in the vaccinated group and 3.9 per 100 person-years in the control group, a difference that was not statistically significant after adjustment for healthcare-seeking behavior, age at vaccination, race, and socioeconomic status (incidence rate ratio 1.29, 95% CI 0.92 to 1.80).
There were no between-group differences in rates of secondary outcomes either, although the rate of receiving contraceptive counseling came close to being higher in the vaccinated group (1.39 versus 0.50 per 100 person-years; IRR 2.31, 95% CI 0.99 to 5.38).
"The administrative data used for this study did not provide an opportunity to do a detailed examination of the reasons for this counseling or of the extent of hormonal contraceptive use among girls in this cohort," the authors wrote.
They acknowledged some additional limitations, including the possibility that differences remain between the vaccinated and unvaccinated girls despite adjustment for some confounders, the use of administrative data, the possibility that some of the girls received vaccines or reproductive healthcare at outside clinics, the limited ability to generalize the findings to other age groups, and possible confounding by physician behavior.
Primary source: Pediatrics
Source reference:
Bednarczyk R, et al "Sexual activity-related outcomes after human papillomavirus vaccination" Pediatrics 2012; DOI: 10.1542/peds.2012-1516.
Cervical cancer and pre-cancer cervical growths require single HPV protein
26 September 2012
Researchers at the University of Wisconsin-Madison have found that a single HPV protein is required for cervical cancer and even pre-cancer growths in the cervix to survive.
In anticipation of a clinical trial in humans, the scientists and their collaborators are moving quickly to test if a gene-silencing technique could cripple the protein and eliminate cervical cancer and pre-cancerous growths in specially-bred mice.
The study, appearing online in Cancer Research, is the first to show that the protein works in living animals and in pre-cancerous growths as well as full-blown cervical cancer.
Cervical cancer is relatively rare in the United States, thanks to the widespread use of Pap smears as a screening tool. But pre-cancer lesions in the cervix, called cervical inter-epithelial neoplasias, or CINs, are common.
Low-grade CINs are typically left alone because most will shrink and pose no problem. But women with high-grade CINs have a 10 percent chance of getting cervical cancer, says Dr. Paul Lambert, senior author on the paper. In addition, surgical treatment of high-grade CINs carries a risk of excessive bleeding and even infertility.
Scientists know that two HPV cancer-causing proteins, or oncoproteins—E6 and E7—are always expressed in cervical cancer. Lambert and his team at UW's McArdle Laboratory of Cancer Research conducted experiments in cultured cell lines that suggested that the oncoproteins caused cervical cancer as well as anal and head and neck cancers. The researchers also learned that E7 had a much greater ability than E6 to cause cancer.
Other studies in different types of cancers suggested that when oncoproteins were involved, they needed to work together—blocking the expression of both often led to a more effective reduction of tumors than blocking either one alone.
But Lambert, a member of the UW Carbone Cancer Center, was intrigued with E7's power.
"In thinking of treatments, we wondered in this case if we could target just one oncoprotein, the most potent one, rather than two, which could be much more complicated," he says.
Dr. Sean Jabbar and Soyeong Park in the Lambert laboratory created and bred mice in which they could control the expression of both E7 and E6. They found that when he turned off E7 but left E6 on, the cervical cancers and CINs melted away.
"This told us that E7 should be an excellent therapeutic target for HPV-associated cancers, including pre-cancerous CINs," Lambert says.
If the gene-silencing experiments that are expected to take place soon prove effective, there's a good chance that the blocking approach could be used to control the disease without surgery.
Women in developing countries might benefit greatly, Lambert adds.
"Cervical cancer is prevalent around the world in places where screening does not exist and surgery is not available," he says.
17th September 2012 Journal : Cancer
Rating HPV biomarkers in head, neck cancers: Combinations work better than viral DNA in tumors alone
26 September 2012
A new study finds that while one popular biomarker for HPV is not a reliable predictor of mortality from the cancers alone, combinations of some biomarkers showed much more promise
Not all head and neck cancers are created equal. Those started by infection with the human papillomavirus are less often fatal than those with other causes, such as smoking. Detection of a reliable fingerprint for HPV could help patients avoid unnecessarily harsh treatment. A new study finds that while one popular biomarker for HPV is not a reliable predictor of mortality from the cancers alone, combinations of some biomarkers showed much more promise.
"Everybody who has studied it has shown that people with virally associated disease do better," said Karl Kelsey, aprofessor of epidemiology and pathology and laboratory medicine at Brown University, and corresponding author of the study in Cancer Research. "There are now clinical trials underway to determine if they should be treated differently. The problem is that you need to appropriately diagnose virally related disease, and our data suggests that people need to take a close look at that."
In the study, Kelsey and his multi-institutional team of co-authors measured the ability of a variety of biomarkers to predict mortality from head and neck squamous cell carcinoma (HNSCC). Their data came from hundreds of adult head and neck cancer patients in the Boston area that they have been tracking since late 1999. As part of that data set, they were able to look at blood serology and tumor tissue samples, and they interviewed participants about risk behaviors such as smoking and drinking.
DNA alone not reliable
One of the most important findings of the study, Kelsey said, is that extracting and amplifying the DNA of HPV in tumors, a popular notion among doctors given its success in confirming HPV's role in cervical cancers, is not particularly helpful in predicting eventual mortality from head and neck cancer.
For example, among 94 patients for whom the researchers could assess the predictive value of all the biomarkers in the study, HPV DNA was present in tumors of 59 patients and absent in 35. Among the 59 who had the DNA, 23 of them, or 39 percent, had died. Among the 35 without the DNA, 13 of them, or 37 percent had died.
"You can't just do PCR [a DNA amplification technique] of the virus in the tumor and assume it means much," Kelsey said.
More promising combinations
Among several other potential HPV biomarkers in patients, the most reliable predictors of mortality turned out to be certain combinations of them, particularly antibodies to the E6 and E7 proteins that are expressed by the virus and have the effect of turning off cells' ability to suppress tumors.
Kelsey and his colleagues found that measuring blood serum levels of antibodies that respond to E6 and E7 helped to assign meaning to measures of HPV DNA in tumors. Among people who had both HPV DNA and E6/E7 measurements, those with HPV DNA in tumors who were E6/E7 negative died in 30 of 56 cases, while those with HPV DNA in tumors who were E6/E7 positive died in only eight of 55 cases.
Levels of E6 and E7 antibodies in blood also proved telling in combination with staining tumors to detect the p16 protein, which indicates that tumor-suppression has been inactivated. Among patients in whom both those tests were both run, those with p16 overexpression who were E6/E7 negative had a much higher rate of death (11 in 17 cases) than people who did not overexpress p16 and were E6/E7 positive (3 in 9 cases) or those who overexpressed p16 and who were also E6/E7 positive (6 in 37 cases).
"Our study strongly suggests that the combination of detection of HPV 16 DNA in HNSCC tumors or p16 immunostaining with E6/E7 antibodies represents the most clinically valuable surrogate markers for the identification of patients with HNSCC who have a better prognosis," Kelsey and his co-authors concluded.
In a companion paper published simultaneously in Cancer Research another team found that measuring viral load and patterns of viral gene expression were also useful markers.
September 18th 2012 Journal: Cancer Research
Biomarkers of HPV in Head and Neck Squamous Cell Carcinoma
19 September 2012
The presence or absence of human papillomavirus DNA on its own in an individual's head or neck cancer does not provide enough information to help predict a patient's survival, according to a pair of new papers in the journal Cancer Research.
Two research teams — headed by investigators at Brown University and Heidelberg University, respectively — looked at the reliability of using PCR-based HPV testing to determine which head and neck squamous cell carcinomas were HPV-related and, thus, more apt to respond to treatment.
Previous studies have shown that individuals with HPV-associated head and neck cancers tend to have more favorable outcomes than individuals whose head and neck cancers that are not related to HPV infection.
"Everybody who has studied it has shown that people with virally associated disease do better," Brown University pathology researcher Karl Kelsey, a senior author on one of the new studies, explained in a statement.
"There are now clinical trials underway to determine if they should be treated differently," he added. "The problem is that you need to appropriately diagnose virally related disease, and our data suggests that people need to take a close look at that."
For their part, Kelsey and his co-authors from the US and Germany assessed the utility of testing for the presence of HPV by various means in individuals with head and neck cancer. This included PCR-based tests for HPV DNA in the tumor itself, tests aimed at detecting infection-associated antibodies in an individual's blood, and tests for elevated levels of an HPV-related tumor suppressor protein.
For 488 individuals with HNSCC, researchers did blood-based testing for antibodies targeting HPV16 in general, as well as testing for antibodies that target the viral proteins E6 and E7.
For a subset of patients, the team assessed the tumors themselves for the presence of HPV DNA and/or for elevated levels of the host tumor suppressor protein p16.
Based on patterns in the samples, the group determined that the presence of viral E6 and E7 proteins in the blood was linked to increased survival for individuals with an oropharyngeal form of HNSCC, which affects part of the throat known as the oropharynx.
A positive test for HPV DNA alone was not significantly linked to head and neck cancer outcomes. On the other hand, when found in combination with E6 and E7 expression, a positive HPV16 test did coincide with improved oropharyngeal cancer outcomes.
Likewise, elevated levels of p16 in a tumor were not especially informative on their own, though they did correspond to better oropharyngeal cancer survival when found together with positive blood tests for E6 and E7.
Based on these findings, Kelsey and his team concluded that "[a] stronger association of HPV presence with prognosis (assessed by all-cause survival) is observed when 'HPV-associated' HNSCC is defined using tumor status (HPV DNA or P16) and HPV E6/E7 serology in combination rather [than] using tumor HPV status alone."
In a second study, meanwhile, a German group that focused on the oropharyngeal form of the disease found its own evidence arguing against the use of HPV DNA as a solo marker for HPV-associated head and neck cancer.
For that analysis, researchers assessed 199 fresh-frozen oropharyngeal squamous cell carcinoma samples, testing the tumors for HPV DNA and p16. They also considered the viral load in the tumors and looked for gene expression profiles resembling those described in cervical carcinoma — another cancer associated with HPV infection.
Again, the presence of HPV DNA appeared to be a poor indicator of HPV-associated cancers or predictor of cancer outcomes. Whereas nearly half of the tumors tested positive for HPV16 DNA, just 16 percent and 20 percent had high viral loads and cervical cancer-like expression profiles, respectively.
The researchers found that a subset of HPV DNA-positive tumors with high viral load or HPV-associated expression patterns belonged to individuals with better outcomes. In particular, they found that cervical cancer-like expression profiles in oropharyngeal tumors coincided with the most favorable outcomes, while high viral load in the tumors came a close second.
"We showed that high viral load and a cancer-specific pattern of viral gene expression are most suited to identify patients with HPV-driven tumors among patients with oropharyngeal cancer," Dana Holzinger, that study's corresponding author, said in a statement.
"Once standardized assays for these markers, applicable in routine clinical laboratories, are established, they will allow precise identification of patients with oropharyngeal cancer with or without HPV-driven cancers and, thus, will influence prognosis and potentially treatment decisions," added Holzinger, who is affiliated with the German Cancer Research Center and Heidelberg University.
In a commentary article online today in Cancer Research, Eduardo Méndez, a head and neck surgery specialist with the University of Washington and Fred Hutchinson Cancer Research Center, discussed the significance of the two studies and their potential impact on oropharyngeal squamous cell carcinoma prognoses and treatment.
But he also cautioned that more research is needed to understand whether the patterns described in the new studies hold in other populations and to tease apart the prognostic importance of HPV infection in relation to additional prognostic markers.
Pub: Cancer Research September 2012
Author: Caihua Liang et al
Quest Launches TERC MDx to Identify Women at High Risk of Cervical Cancer after Uncertain Pap Test
17 September 2012
Quest Diagnostics last month launched a molecular diagnostic for women who have received unclear reports about their risk of cervical cancer after being tested on standard Pap smears or HPV tests.
The company plans to market the Cervical Cancer TERC test to physicians as a tool that they can use in conjunction with Pap smears and HPV tests to gain more insights into a woman's risk of cervical cancer. The test analyzes the human telomerase RNA component, or TERC, gene marker, for which Quest holds a non-exclusive license from the National Institutes of Health. The test operates on a fluorescence in situ hybridization-based platform and analyzes residual samples from Pap smears.
"The TERC test acts like a ‘second opinion’ when results from conventional screening are unclear," Daniel Jones, medical director of cancer diagnostics services at Quest, told PGx Reporter over e-mail.
A Pap, short for Papanicolaou, gauges a woman's risk of cervical cancer by analyzing changes in cervical cells. A human papillomavirus test detects the sexually transmitted disease and can also identify viral types that place women at high risk for cervical cancer. The TERC test, meanwhile, detects whether a woman carries extra copies of the chromosome arm 3q and harbors amplified TERC genes, which researchers from the NIH and elsewhere have shown in clinical trials to be associated with abnormal cellular changes in the cervix that progress to cancer.
In a study published in the American Journal of Pathology in 2005, researchers led by Kerstin Heselmeyer-Haddad of the National Cancer Institute analyzed 59 previously stained Pap smears with a FISH probe, and reported that patients who had mild-to-moderate growth of abnormal squamous cells in the cervix and progressed to a severe state of cervical cancer displayed a 3q gain.
Data from the study "suggest that 3q gain is required for the transition from cervical intraepithelial neoplasia 1/2 [the mild-to-moderate state] to CIN3 [the severe state] and that it predicts progression," Heselmeyer-Haddad et al. reported. "Of note, 3q gain was found in 33 percent of cytologically normal Pap smears from women who were diagnosed with CIN3 or invasive cervical carcinoma after a short latency."
According to the study authors, the sensitivity of the molecular diagnostic in assessing the progression from CIN1/CIN2 to CIN3 was 100 percent. The specificity of predicting regression or which patients would not progress to severe cervical dysplasia or cancer, however, was 70 percent. "We conclude that the detection of 3q gain and amplification of TERC in routinely collected Pap smears can assist in identifying low-grade lesions with a high progression risk and in decreasing false-negative cytological screenings," Heselmeyer-Haddad et al. concluded.
Quest believes that doctors should use the TERC test for women with abnormal test results by Pap and HPV to identify women who are at high risk or low risk for cervical cancer. By doing this, physicians may be able to recommend additional cervical biopsies and monitoring for women at high risk of the disease, while ruling out the need for such procedures for low-risk women.
The company estimates that as many as 1.5 million women in the US receive a Pap test revealing mild cellular abnormalities. This diagnosis and subsequent treatment "is associated with higher patient anxiety, morbidity and cost, although many cases never progress to cancer," Quest said in a statement.
The TERC test is being launched after the US Preventative Services Task Force and several professional societies this year revised cervical cancer screening guidelines. Instead of annual checkups for cervical cancer, the treatment guidelines now recommend that doctors administer Pap smears every three years for women 21 to 65 years old, or a combination of Pap and HVP testing every five years for women 30 to 65 years old.
These revisions are attributable to the reduction in cervical cancer mortality rates since 1940, when the disease was a major cause of death for US women of childbearing age. In 2010, approximately 4,200 women died of cervical cancer out of an estimated 12,200 women diagnosed with the disease.
However, because doctors are now being advised in treatment guidelines to screen women less frequently, Quest believes that it's even more important to employ more accurate tools to identify women at the highest risk for developing cervical cancer. "Guidelines represent the bare minimum of required clinical practice. We believe each clinician should consider the guidelines to gauge appropriate clinical practice, but ultimately use her or his clinical discretion to manage the individual patient," Jones said. "New guidelines recommending less frequent screening mean testing must be highly reliable to reduce the possibility that at-risk women are missed between screens."
Of course if treatment guidelines were to specifically recommend TERC testing in addition to Pap and HPV tests for unclear cases, Quest would have a much easier time getting doctors to adopt this additional procedure in their practices. Following the launch of the TERC test, Quest is planning to educate physicians, payors, and medical groups about the molecular diagnostic. Additionally, "we intend to engage a dialog regarding consideration of inclusion of genomic testing, including TERC, in future guidelines," Jones noted.
According to Quest, the Medicare national limitation amount for the test is $146.
By Turna Ray 12th September 2012 Genomeweb.com Pharmacogemics Reporter
Frequency and risk factors for prevalent, incident, and persistent genital carcinogenic human papillomavirus infection in sexually active women: community based cohort study
29 June 2012
To investigate frequency and risk factors for prevalent, incident, and persistent carcinogenic human papillomavirus (HPV) in young women before the introduction of immunisation against HPV types 16 and 18 for schoolgirls.
Participants 2185 sexually active female students, mean age 21 years (range 16-27), 38% from ethnic minorities, who took part in the POPI (prevention of pelvic infection) chlamydia screening trial in 2004-08 and who provided duplicate, self taken vaginal swabs and completed questionnaires at baseline. At follow-up, a median of 16 months later, 821 women (38%) returned repeat vaginal swabs by post. In 2009-10, stored samples were tested for HPV.
Results Samples from 404/2185 (18.5% (95% CI 16.9% to 20.2%)) of the cohort were positive for carcinogenic HPV at baseline, including 15.0% (327) positive for non-vaccine carcinogenic genotypes. Reporting two or more sexual partners in the previous year and concurrent Chlamydia trachomatis or bacterial vaginosis were independent risk factors for prevalent vaginal HPV infection. Infection with one or more new HPV types was found in 17.7% (145/821) of follow-up samples, giving an estimated annual incidence of carcinogenic HPV infection of 12.9% (95% CI 11.0% to 15.0%). Incident infection was more common in women reporting two or more partners in the previous year, aged<20, of black ethnicity, or with C trachomatis vaginosis at baseline. Multiple partners was the only independent risk factor for incident infection (adjusted relative risk 1.99 (95% CI 1.46 to 2.72)). Of 143 women with baseline carcinogenic HPV infection, 20 (14% (8.3% to 19.7%) had infection with the same carcinogenic HPV type(s) detected after 12-28 months. Of these women, 13 (65%) had redetected infection with HPV 16 or 18, and nine (45%) with non-vaccine carcinogenic HPV genotypes.
Conclusion In the first UK cohort study of carcinogenic HPV in young women in the community, multiple sexual partners was an independent predictor of both prevalent and incident infection. Infection with non-vaccine carcinogenic genotypes was common. Although current HPV vaccines offer partial cross protection against some non-vaccine carcinogenic HPV types, immunised women will still need cervical screening.
BMJ 2012; 344 doi: 10.1136/bmj.e4168 (Published 22 June 2012)
- Pippa Oakeshott, reader in general practice1,
- Adamma Aghaizu, scientist epidemiology1,
- Fiona Reid, senior lecturer in medical statistics1,
- Rebecca Howell-Jones, scientist epidemiology2,
- Phillip E Hay, reader in genitourinary medicine3,
- S Tariq Sadiq, reader in sexual health/HIV medicine3,
- Charles J Lacey, professor of genitourinary medicine4,
- Simon Beddows, microbiologist5,
- Kate Soldan, epidemiologist2
A discrete population of squamocolumnar junction cells implicated in the pathogenesis of cervical cancer
15 June 2012
In this study, we uncovered a discrete population of SC junctional cells with unique morphology and gene-expression profile
A new studypublished in PNAS may have the answer to the mystery of how a common medical procedure in the 1920s served to keep the rates of cervical cancer down,, says AFP's Kerry Sheridan. In the study, researchers identified a population of stem-like cells that are responsible for most cases of cervical cancer when they are infected with human papillomavirus, Sheridan reports. In the 1920s, it was routine for doctors to cauterize the cervix after a woman gave birth, which burned off abnormal cells and lowered the cervical cancer rate. "Back then, they noted that women who underwent the procedure almost never developed cervical cancer, but they were not sure why," she adds. "Now, doctors believe it was because they were burning off a population of host cells that cannot regenerate." The cells, located at the opening of the cervix at the squamo-columnar junction, appear to be remnants of embryogenesis, the researchers write.
The findings are now causing some clinicians to consider whether the cauterization procedure — or a similar one that freezes the cells instead of burning them off — should be revived, especially in the developing world where cervical cancer rates remain high, Sheridan says. The researchers who conducted the study are also hoping that further study will also show whether these stem-like cells are also associated with other HPV cancers.
Scientific paper:
Infection by carcinogenic human papillomaviruses (HPV) results in precancers [cervical intraepithelial neoplasia (CIN)] and cancers near the ectoendocervical squamocolumnar (SC) junction of the cervix. However, the specific cells targeted by HPV have not been identified and the cellular origin of cervical cancer remains elusive. In this study, we uncovered a discrete population of SC junctional cells with unique morphology and gene-expression profile. We also demonstrated that the selected junctional biomarkers were expressed by a high percentage of high-grade CIN and cervical cancers associated with carcinogenic HPVs but rarely in ectocervical/transformation zone CINs or those associated with noncarcinogenic HPVs. That the original SC junction immunophenotype was not regenerated at new SC junctions following excision, not induced by expression of viral oncoproteins in foreskin keratinocytes, and not seen in HPV-related precursors of the vagina, vulva, and penis further support the notion that junctional cells are the source of cervical cancer. Taken together, our findings suggest that carcinogenic HPV-related CINs and cervical cancers are linked to a small, discrete cell population that localizes to the SC junction of the cervix, expresses a unique gene expression signature, and is not regenerated after excision. The findings in this study uncover a potential target for cervical cancer prevention, provide insight into the risk assessment of cervical lesions, and establish a model for elucidating the pathway to cervical cancer following carcinogenic HPV infection.
A discrete population of squamocolumnar junction cells implicated in the pathogenesis of cervical cancer Michael Herfs et al National Academy of Sciences PNAS June 2012
Groundbreaking Discovery of the Cellular Origin of Cervical Cancer
14 June 2012
A team of scientists from A*STAR’s Institute of Medical Biology (IMB) and Genome Institute of Singapore (GIS) together with clinicians from Boston’s Brigham and Women’s Hospital (BWH) have identified a unique set of cells in the cervix that are the cause of human papillomaviruses (HPV) related cervical cancers.
Significantly, the team also showed that these cells do not regenerate when excised. These findings have immense clinical implications in the diagnosis, prevention and treatment of cervical cancer. The study was published in the prestigious journal, Proceedings of the National Academy of Sciences (PNAS), this week
Dr Christopher P. Crum, Director of Women’s and Perinatal Pathology in the Department of pathology at BWH, said, “It has been a decades-old mystery why cervical cancers caused by HPV arise only from a discrete region of the cervix, known as the ‘squamocolumnar junction’, despite the presence of the virus throughout the genital tract. The discovery of these cells finally resolves this mystery and will have wide-ranging impact from developing more meaningful animal models of early cervical carcinogenesis to clinical implications.”
The team discovered that this discrete set of cells, located at the squamocolumnar junction of the cervix, uniquely express biomarkers that are seen in all forms of invasive cervical cancers linked to HPV. This means that the signature markers of this population of cells can provide a way of distinguishing potentially dangerous precancerous lesions from those with a benign prognosis.
Dr Wa Xian, Principal Investigator at IMB, said, “Our study also revealed that this exotic population of cells does not reappear after ablation by cone biopsy. This finding helps to explain the low rate of new HPV infections in the cervix after excisional therapy and also raises the distinct possibility that preemptive removal of these cells in young women could reduce their risk of cervical cancer. This could be an alternative to current vaccines which only protect against HPV 16 and 18.”
This study further validates previous work by Dr Xian and Dr McKeon in collaboration with BWH and NUS, which showed for the first time that some cancers originate from just a small set of cells that are unique from the other cells that reside around them. (Refer to Background)
7. Dr Frank Mckeon, Senior Group Leader at GIS, said, “Our previous work on esophageal cancer opened up the possibility of ‘preventive therapy’ to stamp out the disease by eliminating this small group of cells. This recent work in the cervix further validates this concept and raises important possibilities for early intervention to prevent malignancies linked to very small populations of these unusual, discrete population of cells.”
Prof Birgitte Lane, Executive Director of IMB, said, ““This compelling study lends further weight to the importance of specific target cell populations underlying cancer. It is a powerful example of what can be done by combining skilled pathology with modern molecular genetics to uncover important new information, even in such a well-studied disease as cervical cancer.”
Tuesday 12th June 2012 Agency for Science,Technology & Research, Singapore
New technique detects cancer cells with sound
11 May 2012
Using lasers and sound, the researchers are able to create much higher-quality images of body parts.
A new imaging technology called photo-acoustic tomography is being developed by researchers at Washington University in St. Louis, Reuters reports in a video. Using lasers and sound, the researchers are able to create much higher-quality images of body parts than they currently can.
"It's actually a way of using sound to detect optical features," researcher Lihong Wong tells Reuters. "Instead of looking at optical structures, we're listening to optical structures. Light is beamed at the body and absorbed by the tissues. It then scatters, and causes a rapid increase in temperature, which then produces sound waves, Reuters reports. Researchers then detect these sound waves, and create an optical image of the tissues and organs. Wong adds that this technology will give doctors a detailed look at what's happening in the body in real time. The hope, Reuters adds, is that they can use this method to detect early signs of cancer before it develops into a tumor, especially in tissues and organs that aren't easily imaged by conventional means.
Scientific American May 5,2012 New technique detects cancer cells with sound
Global burden of cancers attributable to infections in 2008: a review and synthetic analysis
11 May 2012
Infections with certain viruses, bacteria, and parasites have been identified as strong risk factors for specific cancers.
Background
Methods
Findings
Interpretation
Funding
Invaders from Another Cell Line
27 April 2012
Retractions of scientific papers are usually awkward, and sometimes involve investigations, firings, or scandal
In the case of Robert Mandic, a researcher at the University Hospital Giessen and Marburg in Germany, the retraction of an article he wrote for Oral Oncology didn't involve fraud or malfeasance, but "it wasn't pleasant," he tells The Wall Street Journal's Amy Dockser Marcus. Mandic's experiments and subsequent paper had been about head and neck cancer, but after the work was published, he realized that the cell lines he'd worked with had actually been cervical cancer lines. "Dr. Mandic entered a largely secret fellowship of scientists whose work has been undermined by the contamination and misidentification of cancer cell lines used in research labs around the world," Marcus writes. "Cancer experts seeking to solve the problem have found that a fifth to a third or more of cancer cell lines tested were mistakenly identified — with researchers unwittingly studying the wrong cancers, slowing progress toward new treatments and wasting precious time and money."
There have been hundreds such documented cases caused either by mislabeling, carelessness, or other mistakes, she adds. One of the biggest problems is also one of the most famous — aggressive cervical cancer cells taken from Henrietta Lacks in 1951, and used for decades in labs all over the country, have been known to take over other cancer cell lines, sometimes without researchers knowing, Marcus says. Further, cell lines repositories in the US, UK, Japan, and Germany have estimated that anywhere between 18 percent and 36 percent of cancer cell lines are mislabeled.
"The National Institutes of Health have, so far, not required cell line authentication as a condition of receiving federal grants," Marcus says. "One challenge is getting scientists to acknowledge their cell line is contaminated. The prevailing attitude, according to researchers, is that the other lab's cell line may be contaminated but not mine
Oral Oncology ; Robert Mandic, University Hospital Giessen and Marburg, Germany
The Wall Street Journal; Amy Dockser Marcus. 23rd April 2012
Target set on cancer gene MCL1
20 April 2012
A research team pursuing one of the most commonly altered genes in cancer has laid a critical foundation for understanding this gene that could point the way toward developing drugs against it.
The study highlights several compounds that repress MCL1. In addition, the Broad says, the study reports a companion gene, BCL-xL, that can help predict whether a specific tumor is dependent on MCL1 for its survival. "It was not immediately obvious that MCL1 was such an attractive therapeutic target in cancer," says the Broad's Todd Golub. "But once it became clear that MCL1 was something that we wanted to turn off in tumor cells, we faced two additional problems: we didn't know which tumors depend on it for survival and there wasn't an obvious path to drug discovery. This paper addresses those two challenges."
The researchers started by suppressing MCL1 in several cancer cell lines to determine which ones were dependent on the gene. They then looked for a marker that could predict which cell lines were dependent, and found that BCL-xL was the clearest indicator, the Broad says. The team also tested about 3,000 compounds to search for ones that turned off MLC1 in cancer cells, and found some that could serve as a starting point towards developing a drug specifically to target MCL1.
Cancer Cell - April 2012
Todd Golub, director of the Broad’s Cancer Program
Charles A. Dana Investigator in Human Cancer Genetics at the Dana-Farber Cancer Institute.
High Throughput for HPV
05 April 2012
Sensitive and specific detection of human papillomaviruses (HPV) in cervical samples is a useful tool for the early diagnosis of epithelial neoplasia and anogenital lesions.
Researchers from the University of Helsinki have developed a DNA microarray-based test to detect and genotype 15 high-risk and two low-risk human papillomavirus types, as they report in PLoS One. "The method is based on multiplex PCR amplification of the viral L1 region using an improved set of type-specific PGMY primers and subsequent ligation detection reaction. Further, we establish an objective criterion for HPV type presence by statistical comparison to a background distribution," the researchers say. They add that their preliminary results indicate that their test could be used in the clinic. "In [the] future, HPV genotyping is likely to be launched to clinical use for the management and follow-up of patients with cervical epithelial abnormalities requiring accurate and economical high-throughput testing," the Helsinki team adds.
Recent studies support the feasibility of HPV DNA testing instead of cytology (Pap smear) as a primary test in population screening for cervical cancer. This is likely to be an option in the near future in many countries, and it would increase the efficiency of screening for cervical abnormalities. We present here a microarray test for the detection and typing of 15 most important high-risk HPV types and two low risk types. The method is based on type specific multiplex PCR amplification of the L1 viral genomic region followed by ligation detection reaction where two specific ssDNA probes, one containing a fluorescent label and the other a flanking ZipCode sequence, are joined by enzymatic ligation in the presence of the correct HPV PCR product. Human beta-globin is amplified in the same reaction to control for sample quality and adequacy. The genotyping capacity of our approach was evaluated against Linear Array test using cervical samples collected in transport medium. Altogether 14 out of 15 valid samples (93%) gave concordant results between our test and Linear Array. One sample was HPV56 positive in our test and high-risk positive in Hybrid Capture 2 but remained negative in Linear Array. The preliminary results suggest that our test has accurate multiple HPV genotyping capability with the additional advantages of generic detection format, and potential for high-throughput screening.
Jarmo Ritari et al Institute of Biotechnology, University of Helsinki, Helsinki, Finland, PLoS One 30 March 2012
p16INK4a and p14ARF mRNA expression in Pap smears is age-related
02 April 2012
In Modern Pathology, researchers from Charité-Universitätsmedizin in Berlin report that expression of p16INK4a and p14ARF mRNA in Pap smears is related to age
Expression of high-risk HPV oncogenes results in a strong overexpression of cellular protein p16INK4a. Immunohistochemical staining for p16INK4a is widely used as diagnostic marker. However, p16INK4a upregulation was also described as a biomarker of age. Here we analyzed p16INK4a expression in cervical smears to investigate if patient age may influence p16INK4a-based cervical cancer diagnosis. p14ARF was analyzed as a related supportive biomarker. Cervical scrapes were taken and stored in RNAlater. Total RNA was extracted, and cDNA was analyzed for expression of p16INK4a and p14ARF relative to β-actin, by real-time reverse transcriptase PCR SYBR-Green I assays. Patient-derived smears referred as HSIL (n=45) had 6.27-fold higher p16INK4a mRNA expression than smears of cytologically normal and HPV-negative persons (n=48). Expression of p14ARF was 4.87-fold higher. When women with normal diagnoses were stratified for age, a significantly enhanced p16INK4a (2.88-fold) and p14ARF (1.9-fold) expression was observed as a consequence of ageing. A significant age-dependent upregulation was also observed in older HSIL patients (2.54-fold). Our study revealed significantly enhanced expression of p16INK4a/p14ARF mRNA in cervical scrapes referred to as HSIL compared with normal women. An age-dependent bias has to be considered when quantifying these tumor suppressor genes, with respect to cervical cancer development.
Authors:
, , , and
Modern Pathology 25, 465-470 (March 2012) | doi:10.1038/modpathol.2011.179
Viruses Recruited as Killers of Tumors
02 April 2012
Viruses can be designed to attack tumors.
In 1951, a 4-year-old boy with leukemia contracted chickenpox. His liver and spleen, swollen by the cancer, soon returned to normal, and his elevated blood cell count fell to that of a healthy child.
His doctors at the Laboratory of Experimental Oncology in San Francisco were thrilled by his sudden remission, but the blessing was short-lived. After one month, his leukemia returned and progressed rapidly until the child’s death.
In the early 1900s, not much could be done for cancer patients. Unless surgeons could excise a tumor, the disease typically spelled a swift and inevitable end. But in dozens of published cases over the years, doctors noticed a peculiar trend: Struggling cancer patients sometimes enjoyed a brief reprieve from their malignancies when they caught a viral infection.
It was not a coincidence. Common viruses sometimes attack tumor cells, researchers discovered. For decades, they tried to harness this phenomenon, to transform it into a cancer treatment. Now, after a long string of failures, they are nearing success with viruses engineered to kill cancer.
“It’s a very exciting time,” said Dr. Robert Martuza, chief neurosurgeon at the Massachusetts General Hospital and professor of neuroscience at Harvard Medical School. “I think it will work out in some tumor, with some virus.” Candidates are already in advanced trials, he noted.
Cancer cells are able to replicate wildly, but there’s a trade-off: They cannot ward off infection as effectively as healthy cells. So scientists have been looking for ways to create viruses that are too weak to damage healthy cells yet strong enough to invade and destroy tumor cells. It has been a long, difficult challenge.
Researchers started down this road in 1904, when they discovered that women with cervical cancer temporarily recovered when given a rabies vaccination. By midcentury, physicians were administering live viruses to cancer patients. They tried infecting terminally ill children with polio and adenovirus. They injected patients with concoctions from the feces of normal children, from sick chickens, and from “feline spleen suspension” of rural kittens infected with “cat plague.”
These experiments proved ill fated. The cancer returned, or — in the worst cases — the injections themselves caused “the development of lethal infection in the host,” according to a 1964 American Journal of Pathology report.
The field was abandoned for a time. But in 1991, Dr. Martuza seized upon the idea of using the herpes simplex virus (HSV-1) as a cancer-fighter.
The genome of HSV-1 is comparatively large and can accommodate a number of mutations and deletions. Dr. Martuza weakened the virus by removing some of its genes. The modified virus was injected into mice with brain cancer, and it did bring about remission. But most of the mice died of encephalitis.
In 1990, Bernard Roizman, a virologist at the University of Chicago, found a “master gene” in the herpes virus. When this gene is removed, the virus no longer has the strength to overcome healthy cells’ defenses. As it turned out, the modified virus was so crippled that it could only slow tumor growth.
Then, in 1996, Dr. Ian Mohr, a virologist at New York University, stumbled on a way of further altering Dr. Roizman’s crippled virus. He exposed it repeatedly to cancer cells until a new viral mutant evolved with the ability to replicate in those cells.
Dr. Mohr and a doctoral student, Matt Mulvey, then engineered a way for their virus to evade the immune system, making it an even more potent cancer-killing agent.
Unlike chemotherapy, which can diminish in effectiveness over time, oncolytic viruses multiply in the body and gain strength as the infection becomes established. In addition to attacking cancer cells directly, some also produce an immune response that targets tumors.
Today, several potential cancer-fighting viruses are in trials, including two in Phase 3 trials.
An engineered form of vaccinia — the viral agent that helped eradicate smallpox — is being tested against advanced liver cancer, the third leading cause of cancer deaths globally. In a recent trial, survival for patients treated with high doses of the virus, called JX-594, doubled to 14 months from 7, compared with that of patients treated with low doses.
“To see that kind of response in a randomized trial is simply unheard of,” said Tony Reid, the director of clinical investigation at the Moores Cancer Center of the University of California, San Diego, who has no financial ties to the virus’s manufacturer.
A herpes virus based on Dr. Mohr’s original discovery is in advanced trials against melanoma; initial data showed a 26 percent response rate in patient regression and survival. A reovirus is being tested against head and neck cancers, often difficult to treat.
According to the researchers, the side effects of treatment with these viruses are minimal, and include nausea, fatigue and aches. “In comparison to what happens with standard chemotherapy, flulike symptoms are very manageable,” said Dr. Reid, who has treated hundreds of patients with oncolytic viruses.
Oncolytic viruses are likely to find a place in medicine, especially paired with other therapies targeting difficult and aggressive tumors, said Gary Hayward, a virologist at the Johns Hopkins Herpesvirus Research Program. But the “biology is complex,” Dr. Hayward warned, and progress is likely to be incremental.
Dr. Mulvey now heads a firm in Baltimore testing viruses to fight melanoma and bladder cancer. The biggest challenge now, he said, is simply convincing others that the new treatment is “not science fiction.”
New York Times -
Published: March 19, 2012
By RACHEL NUWER
Pan-London HPV Implementation Meeting
09 March 2012
The first pan-london HPV Implementation meeting was held on Firday 9th March at Northwick Park Hospital.
The presentation is now available to view through the following link.
Screening and cervical cancer cure: population based cohort study
09 March 2012
Objective To determine whether detection of invasive cervical cancer by screening results in better prognosis or merely increases the lead time until death.
Participants All 1230 women with cervical cancer diagnosed during 1999-2001 in Sweden prospectively followed up for an average of 8.5 years.
Main outcome measures Cure proportions and five year relative survival ratios, stratified by screening history, mode of detection, age, histopathological type, and FIGO (International Federation of Gynecology and Obstetrics) stage.
Results In the screening ages, the cure proportion for women with screen detected invasive cancer was 92% (95% confidence interval 75% to 98%) and for symptomatic women was 66% (62% to 70%), a statistically significant difference in cure of 26% (16% to 36%). Among symptomatic women, the cure proportion was significantly higher for those who had been screened according to recommendations (interval cancers) than among those overdue for screening: difference in cure 14% (95% confidence interval 6% to 23%). Cure proportions were similar for all histopathological types except small cell carcinomas and were closely related to FIGO stage. A significantly higher cure proportion for screen detected cancers remained after adjustment for stage at diagnosis (difference 15%, 7% to 22%).
Conclusions Screening is associated with improved cure of cervical cancer. Confounding cannot be ruled out, but the effect was not attributable to lead time bias and was larger than what is reflected by down-staging. Evaluations of screening programmes should consider the assessment of cure proportions
BMJ 2012; 344 doi: 10.1136/bmj.e900 (Published 1 March 2012)
A. Castanon, S. Ferryman, J. Patnick and P. Sasieni Review of cytology and histopathology as part of the NHS Cervical Screening Programme audit of invasive cervical cancers
18 January 2012
To audit pathology slide reporting in the Cervical Screening Programme in England by reviewing cytology and histology slides from women subsequently diagnosed with invasive cervical cancer.
Methods: Between April 2007 and March 2010, 6113 women diagnosed with cervical cancer were identified. Cervical cytology and histology slides taken within 10 years of diagnosis were identified and where possible reviewed after a nationally agreed protocol. Reviewers were not blinded to the original reading of each sample. Most cytology samples before 2005 were conventional, most after 2007 liquid based.
Results: Of 13 745 cytology results from women developing cervical cancer, 55% were reviewed. The review result was identical for 55% of slides. Of 3759 originally normal slides, only 45% were normal on review: 11% were inadequate, 21% low grade (borderline or mild dyskaryosis) and 23% high grade (moderate dyskaryosis or worse). Of tests originally normal taken over 5.5 years before diagnosis, 14% were upgraded to high grade compared with 37% within 3.5 years of diagnosis. Of 5159 histology specimens recorded within 10 years of diagnosis of a cancer, 3895 were reviewed. Overall, 94% of samples reviewed retained the original diagnosis. One per cent (33/3012) of cancers were downgraded and 5% (6/112) of negative samples were upgraded to cancer upon review (four of which were taken within 2 months of diagnosis). In comparison, 15% (14/91) of cervical glandular intraepithelial neoplasia (CGIN) and 12% (38/314) of cervical intraepithelial neoplasia grade 3 (CIN3) were upgraded to cancer.
Conclusions: In spite of the excellent quality of cytology in England, a high proportion of negative cytology taken up to three and a half years before diagnosis were considered to contain abnormal cells by reviewers informed of the subsequent cancer. Continuing these reviews, with a strong focus on education, will ensure a clear understanding of these slides and further reduce the risk of developing cervical cancer.
Cytopathology;
Article first published online: 16 JAN 2012
DOI: 10.1111/j.1365-2303.2011.00948.x
© 2012 Blackwell Publishing Ltd
R. M. Austin and C. Zhao Type 1 and type 2 cervical carcinomas: some cervical cancers are more difficult to prevent with screening
18 January 2012
Although the Papanicolaou (Pap) smear is medical history’s most successful cancer screening test, some cervical cancers are more difficult to prevent with screening than others.
Although the Papanicolaou (Pap) smear is medical history’s most successful cancer screening test, some cervical cancers are more difficult to prevent with screening than others. Cervical cancers that are difficult to prevent are seen disproportionately among interval cancers arising in previously screened women and in Pap test litigation. These include (i) rapidly progressing cervical cancers; (ii) cervical cancers in younger women; (iii) glandular cervical cancers; and (iv) cervical cancers in elderly women. Screening protocols have generally been designed to optimize prevention of slower-growing cervical squamous carcinomas in middle-aged women. To focus further attention on the heterogeneous screening challenges posed by different cervical cancers, we designate the more screening preventable majority as type 1 cervical cancers and the more difficult to prevent minority as type 2 cervical cancers. We review available data on why some cervical cancers are more difficult to prevent with screening and newer methods that may improve prevention.
Cytopathology;
Article first published online: 16 JAN 2012
DOI: 10.1111/j.1365-2303.2011.00955.x
© 2012 Blackwell Publishing Ltd
Multinucleation of koilocytes is in fact multilobation and is related to aberration of the G2 checkpoint
10 January 2012
To clarify the fine structure of koilocytes and correlate this with genetic aberration of the G2 checkpoint.
Method;
Three dimensial reconstruction from confocal fluorescent images,together with functional assays for key molecules of the G2 checkpoint-cdc2 and cyclin B1 was performed in human uterine cervical samples.After confirming 22 HPV types using a DNA chip from 30 cervical swabs,previously confirmed as 15 cervical low grade and 15 high grade intraepithelial lesions,the activity of molecules involved in the G2 checkpoint was evaluated using Western blotting for cyclin B1,cdc2 and phospho-cdc2(Y15 and T161), a nuclear extraction fractional assay,and a reverse transciption polymerase chain reaction assay.In addition,three dimensional confocal image restoration was performed on confirmed CIN tissue samples.
Result: T161 phospho-cdc2 and cyclin B1 expression was higher in HPV infected cervical lesions than in normal samples.Immunofluorescence ,revealed that cyclin B1 was present predominantly in the nuclei of HPV infected cells,confirming the results of the nuclear fractional assay.On restoration of three dimensional confocal images ,the multinucleation of koilocytes was revealed to be multilobation of a single nucleus,rather than true multinucleation.This multilobation apeared to be associated with chromosomal instability and aberration of the G2 checkpoint.
Conclusion: The multiple nuclei of koilocytes are in fact multilobation of a single nucleus, and this phenomenon is associated with upregulation of gene products related to the G2 checkpoint
N.H. Cho et al J Clin Pathol 2005;58: 578-582
Sexual revloution effect may be hiding true extent of HPV prevalence
09 January 2012
Human papillomavirus (HPV) infection in older women is commonly due to reactivation of latent disease rather than new infection, research indicates.
The study, published in The Journal of Infectious Diseases, showed that the age-specific prevalence of HPV rose with the number of sexual partners, a finding of particular relevance to women who became sexually active during the sexual revolution of the 1960s and 1970s, say the researchers.
"Our historical experience with HPV and cervical neoplasia in postmenopausal women may not be very predictive of the experience of the baby boomer generation of women who are now entering the menopausal transition at a higher risk than their mothers," remarked study co-author Patti Gravitt (Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA) in an accompanying press statement.
Gravitt and colleagues explored age-related fluctuations in HPV infection in the USA, where the prevalence peaks among younger women around the age of sexual debut. In other geographic regions there is a second attenuated peak around the age of menopause but this bimodal distribution is not seen in the US.
"Explanations for this variability include differences in relative prevalence of new partnerships at older ages, risk of HPV reactivation at older ages, and cohort effects," writes the team.
They enrolled 843 women aged 35-60 years and tested them for HPV DNA. The women's mean age was 46.6 years, 74.3% were White, and 19.0% were Black.
The prevalence of HPV - whether all types combined or just high-risk strains - decreased with age and increased with the number of lifetime sexual partners, with a threshold observed between four and five such partners. HPV prevalence was also higher among women with a recent new sexual partner.
Interestingly, the prevalence of HPV declined with increasing age among women with fewer than five lifetime sex partners. However, among women reporting five or more lifetime partners, the prevalence of any HPV and high-risk HPV declined between ages 35-40 years, increased again during ages 40-54 years, and then decreased at ages 55-60 years.
The interaction between age and lifetime number of sex partners was modest for any HPV and statistically significant for high-risk HPV, after adjustment for recent sexual behavior, marital status, history of colposcopy, and current cytologic abnormality.
This finding is consistent with an age-associated increased risk of HPV reactivation, say the authors. The older women in this study, who experienced sexual debut at the beginning of the US sexual revolution of the 1960s and 1970s, had a lower lifetime risk for HPV infection as demonstrated by a lower self-reported lifetime number of sex partners, they note.
Gravitt and co-authors conclude: "We propose that the cohort effect of the sexual revolution in the USA is masking an increase in HPV prevalence at older ages, which may be secondary to reactivation of 'latent' infection. Further follow-up of the HPV in perimenopause cohort and national surveillance data will be required to confirm this hypothesis."
Journal of Infectious Diseases 2013