Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium

BACKGROUND

Human papillomavirus type 16 (HPV16)-E6 antibodies are detectable in peripheral blood before diagnosis in the majority of HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), but the timing of seroconversion is unknown.

PATIENTS AND METHODS

We formed the HPV Cancer Cohort Consortium which comprises nine population cohorts from Europe, North America and Australia. In total, 743 incident OPSCC cases and 5814 controls provided at least one pre-diagnostic blood sample, including 111 cases with multiple samples. Median time between first blood collection and OPSCC diagnosis was 11.4 years (IQR = 6-11 years, range = 0-40 years). Antibodies against HPV16-E6 were measured by multiplex serology (GST fusion protein based Luminex assay).

RESULTS

HPV16-E6 seropositivity was present in 0.4% of controls (22/5814; 95% CI 0.2% to 0.6%) and 26.2% (195/743; 95% CI 23.1% to 29.6%) of OPSCC cases. HPV16-E6 seropositivity increased the odds of OPSCC 98.2-fold (95% CI 62.1-155.4) in whites and 17.2-fold (95% CI 1.7-170.5) in blacks. Seropositivity in cases was more frequent in recent calendar periods, ranging from 21.9% pre-1996 to 68.4% in 2005 onwards, in those with blood collection near diagnosis (lead time <5 years). HPV16-E6 seropositivity increased with lead time: 0.0%, 13.5%, 23.7%, and 38.9% with lead times of >30 years (N = 24), 20-30 years (N = 148), 10-20 years (N = 228), and <10 years (N = 301 cases) (p-trend < 0.001). Of the 47 HPV16-E6 seropositive cases with serially-collected blood samples, 17 cases seroconverted during follow-up, with timing ranging from 6 to 28 years before diagnosis. For the remaining 30 cases, robust seropositivity was observed up to 25 years before diagnosis.

CONCLUSIONS

The immune response to HPV16-driven tumorigenesis is most often detectable several decades before OPSCC diagnosis. HPV16-E6 seropositive individuals face increased risk of OPSCC over several decades.

Design and statistical considerations for studies evaluating the efficacy of a single dose of the human papillomavirus (HPV) vaccine

Cervical cancer is a leading cause of cancer mortality in women worldwide. Human papillomavirus (HPV) types 16 and 18 cause about 70% of all cervical cancers. Clinical trials have demonstrated that three doses of either commercially available HPV vaccine, Cervarix ® or Gardasil ®, prevent most new HPV 16/18 infections and associated precancerous lesions. Based on evidence of immunological non-inferiority, 2-dose regimens have been licensed for adolescents in the United States, European Union, and elsewhere. However, if a single dose were effective, vaccine costs would be reduced substantially and the logistics of vaccination would be greatly simplified, enabling vaccination programs in developing countries. The National Cancer Institute (NCI) and the Agencia Costarricense de Investigaciones Biomédicas (ACIB) are conducting, with support from the Bill & Melinda Gates Foundation and the International Agency for Research on Cancer (IARC), a large 24,000 girl study to evaluate the efficacy of a 1-dose regimen. The first component of the study is a four-year non-inferiority trial comparing 1- to 2-dose regimens of the two licensed vaccines. The second component is an observational study that estimates the vaccine efficacy (VE) of each regimen by comparing the HPV infection rates in the trial arms to those in a contemporaneous survey group of unvaccinated girls. In this paper, we describe the design and statistical analysis for this study. We explain the advantage of defining non-inferiority on the absolute risk scale when the expected event rate is near 0 and, given this definition, suggest an approach to account for missing clinic visits. We then describe the problem of estimating VE in the absence of a randomized placebo arm and offer our solution.

Impact of human papillomavirus (HPV) 16 and 18 vaccination on prevalent infections and rates of cervical lesions after excisional treatment

BACKGROUND

Human papillomavirus (HPV) vaccines prevent HPV infection and cervical precancers. The impact of vaccinating women with a current infection or after treatment for an HPV-associated lesion is not fully understood.

OBJECTIVES

To determine whether HPV-16/18 vaccination influences the outcome of infections present at vaccination and the rate of infection and disease after treatment of lesions.

STUDY DESIGN

We included 1711 women (18–25 years) with carcinogenic human papillomavirus infection and 311 women of similar age who underwent treatment for cervical precancer and who participated in a community-based trial of the AS04-adjuvanted HPV-16/18 virus-like particle vaccine. Participants were randomized (human papillomavirus or hepatitis A vaccine) and offered 3 vaccinations over 6 months. Follow-up included annual visits (more frequently if clinically indicated), referral to colposcopy of high-grade and persistent low-grade lesions, treatment by loop electrosurgical excisional procedure when clinically indicated, and cytologic and virologic follow-up after treatment. Among women with human papillomavirus infection at the time of vaccination, we considered type-specific viral clearance, and development of cytologic (squamous intraepithelial lesions) and histologic (cervical intraepithelial neoplasia) lesions. Among treated women, we considered single-time and persistent human papillomavirus infection, squamous intraepithelial lesions, and cervical intraepithelial neoplasia 2+. Outcomes associated with infections absent before treatment also were evaluated. Infection-level analyses were performed and vaccine efficacy estimated.

RESULTS

Median follow-up was 56.7 months (women with human papillomavirus infection) and 27.3 months (treated women). There was no evidence of vaccine efficacy to increase clearance of human papillomavirus infections or decrease incidence of cytologic/histologic abnormalities associated with human papillomavirus types present at enrollment. Vaccine efficacy for human papillomavirus 16/18 clearance and against human papillomavirus 16/18 progression from infection to cervical intraepithelial neoplasia 2+ were −5.4% (95% confidence interval −19,10) and 0.3% (95% confidence interval −69,41), respectively. Among treated women, 34.1% had oncogenic infection and 1.6% had cervical intraepithelial neoplasia 2+ detected after treatment, respectively, and of these 69.8% and 20.0% were the result of new infections. We observed no significant effect of vaccination on rates of infection/lesions after treatment. Vaccine efficacy estimates for human papillomavirus 16/18 associated persistent infection and cervical intraepithelial neoplasia 2+ after treatment were 34.7% (95% confidence interval −131, 82) and −211% (95% confidence interval −2901, 68), respectively. We observed evidence for a partial and nonsignificant protective effect of vaccination against new infections absent before treatment. For incident human papillomavirus 16/18, human papillomavirus 31/33/45, and oncogenic human papillomavirus infections post-treatment, vaccine efficacy estimates were 57.9% (95% confidence interval −44, 88), 72.9% (95% confidence interval 29, 90), and 36.7% (95% confidence interval 1.5, 59), respectively.

CONCLUSION

We find no evidence for a vaccine effect on the fate of detectable human papillomavirus infections. We show that vaccination does not protect against infections/lesions after treatment. Evaluation of vaccine protection against new infections and resultant lesions warrants further consideration in future studies.

Abstract LB-181: Oral HPV DNA detection and subsequent risk of head and neck cancers in two prospective cohorts

Background: Alpha HPV16 detection in the oral cavity is associated with head and neck squamous cell carcinoma (HNSCC), particularly oropharyngeal cancer. However, there have been no prospective studies examining the temporal relationship between oral HPV detection and subsequent risk of HNSCC. Moreover, recent data indicates that the oral cavity contains a plethora of HPV types in addition to alpha HPVs (e.g. beta and/or gamma HPVs), but their association with risk of HNSCC is unknown.

Methods: We examined prospective associations between alpha, beta and gamma HPVs and risk of HNSCC, using a nested case-control design among &gt;120,000 participants with available mouthwash samples in the American Cancer Society (ACS) Cancer Prevention Study-II Nutrition Cohort (CPS-II) and the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. A total of N = 132 incident cases of HNSCC (oropharyngeal, oral and laryngeal SCCs) were identified during an average 3.94 years of follow-up (range 0.02-9.0) in both cohorts. Three controls per case (N = 396) were selected using incidence density sampling, with matching on age (±2 years), race/ethnicity, gender, and time since mouthwash collection (±3 months). Detection of HPV DNA in mouthwash samples was carried out using (1) a novel next-generation sequencing assay designed to detect all HPV types, (2) the MY09/MY11 assay targeting alpha-HPV types, and (3) a RT-PCR specific for HPV16. Associations of alpha, beta and gamma HPVs with risk of HNSCC were evaluated using conditional logistic regression models for matched risk sets to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for smoking and alcohol as well as alpha HPV16 for beta and gamma HPVs.

Results: The prevalence of oral HPV16 was 1.8% in controls. HPV16 detection was associated with a 7.1-fold higher risk of overall HNSCC (95% CI 2.2-22.6); the risk was highest for oropharyngeal cancer (OR = 22.41, 95% CI 1.8 - 276.7), while no excess was found for oral cavity or larynx cancers. There were no associations between other alpha HPVs and risk of HNSCC. Oral prevalence of any beta or gamma HPVs was 59.4% and 38.2%, respectively in controls. Detection of any beta HPV (OR = 1.74, p = 0.05) or any gamma HPV (OR = 2.11, p = 0.005) was also associated with risk of HNSCC, with several beta (β1 HPV5, β2 HPV17, β2 HPV38) and gamma (γ11, γ12) HPVs having statistically significant increased risks (ORs from 3.92 to 7.36). In regard to tumor location, β1HPV5 was associated with oropharyngeal (OR = 7.42, p = 0.05), oral cavity (OR = 5.34, p = 0.01) and laryngeal cancers (OR = 2.71, p = 0.05); while β2 HPV38 was associated with oropharyngeal cancer (OR = 7.28, p = 0.02) only. Gamma HPV species groups 11 and 12 were associated with both oral cancer (OR = 7.47, p = 0.03; and OR = 6.71, p = 0.01, respectively) and laryngeal cancers (OR = 7.49, p = 0.04 and OR = 5.31, p = 0.03).

Conclusion: This study is the first to demonstrate that alpha HPV16 detection precedes the incidence of oropharyngeal cancers. Risks identified with other HPV types from gamma11 and 12 species as well as beta HPV5, previously associated with skin cancer, suggests a broader role for HPVs in HNSCC etiology. Readily-collected oral wash samples provide a strong prospective marker for oropharyngeal cancer and, with the incorporation of other HPV types, may indicate risk for a broader spectrum of HNSCC.

Citation Format: Ilir Agalliu, Zigui Chen, Tao Wang, Rebecca Ludvigsen, Lauren Teras, Aimee R. Kreimer, Richard B. Hayes, Susan Gapstur, Robert D. Burk. Oral HPV DNA detection and subsequent risk of head and neck cancers in two prospective cohorts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-181. doi:10.1158/1538-7445.AM2015-LB-181

Abstract 4680: Efficacy of the HPV16/18 vaccine against cervical, anal, and oral HPV infection among women with and without previous HPV16/18 exposure

Background: Previous reports from the Costa Rica Vaccine Trial demonstrated strong vaccine efficacy against HPV16/18 at the cervical, anal, and oral regions separately. However, the combined “woman-level” vaccine efficacy against infections at all three anatomic sites has not been examined in women with and without previous HPV16/18 exposure.

Methods: Women aged 18-25 from the Costa Rica Vaccine Trial were randomized to be vaccinated with the HPV16/18 Vaccine (Cervarix) or a Hepatitis A vaccine at enrollment. Cervical samples were collected at every annual visit, while oral and anal samples were collected only at the four year follow-up visit. Samples were tested for alpha mucosal HPV DNA types utilizing the SPF10 PCR-DEIA-LiPA25 version 1 method. An event in the multi-site woman-level vaccine efficacy analysis (n = 4,186) was defined as a women with prevalent HPV16/18 DNA at the cervical, anal, or oral regions. Vaccine efficacies (VEs) and 95% confidence intervals (95%CIs) were computed for one-time detection of HPV16/18 in the cervical, anal, and oral regions in this intention-to-treat analysis.

Results: Four years following initial vaccination, the combined multi-site woman-level vaccine efficacy against HPV16/18 infections was 64.8%, 95%CI = 54.8-72.8. Multi-site woman-level efficacy was stronger among women without evidence of previous HPV exposure (HPV16/18 seronegative and cervical HPV16/18 DNA negative at enrollment): VE = 83.1%, 95%CI = 72.6-89.6, but was also demonstrated among women with evidence of previous HPV16/18 exposure (HPV16/18 seropositive and cervical HPV16/18 DNA negative at baseline): VE = 49.6%, 95%CI = 2.7-73.9. Further supporting the partial protection of the vaccine in previously HPV16/18-exposed women, we observed a particularly strong vaccine efficacy against HPV16/18 at more than one anatomic site (VE = 91.4%, 95%CI = 81.4-96.6). Indeed, HPV16/18-infected women were significantly less likely to be HPV16/18-infected at two or more anatomic sites in the HPV vaccine arm than the control arm (6 of 81 (7%) vs. 70 of 230 (30%), p&lt;0.01).

Discussion: This is the first study to present a combined multi-site woman-level HPV16/18 vaccine efficacy. This study found strong multi-site efficacy among those not previously exposed to cervical HPV16/18, but also suggests the vaccine may provide some protection against HPV16/18 at multiple anatomic sites among women previously exposed to HPV16/18. If confirmed, the partial protection against cervical, anal, and/or oral HPV16/18 in women previously exposed to HPV16/18 could be considered in HPV vaccination catch-up program decision-making.

Citation Format: Daniel C. Beachler, Aimee R. Kreimer, Mark Schiffman, Rolando Herrero, Sholom Wacholder, Ana Cecilia Rodriguez, Douglas R. Lowy, Carolina Porras, John T. Schiller, Silvia Jimenez, Linda Struijk, John Schussler, Allan Hildesheim, Paula Gonzalez, Costa Rica Vaccine Trial Group. Efficacy of the HPV16/18 vaccine against cervical, anal, and oral HPV infection among women with and without previous HPV16/18 exposure. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4680. doi:10.1158/1538-7445.AM2015-4680

Impact of the HIV epidemic on the incidence rates of anal cancer in the United States

BACKGROUND

The risk of anal cancer is substantially increased in HIV-infected individuals. Thus, the HIV epidemic may have influenced the increasing anal cancer trends in the United States. We estimated the impact of the HIV epidemic on trends in anal cancer incidence in the United States during 1980-2005.

METHODS

Data on anal cancer cases with and without AIDS were obtained from the HIV/AIDS Cancer Match Study. The number of HIV-infected anal cancer cases without AIDS was estimated from the number of anal cancers occurring before diagnosis of AIDS. The proportion of anal cancer cases with HIV infection in the general population was calculated. We estimated temporal trends in the incidence rates of anal cancer in the general population overall and after exclusion of HIV-infected cancer cases by calculating annual percent changes and 95% confidence intervals (CIs) using a Joinpoint log-linear model. All incidence rates were standardized to the 2000 US population by age, sex, and race.

RESULTS

During 1980-2005, of the 20 533 estimated anal cancer cases, 1665 (8.1%) were HIV-infected. During 2001-2005, the proportion of anal cancer cases with HIV infection was the highest-1.2% (95% CI = 0.93 to 1.4%) among females and 28.4% (95% CI = 26.6 to 29.4%) among males. During 1980-2005, HIV infection did not have an impact on the trends in anal cancer among females (incidence rates increased by 3.3% [95% CI = 3.0 to 3.7%] annually overall, and by 3.3% [95% CI = 2.9 to 3.6%] annually without HIV-infected anal cancer cases) but had a strong impact on the trends in anal cancer among males (incidence rates increased by 3.4% [95% CI = 2.9 to 3.9%] annually overall, and by 1.7% [95% CI = 1.2 to 2.3%] annually without HIV infection).

CONCLUSION

During 1980-2005, the increasing anal cancer incidence rates in the United States were strongly influenced by the HIV epidemic in males but were independent of HIV infection in females.

Self-reported oral hygiene habits among dental patients in Italy

OBJECTIVE

The objective of this survey was to assess oral hygiene habits and compliance with guidelines for good oral health set forth by the Italian Ministry of Health (IMH).

SUBJECTS AND METHODS

A sample of 2,200 self-administered questionnaires was sent to four dental clinics across Italy to assess sociodemographic information, oral hygiene habits, frequency of dental visits and services received at previous visits among a population of adult patients.

RESULTS

Of the 2,200 questionnaires, 1,201 (54.6%) were returned. Findings showed that full compliance with the IMH recommendations was low (12%): a small number of patients (n = 223, 18.6%) visited a dentist every 6 months and only 256 (23.5%) brushed their teeth at least twice a day.

CONCLUSION

Our data showed that regular attendance (at least 1 visit/year) at dental clinics for routine check-up and brushing teeth at least twice a day were poor. Therefore, we recommend that clinicians educate and motivate their patients about the benefits of healthy oral hygiene practices.

Prevention of persistent human papillomavirus infection by an HPV16/18 vaccine: a community-based randomized clinical trial in Guanacaste, Costa Rica

Target groups for human papillomavirus (HPV) vaccination are controversial. We evaluated vaccine efficacy (VE) against 1-year persistent infection, stratified by age and sexual behavior, among young women in Costa Rica. We randomized 7,466 healthy women 18 to 25 years of age to HPV16/18 or hepatitis A vaccine (follow-up, 50.4 months). According-to-protocol (ATP) cohorts included compliant HPV-negative women; intention-to-treat (ITT) included all randomized women. ATP VE was 90.9% (95% CI, 82.0-95.9) against HPV16/18 infections, 44.5% against HPV31/33/45 (95% CI, 17.5-63.1), and 12.4% (95% CI, -3.2 to 25.6) against any oncogenic infection. Overall ITT VE against HPV16/18 infections was 49.0%, but ATP and ITT VE almost reached 100% in year 4 of follow-up. ATP efficacy against HPV16/18 was similar by age, but ITT VE was greatest among youngest women (68.9% among those 18-19 years of age; 21.8% among those 24-25 years of age) and 79.8% among virgins. Among previously unexposed women, vaccination is highly efficacious against HPV16/18 and partially against HPV31/33/45. Vaccination is most effective in women and girls before they initiate sexual activity, with programmatic and individual decision implications.

Oral cancer knowledge: a survey administered to patients in dental departments at large Italian hospitals

We assessed the oral cancer (OC) knowledge, including risk factors and clinical symptoms, among patients attending dental departments within Italian university hospitals. Two thousand and two hundred questionnaires were sent to four hospitals in order to assess patients' knowledge regarding clinical and epidemiological aspects of OC; OC knowledge was evaluated overall and stratified by oral cancer family history. Participants frequently identified cigarette smoking (87.8%) and heavy alcohol consumption (58.6%) as a risk factor for oral cancer, knew the clinical signs of OC (65-79% depending on the specific symptom) and reported that early detection was related to better prognosis of oral cancer (94%). Individuals with a positive family history for oral cancer were significantly more likely to identify risk factors for oral cancer correctly yet family history of OC did not affect smoking status. Less than 15% of patients reported having received OC counseling by a dentist or physician.

The epidemiology of oral HPV infection among a multinational sample of healthy men

BACKGROUND

Oral human papillomavirus type-16 (HPV16) infection is a risk factor for oropharyngeal cancer. We examined oral HPV infection among healthy men.

METHODS

Oral rinse/gargle specimens and questionnaire data were collected from 1,688 healthy men aged 18 to 74 (median = 31 years), from the United States, Mexico, and Brazil. HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59, and noncarcinogenic HPV types were detected using Roche Linear Array.

RESULTS

Oral HPV DNA was detected in 67 of 1,680 (4.0%, 95% CI = 3.1%-5.0%) β-globin-positive specimens; carcinogenic HPVs were detected in 1.3% (95% CI = 0.8%-2.0%; n = 22) and HPV16 was the most commonly detected carcinogenic HPV type (0.6%, 95% CI = 0.2%-1.1%; n = 10). The prevalence of oral HPV infection was similar by country except for HPV55, which had notably higher prevalence in Mexico (3.0%) than Brazil (0%) or the United States (0.2%). Oral HPV prevalence nonsignificantly increased over increasing age categories (P(trend) = 0.096). The strongest predictor of oral HPV was current tobacco use, which increased the odds 2.5-fold (95% CI = 1.4-4.4). Oral sexual behaviors were not associated with oral HPV infection.

CONCLUSIONS

Oral HPV16 infection was rare in healthy men, especially at younger ages, and was positively associated with current tobacco use.

IMPACT

Oral HPV appears to be about 10-fold less prevalent than infection at genital sites in men (4% vs. ∼40%, respectively). It remains unclear whether this reflects reduced exposure or if the oral region is more resistant to HPV infection compared with anogenital sites.

No role for human papillomavirus in esophageal squamous cell carcinoma in China

Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically-confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh-frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type-specific E6 and E7 primers, and in formalin-fixed paraffin-embedded tumor tissue using SPF(10) L1 primers. In HPV-positive cases, we evaluated p16(INK4a) overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. beta-globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9-100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6-100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin-fixed paraffin-embedded tumor specimens, 99.3% (95% CI = 97.3-99.9%) were HPV negative by SPF(10). By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF(10), 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA-positive case had evidence of HPV oncogene activity as measured by p16(INK4a) overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.

The gastric cardia is not a target for human papillomavirus-induced carcinogenesis

BACKGROUND

Thousands of people in central Asia die every year from gastric cardia adenocarcinoma (GCA). GCA arises in the transformation zone between the esophagus and the stomach, similar to cervical and oropharyngeal carcinoma, which arise in areas with transformation zone characteristics. The analogous biology of the gastric cardia to the cervix and oropharynx, where human papillomavirus (HPV) is known to cause cancer, raises the possibility that GCA could be a HPV-associated cancer. Given the availability of an effective HPV vaccine and its potential to prevent HPV-associated cancer, we decided to evaluate the prevalence of HPV DNA in GCA.

METHODS

We collected tumor tissue from 144 histopathologically confirmed GCA patients at Yaocun Commune Hospital (Linxian, China), with rigorous attention to prevent DNA contamination. We tested for the presence of HPV DNA in fresh-frozen tumor specimens using PCR with sensitive L1-, E6-, and E7-based primers.

RESULTS

DNA was adequate, as indicated by beta-globin positivity, in 108 cases. Of these, all (100%; 95% confidence interval, 97-100%) were negative for HPV DNA.

CONCLUSIONS

These results suggest that HPV does not contribute to gastric cardia carcinogenesis in north central China.

IMPACT

Because GCA does not seem to be a HPV-associated cancer, prophylactic HPV vaccination is unlikely to affect rates of GCA in China.

Cumulative incidence of false-positive results in repeated, multimodal cancer screening

PURPOSE

Multiple cancer screening tests have been advocated for the general population; however, clinicians and patients are not always well-informed of screening burdens. We sought to determine the cumulative risk of a false-positive screening result and the resulting risk of a diagnostic procedure for an individual participating in a multimodal cancer screening program.

METHODS

Data were analyzed from the intervention arm of the ongoing Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, a randomized controlled trial to determine the effects of prostate, lung, colorectal, and ovarian cancer screening on disease-specific mortality. The 68,436 participants, aged 55 to 74 years, were randomized to screening or usual care. Women received serial serum tests to detect cancer antigen 125 (CA-125), transvaginal sonograms, posteroanterior-view chest radiographs, and flexible sigmoidoscopies. Men received serial chest radiographs, flexible sigmoidoscopies, digital rectal examinations, and serum prostate-specific antigen tests. Fourteen screening examinations for each sex were possible during the 3-year screening period.

RESULTS

After 14 tests, the cumulative risk of having at least 1 false-positive screening test is 60.4% (95% CI, 59.8%-61.0%) for men, and 48.8% (95% CI, 48.1%-49.4%) for women. The cumulative risk after 14 tests of undergoing an invasive diagnostic procedure prompted by a false-positive test is 28.5% (CI, 27.8%-29.3%) for men and 22.1% (95% CI, 21.4%-22.7%) for women.

CONCLUSIONS

For an individual in a multimodal cancer screening trial, the risk of a false-positive finding is about 50% or greater by the 14th test. Physicians should educate patients about the likelihood of false positives and resulting diagnostic interventions when counseling about cancer screening.

Breast cancer epidemiology according to recognized breast cancer risk factors in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial Cohort

Background

Multidisciplinary attempts to understand the etiology of breast cancer are expanding to increasingly include new potential markers of disease risk. Those efforts may have maximal scientific and practical influence if new findings are placed in context of the well-understood lifestyle and reproductive risk factors or existing risk prediction models for breast cancer. We therefore evaluated known risk factors for breast cancer in a cancer screening trial that does not have breast cancer as a study endpoint but is large enough to provide numerous analytic opportunities for breast cancer.

Methods

We evaluated risk factors for breast cancer (N = 2085) among 70,575 women who were randomized in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Using Poisson regression, we calculated adjusted relative risks [RRs, with 95% confidence intervals (CIs)] for lifestyle and reproductive factors during an average of 5 years of follow-up from date of randomization.

Results

As expected, increasing age, nulliparity, positive family history of breast cancer, and use of menopausal hormone therapy were positively associated with breast cancer. Later age at menarche (16 years or older vs. < 12: RR = 0.81, 95% CI, 0.65–1.02) or menopause (55 years or older vs. < 45: RR = 1.29, 95% CI, 1.03–1.62) were less strongly associated with breast cancer than was expected. There were weak positive associations between taller height and heavier weight, and only severe obesity [body mass index (BMI; kg/m²) 35 or more vs. 18.5–24.9: RR = 1.21, 95% CI, 1.02–1.43] was statistically significantly associated with breast cancer.

Conclusion

The ongoing PLCO trial offers continued opportunities for new breast cancer investigations, but these analyses suggest that the associations between breast cancer and age at menarche, age at menopause, and obesity might be changing as the underlying demographics of these factors change.

Clinical Trials Registration

http://www.clinicaltrials.gov, NCT00002540.

Case-control study of human papillomavirus and oropharyngeal cancer

BACKGROUND

Substantial molecular evidence suggests a role for human papillomavirus (HPV) in the pathogenesis of oropharyngeal squamous-cell carcinoma, but epidemiologic data have been inconsistent.

METHODS

We performed a hospital-based, case-control study of 100 patients with newly diagnosed oropharyngeal cancer and 200 control patients without cancer to evaluate associations between HPV infection and oropharyngeal cancer. Multivariate logistic-regression models were used for case-control comparisons.

RESULTS

A high lifetime number of vaginal-sex partners (26 or more) was associated with oropharyngeal cancer (odds ratio, 3.1; 95% confidence interval [CI], 1.5 to 6.5), as was a high lifetime number of oral-sex partners (6 or more) (odds ratio, 3.4; 95% CI, 1.3 to 8.8). The degree of association increased with the number of vaginal-sex and oral-sex partners (P values for trend, 0.002 and 0.009, respectively). Oropharyngeal cancer was significantly associated with oral HPV type 16 (HPV-16) infection (odds ratio, 14.6; 95% CI, 6.3 to 36.6), oral infection with any of 37 types of HPV (odds ratio, 12.3; 95% CI, 5.4 to 26.4), and seropositivity for the HPV-16 L1 capsid protein (odds ratio, 32.2; 95% CI, 14.6 to 71.3). HPV-16 DNA was detected in 72% (95% CI, 62 to 81) of 100 paraffin-embedded tumor specimens, and 64% of patients with cancer were seropositive for the HPV-16 oncoprotein E6, E7, or both. HPV-16 L1 seropositivity was highly associated with oropharyngeal cancer among subjects with a history of heavy tobacco and alcohol use (odds ratio, 19.4; 95% CI, 3.3 to 113.9) and among those without such a history (odds ratio, 33.6; 95% CI, 13.3 to 84.8). The association was similarly increased among subjects with oral HPV-16 infection, regardless of their tobacco and alcohol use. By contrast, tobacco and alcohol use increased the association with oropharyngeal cancer primarily among subjects without exposure to HPV-16.

CONCLUSIONS

Oral HPV infection is strongly associated with oropharyngeal cancer among subjects with or without the established risk factors of tobacco and alcohol use.

Human Papillomavirus Types in Head and Neck Squamous Cell Carcinomas Worldwide: A Systematic Review

Mucosal human papillomaviruses (HPV) are the cause of cervical cancer and likely a subset of head and neck squamous cell carcinomas (HNSCC), yet the global prevalence and type distribution of HPV in HNSCC remains unclear. We systematically reviewed published studies of HNSCC biopsies that employed PCR-based methods to detect and genotype HPV to describe the prevalence and type distribution of HPV by anatomic cancer site. Geographic location and study size were investigated as possible sources of variability. In the 5,046 HNSCC cancer specimens from 60 studies, the overall HPV prevalence was 25.9% [95% confidence interval (95% CI), 24.7-27.2]. HPV prevalence was significantly higher in oropharyngeal SCCs (35.6% of 969; 95% CI, 32.6-38.7) than oral SCCs (23.5% of 2,642; 95% CI, 21.9-25.1) or laryngeal SCCs (24.0% of 1,435; 95% CI, 21.8-26.3). HPV16 accounted for a larger majority of HPV-positive oropharyngeal SCCs (86.7%; 95% CI, 82.6-90.1) compared with HPV-positive oral SCCs (68.2%; 95% CI, 64.4-71.9) and laryngeal SCCs (69.2%; 95% CI, 64.0-74.0). Conversely, HPV18 was rare in HPV-positive oropharyngeal SCCs (2.8%; 95% CI, 1.3-5.3) compared with other head and neck sites [34.1% (95% CI, 30.4-38.0) of oral SCCs and 17.0% (95% CI, 13.0-21.6) of laryngeal SCCs]. Aside from HPV16 and HPV18, other oncogenic HPVs were rarely detected in HNSCC. Tumor site-specific HPV prevalence was higher among studies from North America compared with Europe and Asia. The high HPV16 prevalence and the lack of HPV18 in oropharyngeal compared with other HNSCCs may point to specific virus-tissue interactions. Small sample size and publication bias complicate the assessment of the prevalence of HPV in head and neck sites beyond the oropharynx.

Gender differences in sexual biomarkers and behaviors associated with human papillomavirus-16, -18, and -33 seroprevalence

BACKGROUND

The elevated risk for incident head and neck cancer among human papillomavirus (HPV)-16-seropositive individuals has substantiated a role for HPV in the etiology of head and neck cancers. The relationship between HPV seroreactivity and prevalent oral HPV infection in men and women without cancer has yet to be investigated.

GOAL

The goal of this study was to evaluate a possible association between oral HPV infection and HPV seroreactivity after adjustment for gender, sexual behaviors, and sexually transmitted disease.

STUDY DESIGN

A cross-sectional study of factors associated with HPV-16, -18, and -33 seroreactivity was performed in a population of 586 men and women with and without HIV infection. Antibodies in sera were measured by use of a virus-like protein (VLP)-based enzyme-linked immunosorbent assay. Exfoliated cells from the tonsillar and oral mucosa were analyzed for the presence of 38 mucosal HPV types by polymerase chain reaction.

RESULTS

Women had significantly greater seroreactivity for all HPV types investigated when compared with men (odds ratio, 4.3; 95% confidence interval, 3.0-6.0). Seroprevalence was greatest in men and women aged 35 to 45 years. Tonsillar HPV infection, oral sex with men, and HIV infection were independently associated with HPV seroreactivity in men after adjustment for age and number of sexual partners. In women, HSV-2 seropositivity and a history of sexually transmitted diseases were similarly important. Oral and tonsillar HPV infection were not associated with HPV seroreactivity in women.

CONCLUSION

HPV seropositivity is associated with sexually transmitted diseases among women and possibly mucosal HPV exposures in men. Tonsillar HPV infection could impact seroprevalence, particularly in men.

Oral human papillomavirus infection in adults is associated with sexual behavior and HIV serostatus

The prevalence and risk factors for oral human papillomavirus (HPV) infection are unknown, despite evidence for an etiological role for HPV in oral cancers. Oral samples from human immunodeficiency virus (HIV)-seronegative (n=396) and HIV-seropositive (n=190) adults were tested for HPV DNA. High-risk HPV infections were present in 2.1% of tonsil and 6.3% of oral-rinse specimens. The prevalence of oral high-risk HPV infection was greater in HIV-seropositive individuals (13.7% vs. 4.5%; P<.001). In multiple logistic regression, odds of oral HPV infection increased with age, male sex, and herpes simplex virus (HSV)-2 seropositivity in HIV-seronegative individuals and with CD4 cell count <200 cells/mL, HSV-2 seropositivity, oral mucosal abnormalities, and >1 oral sex partner during the previous year (odds ratio, 12.8; 95% confidence interval, 3.1-52.7) among HIV-seropositive individuals. HPV type 16, which is present in most HPV-associated tonsillar cancers, was the most prevalent high-risk oral HPV infection.