HPV16 variant lineage, clinical stage, and survival in women with invasive cervical cancer

Background

HPV16 variants are associated with different risks for development of CIN3 and invasive cancer, although all are carcinogenic. The relationship of HPV 16 variants to cancer survival has not been studied.

Methods

155 HPV16-positive cervical cancers were categorized according to European and non-European variant patterns by DNA sequencing of the E6 open reading frame. Clinico-pathologic parameters and clinical outcome were collected by chart review and death registry data.

Results

Of the 155 women (mean age 44.7 years; median follow-up 26.7 months), 85.2% harbored European variants while 14.8% had non-European sequences. HPV16 variants differed by histologic cell type (p = 0.03) and stage (1 vs. 2+; p = 0.03). Overall, 107 women (68.0%) were alive with no evidence of cancer, 42 (27.1%) died from cervical cancer, 2 (1.3%) were alive with cervical cancer, and 4 (2.6%) died of other causes. Death due to cervical cancer was associated with European variant status (p < 0.01). While 31% of women harboring tumors with European variants died from cervical cancer during follow-up, only 1 of 23 (4.4%) non-European cases died of cancer. The better survival for non-European cases was partly mediated by lower stage at diagnosis.

Conclusions

Overall, invasive cervical cancers with non-European variants showed a less aggressive behavior than those with European variants. These findings should be replicated in a population with more non-European cases.

The oral cavity contains abundant known and novel human papillomaviruses from the Betapapillomavirus and Gammapapillomavirus genera

BACKGROUND

Human papillomaviruses (HPVs) primarily sort into 3 genera: Alphapapillomavirus (α-HPV), predominantly isolated from mucosa, and Betapapillomavirus (β-HPV) and Gammapapillomavirus (γ-HPV), predominantly isolated from skin. HPV types might infect body sites that are different from those from which they were originally isolated.

METHODS

We investigated the spectrum of HPV type distribution in oral rinse samples from 2 populations: 52 human immunodeficiency virus (HIV)-positive men and women and 317 men who provided a sample for genomic DNA for a prostate cancer study. HPV types were detected with the MY09/MY11 and FAP59/64 primer systems and identified by dot blot hybridization and/or direct sequencing.

RESULTS

Oral rinse specimens from 35 (67%) of 52 HIV-positive individuals and 117 (37%) of 317 older male participants tested positive for HPV DNA. We found 117 type-specific HPV infections from the HIV-positive individuals, including 73 α-HPV, 33 β-HPV, and 11 γ-HPV infections; whereas, the distribution was 46 α-HPV, 108 β-HPV, and 14 γ-HPV infections from 168 type-specific infections from the 317 male participants.

CONCLUSIONS

The oral cavity contains a wide spectrum of HPV types predominantly from the β-HPV and γ-HPV genera, which were previously considered to be cutaneous types. These results could have significant implications for understanding the biology of HPV and the epidemiological associations of HPV with oral and skin neoplasia.

Proof-of-principle evaluation of the efficacy of fewer than three doses of a bivalent HPV16/18 vaccine

BACKGROUND

Three-dose regimens for human papillomavirus (HPV) vaccines are expensive and difficult to complete, especially in settings where the need for cervical cancer prevention is greatest.

METHODS

We evaluated the vaccine efficacy of fewer than three doses of the HPV16/18 vaccine Cervarix in our Costa Rica Vaccine Trial. Women were randomly assigned to receive three doses of the HPV16/18 vaccine or to a control vaccine and were followed for incident HPV16 or HPV18 infection that persisted in visits that were 10 or more months apart (median follow-up 4.2 years). After excluding women who had no follow-up or who were HPV16 and HPV18 DNA positive at enrollment, 5967 women received three vaccine doses (2957 HPV vaccine vs 3010 control vaccine), 802 received two doses (422 HPV vs. 380 control), and 384 received one dose (196 HPV vs. 188 control). Reasons for receiving fewer doses and other pre- and post-randomization characteristics were balanced within each dosage group between women receiving the HPV and control vaccines.

RESULTS

Incident HPV16 or HPV18 infections that persisted for 1 year were unrelated to dosage of the control vaccine. Vaccine efficacy was 80.9% for three doses of the HPV vaccine (95% confidence interval [CI] = 71.1% to 87.7%; 25 and 133 events in the HPV and control arms, respectively), 84.1% for two doses (95% CI = 50.2% to 96.3%; 3 and 17 events), and 100% for one dose (95% CI = 66.5% to 100%; 0 and 10 events).

CONCLUSION

Four years after vaccination of women who appeared to be uninfected, this nonrandomized analysis suggests that two doses of the HPV16/18 vaccine, and maybe even one dose, are as protective as three doses.

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.

Clustering of multiple human papillomavirus infections in women from a population-based study in Guanacaste, Costa Rica

OBJECTIVE

To evaluate clustering patterns of prevalent infection with multiple human papillomavirus (HPV) types in 8365 nonhysterectomized women from the Guanacaste Study of HPV Natural History.

METHODS

HPV testing was performed on cervical cells by MY09/M11 L1 degenerate consensus primer polymerase chain reaction method, with dot-blot hybridization for genotyping. Logistic regression was used to model type-specific HPV positivity, adjusted for age, lifetime number of sexual partners, and specific HPV type prevalence. Woman-level random effects were added to represent unobservable risk factors common to all HPV types.

RESULTS

The observed-to-expected ratio for infections with 2 types was 1.16 (95% credible interval: 1.11-1.21) and for ≥3 types was 1.04 (95% credible interval: .96-1.13). The tendency of HPV types to cluster increased significantly with the genetic similarity of L1 regions. P value < .01 was observed for 2 HPV pairs: HPV-62 and -81 were found together more, while HPV-51 and -71 were found together less often than expected.

CONCLUSIONS

We found a small degree of aggregation between any HPV types and lack of clustering between specific carcinogenic types. Our data indirectly provide reassurance on lack of misclassification for the large majority of HPV types in multiple infections detected by the MY09/11 method and genotyped using dot-blot hybridization.

Persistence of type-specific human papillomavirus infection and increased long-term risk of cervical cancer

BACKGROUND

Human papillomavirus (HPV) persistence is the pivotal event in cervical carcinogenesis. We followed a large-scale community-based cohort for 16 years to investigate the role of genotype-specific HPV persistence in predicting cervical cancer including invasive and in situ carcinoma.

METHODS

At the baseline examination in 1991-1992, 11,923 participants (aged 30-65 years) consented to HPV testing and cytology; 6923 participants were reexamined in 1993-1995. For HPV testing, we used a polymerase chain reaction-based assay that detected 39 HPV types. Women who developed cervical cancer were identified from cancer and death registries. Cumulative risks for developing cervical cancer among infected and persistently infected women were calculated by the Kaplan-Meier method.

RESULTS

Of 10,123 women who were initially cytologically normal, 68 developed cervical cancer. The 16-year cumulative risks of subsequent cervical cancer for women with HPV16, HPV58 (without HPV16), or other carcinogenic HPV types (without HPV16 or HPV58) were 13.5%, 10.3%, and 4.0%, respectively, compared with 0.26% for HPV-negative women. Women with type-specific persistence of any carcinogenic HPV had greatly increased risk compared with women who were HPV-negative at both visits (hazard ratio = 75.4, 95% confidence interval = 31.8 to 178.9). The cumulative cervical cancer risks following persistent carcinogenic HPV infections increased with age: The risks were 5.5%, 14.4%, and 18.1% for women aged 30-44 years, 45-54 years, and 55 years and older, respectively. However, newly acquired infections were associated with a low risk of cervical cancer regardless of age.

CONCLUSIONS

HPV negativity was associated with a very low long-term risk of cervical cancer. Persistent detection of HPV among cytologically normal women greatly increased risk. Thus, it is useful to perform repeated HPV testing following an initial positive test.

Efficacy of a bivalent HPV 16/18 vaccine against anal HPV 16/18 infection among young women: a nested analysis within the Costa Rica Vaccine Trial

BACKGROUND

Anal cancer remains rare (incidence of about 1·5 per 100,000 women yearly), but rates are increasing in many countries. Human papillomavirus (HPV) 16 and 18 infections cause most cases of anal cancer. We assessed efficacy of an AS04-adjuvanted HPV 16 and HPV 18 vaccine against anal infection with HPV 16, HPV 18, or both (HPV 16/18).

METHODS

Women from Costa Rica were registered between June 28, 2004, and Dec 21, 2005, in a randomised double-blind controlled trial that was designed to assess vaccine efficacy against persistent cervical HPV 16/18 infections and associated precancerous lesions. Eligible women were residents of Guanacaste and selected areas of Puntarenas, Costa Rica, age 18-25 years, in good general health, willing to provide informed consent, and were not pregnant or breastfeeding. Participants were randomly assigned (1:1) to receive an HPV vaccine (Cervarix, GlaxoSmithKline, Rixensart, Belgium) or a control hepatitis A vaccine (modified preparation of Havrix, GlaxoSmithKline, Rixensart, Belgium). Vaccines were administered in three 0·5 mL doses at enrolment, 1 month, and 6 months. Women, selected at the final blinded study visit 4 years after vaccination, provided anal specimens for assessment of vaccine efficacy against anal HPV 16/18 infection. Prevalence of anal HPV 16/18 infections, reported as vaccine efficacy, was the primary endpoint of the study described here. Vaccine efficacy against cervical HPV 16/18 infection in the same women at the 4-year visit was used as a comparator. Analyses were done in a restricted cohort of women who were negative for both cervical HPV 16 and HPV 18 DNA and who were HPV 16 and HPV 18 seronegative before enrolment (HPV naive), and also in the full cohort of women who provided an anal specimen. Investigators were masked to group assignment. This study is registered at ClinicalTrials.gov, number NCT00128661.

FINDINGS

All women who attended the final blinded study visit and consented to anal specimen collection were included in the analysis (4210 of 6352 eligible women). In the full cohort, vaccine efficacy against prevalent HPV 16/18 infection measured one-time, 4 years post vaccination was lower at the anus (62·0%, 95% CI 47·1-73·1) compared with the cervix (76·4%, 67·0-83·5; p for interaction by anatomical site 0·031). In the restricted cohort, vaccine efficacy against anal HPV 16/18 infection was 83·6% (66·7-92·8), which was similar to vaccine efficacy against cervical HPV 16/18 infection (87·9%, 77·4-94·0). Safety issues were not addressed in the current analysis. Additional safety data will be published later in a separate article.

INTERPRETATION

The AS04-adjuvanted vaccine affords strong protection against anal HPV infection, particularly among women more likely to be HPV naive at enrolment.

FUNDING

National Cancer Institute with contributions from the National Institutes of Health Office of Research on Women's Health. Vaccine was provided by GlaxoSmithKline Biologicals.

Long-term risk of recurrent cervical human papillomavirus infection and precancer and cancer following excisional treatment

Risk of recurrent CIN2+ (including cervical intraepithelial neoplasia grade 2 [CIN2], CIN3, carcinoma and in situ, adenocarcinoma in situ or cancer) remains elevated for years following treatment. The role of long-term post-treatment human papillomavirus (HPV) presence on subsequent risk of CIN2+ was evaluated in the 10,049-women Guanacaste cohort. Six hundred eighty-one women were referred to colposcopy because of high-grade cytology, positive cervicography and/or suspicion of cancer based on visual assessment; 486 were judged to require treatment. After excluding women with <12 months of follow-up (N = 88), prior cancer or hysterectomy (N = 37) or other reasons (N = 14), 347 were included in the analysis. Infections were categorized as persistent if present at both pre- and post-treatment visits and new if detected only post-treatment. Median time between the treatment and post-treatment visits was 6.7 years (interquartile range 3.8-7.8). At the post-treatment visit, 8 (2.4%), 2 (0.6%) and 8 (2.4%) of the 347 treated women had persistent HPV16, HPV18 or other carcinogenic HPV, respectively. Two (0.8%), 3 (1.0%) and 13 (4.0%) had new HPV16, HPV18 and other carcinogenic HPV, respectively. Six CIN2+ cases were identified at the post-treatment visit, all with persistent infections (three HPV16, one HPV18 and two other carcinogenic HPV). No recurrent disease was observed among women with new HPV infections during the follow-up period. Thus, persistence of HPV infection a median of six years after treatment was uncommon but, when present, posed a substantial risk of subsequent CIN2+. Serial follow-up data from other studies would further strengthen these conclusions.

Switch from cytology-based to human papillomavirus test-based cervical screening: implications for colposcopy

Human papillomavirus (HPV) testing is more sensitive than cytology; some cervical cancer prevention programs will switch from cytology to carcinogenic HPV test-based screening. The objective of our study is to evaluate the clinical implications of a switch to HPV test-based screening on performance and workload of colposcopy. Women in the population-based, 7-year Guanacaste cohort study were screened at enrollment using cytology. We also took another specimen for HPV DNA testing and collected magnified cervical photographic images (cervigrams). A final case diagnosis (≥cervical intraepithelial neoplasia [CIN] grade 3, CIN2, <CIN2) was assigned at exit. Using the cervigram as a surrogate of colposcopy impression, we evaluated the impact of changing screening method from cytology to carcinogenic HPV testing on the distribution of enrollment colposcopic impression and on the predictive values of positive and negative colposcopic impressions for the cumulative 7-year detection of ≥CIN2 and ≥CIN3. A program based on immediate colposcopic referral after positive HPV would immediately identify as high risk more of the cumulative ≥CIN2 cases than conventional cytology, because of an increased number of referrals. However, the proportion of women that would have visible lesions at referral to colposcopy and the sensitivity versus specificity trade-off of the colposcopic impressions would be similar to programs using cytology (≥ atypical squamous cells of unknown significance [ASCUS]) for referral. The major concern with switching from cytology to more sensitive HPV screening is management of the many HPV-positive women, including those with still nonvisible ≥CIN2 lesions. Our data support the need for a nonvisual diagnostic method to guide management and treatment of HPV-positive women.

A competitive serological assay shows naturally acquired immunity to human papillomavirus infections in the Guanacaste Natural History Study

BACKGROUND

A competitive Luminex Immunoassay (cLIA) has been developed to measure neutralizing antibodies against human papillomavirus (HPV) types 6, 11, 16 and 18.

METHODS

In a cohort of 974 women from the Guanacaste Natural History Study, we studied the relationship of baseline cLIA and virus-like particle (VLP) enzyme-linked immunosorbent assay (ELISA) (HPV16 and HPV18 only) seropositivity to measures of HPV exposure, HPV DNA positivity, number of sexual partners, cytology findings, and age. We then studied immunity against subsequent infection with HPV6, 11, 16, 18 and related types over a 7-year period.

RESULTS

cLIA seroprevalence varied with previous exposure; the prevalence of cLIA results positive for HPV16 and HPV18 was lower than the prevalence of positive VLP ELISA responses. cLIA and VLP ELISA positivity predicted protection from subsequent infections with concordant types. The combined odds ratio for HPV16 and HPV18 cLIA positivity was 0.41 (95% confidence interval [CI], 0.21-0.80), and the combined odds ratio for the HPV16 and HPV18 VLP ELISA positivity was 0.65 (95% CI, 0.46-0.93). Of individual types, statistical significance was only reached for HPV16 cLIA positivity (odds ratio, 0.44; 95% CI, 0.15-0.94).

CONCLUSIONS

Both assays showed an association between positive results and significant protection from subsequent infections for HPV16 and HPV18 combined. cLIA seroprevalence was lower than VLP ELISA, suggesting that the assay detects a subset of antibodies following natural infection that are specifically linked to immunity against subsequent HPV infection.

A population-based cross-sectional study of age-specific risk factors for high risk human papillomavirus prevalence in rural Nigeria

Background

Cervical cancer, caused by persistent infection with carcinogenic human papillomavirus (HR-HPV), is particularly prevalent in Sub-Saharan Africa and is associated with a high mortality rate. Some studies in West Africa, including our own, have found unusually high HR-HPV across all ages with a slight peak in older women. This increased prevalence at older ages may complicate screen-and-treat programs, which are implemented in regions where HPV prevalence declines with age and typically target women between 30-49 years. A better understanding of the determinants of high HR-HPV prevalence at older ages is needed. The goal of this study is to explore risk factors for HR-HPV prevalence by age among women in our population-based study in Irun, a rural town in southwestern Nigeria.

Methods

1,420 women were administered a clinic-based questionnaire regarding sexual and reproductive behavior, marital status (including co-wives), and malaria exposure. Logistic regression compared questionnaire responses and PCR positivity for a set of 13 carcinogenic HR-HPV types. Results were stratified by age (15-29, 30-45, 46-55, and 56+ years).

Results

Birth control use and age at first pregnancy were associated with HR-HPV (p-value = 0.03 and 0.05, respectively). Early age at sexual debut and multiple sex partners were risks for HR-HPV, but did not reach significance (p-value = 0.1 and 0.07, respectively). Neither self-reported malaria nor presence of co-wives in the household was associated with HR-HPV (p-value = 0.85 and 0.24, respectively). In age sub-categories, early age at sexual debut was a significant risk factor for HR-HPV among women 35-45 years (p-value = 0.02). Early age at first pregnancy remained a significant risk factor for women aged 56+ years (p-value = 0.04). Greater than 2 sex partners and use of birth control were associated (though not significantly) with HR-HPV in women aged 30-45 (p-value = 0.08, respectively).

Conclusions

In this high-risk region with elevated HR-HPV prevalence at older ages, we confirmed previously described, behavioral determinants of HR-HPV. There was no association with self-reported malaria or co-wives, which we had hypothesized might correlate with HR-HPV at older ages.

Cervical cancer risk for women undergoing concurrent testing for human papillomavirus and cervical cytology: a population-based study in routine clinical practice

BACKGROUND

Concurrent testing for human papillomavirus (HPV) and cervical cytology (co-testing) is an approved alternative to cytology alone in women aged 30 years and older. We aimed to assess the safety in routine clinical practice of 3-year screening intervals for women testing negative for HPV with normal cytology and to assess if co-testing can identify women at high risk of cervical cancer or cervical intraepithelial neoplasia grade 3 (CIN3) or worse over 5 years.

METHODS

We assessed the 5-year cumulative incidence, starting in 2003-05, of cervical cancer and CIN3 or worse for 331,818 women aged 30 years and older who enrolled in co-testing at Kaiser Permanente Northern California (Berkeley, CA, USA) and had adequate enrolment co-test results. Follow-up continued until Dec 31, 2009. We defined cumulative incidence to include prevalence at enrolment and incidence after enrolment. Prevalence at enrolment was defined as the ratio of women diagnosed with each outcome on the biopsy visit immediately after their enrolment screening visit to the total enrolled women. At screening visits only HPV test and Pap smear samples were collected, and at biopsy visits colposcopically directed biopsies were taken. To estimate post-enrolment incidence, we used Weibull survival models.

FINDINGS

In 315,061 women negative by HPV testing, the 5-year cumulative incidence of cancer was 3.8 per 100,000 women per year, slightly higher than for the 306,969 who were both negative by HPV and Pap testing (3.2 per 100,000), and half the cancer risk of the 319,177 who were negative by Pap testing (7.5 per 100,000). 313,465 (99.5%) women negative by HPV testing had either normal cytology or equivocal abnormalities. Abnormal cytology greatly increased cumulative incidence of CIN3 or worse over 5 years for the 16,757 positive by HPV testing (12.1%vs 5.9%; p<0.0001). By contrast, although statistically significant, abnormal cytology did not increase 5-year risk of CIN3 or worse for women negative by HPV testing to a substantial level (0.86%vs 0.16%; p=0.004). 12,208 (73%) of the women positive by HPV testing had no cytological abnormality, and these women had 258 (35%) of 747 CIN3 or adenocarcinoma in situ, [corrected] 25 (29%) of 87 cancers, and 17 (63%) of 27 adenocarcinomas.

INTERPRETATION

For women aged 30 years and older in routine clinical practice who are negative by co-testing (both HPV and cytology), 3-year screening intervals were safe because a single negative test for HPV was sufficient to reassure against cervical cancer over 5 years. Incorporating HPV testing with cytology also resulted in earlier identification of women at high risk of cervical cancer, especially adenocarcinoma. Testing for HPV without adjunctive cytology might be sufficiently sensitive for primary screening for cervical cancer.

FUNDING

Intramural Research Program of the US National Cancer Institute/NIH/DHHS, and the American Cancer Society.

Sequence imputation of HPV16 genomes for genetic association studies

BACKGROUND

Human Papillomavirus type 16 (HPV16) causes over half of all cervical cancer and some HPV16 variants are more oncogenic than others. The genetic basis for the extraordinary oncogenic properties of HPV16 compared to other HPVs is unknown. In addition, we neither know which nucleotides vary across and within HPV types and lineages, nor which of the single nucleotide polymorphisms (SNPs) determine oncogenicity.

METHODS

A reference set of 62 HPV16 complete genome sequences was established and used to examine patterns of evolutionary relatedness amongst variants using a pairwise identity heatmap and HPV16 phylogeny. A BLAST-based algorithm was developed to impute complete genome data from partial sequence information using the reference database. To interrogate the oncogenic risk of determined and imputed HPV16 SNPs, odds-ratios for each SNP were calculated in a case-control viral genome-wide association study (VWAS) using biopsy confirmed high-grade cervix neoplasia and self-limited HPV16 infections from Guanacaste, Costa Rica.

RESULTS

HPV16 variants display evolutionarily stable lineages that contain conserved diagnostic SNPs. The imputation algorithm indicated that an average of 97.5±1.03% of SNPs could be accurately imputed. The VWAS revealed specific HPV16 viral SNPs associated with variant lineages and elevated odds ratios; however, individual causal SNPs could not be distinguished with certainty due to the nature of HPV evolution.

CONCLUSIONS

Conserved and lineage-specific SNPs can be imputed with a high degree of accuracy from limited viral polymorphic data due to the lack of recombination and the stochastic mechanism of variation accumulation in the HPV genome. However, to determine the role of novel variants or non-lineage-specific SNPs by VWAS will require direct sequence analysis. The investigation of patterns of genetic variation and the identification of diagnostic SNPs for lineages of HPV16 variants provides a valuable resource for future studies of HPV16 pathogenicity.

A long-term prospective study of type-specific human papillomavirus infection and risk of cervical neoplasia among 20,000 women in the Portland Kaiser Cohort Study

BACKGROUND

Human papillomavirus (HPV) DNA testing is more sensitive than cytology for detection of cervical intraepithelial neoplasia grade 3 and cancer (≥CIN3). Adding HPV testing to cytology is recommended for women ≥30 but long-term prospective studies of HPV testing are rare.

METHODS

Beginning in 1989-1990, ~20,000 women in a prepaid health maintenance organization (median age = 34) were followed passively by recommended annual cytology. We tested archived cervicovaginal lavage specimens collected at enrollment, primarily by MY09-MY11 PCR-based methods, for carcinogenic HPV types. We calculated positive and negative predictive values for the entire study period, and Kaplan-Meier estimates of cumulative probability for ≥CIN3, up to 18 years of follow-up.

RESULTS

We observed 47 cases of invasive cervical cancer during the study period, and 156 cases of CIN3. Predictive values and Kaplan-Meier analyses yielded the same conclusions. In women 30 and older, the reassurance against ≥CIN3 following a single negative HPV test was long-lasting (cumulative probability = 0.7% during follow-up). In this age group, a single HPV test (positive vs. negative, hazard ratio of 8.5, 95% CI = 4.8-15.1) provided greater long-term risk stratification than a single cytologic result (abnormal vs. normal, HR = 2.9, 95% CI = 1.2-6.6). The risk for ≥CIN3 was higher for HPV16 than for the average of the other carcinogenic types (hazard ratio = 2.7).

CONCLUSION AND IMPACT

The data from this cohort study show the long-term predictive value of HPV testing, particularly in women ≥30, and a possible role for distinguishing particularly carcinogenic types like HPV16.

Human papillomavirus infection with multiple types: pattern of coinfection and risk of cervical disease

OBJECTIVE

We investigated coinfection patterns for 25 human papillomavirus (HPV) types and assessed the risk conferred by multiple HPV types toward cervical disease.

METHODS

Sexually active women (n=5,871) in the NCI-sponsored Costa Rica HPV Vaccine Trial's prevaccination enrollment visit were analyzed. Genotyping for 25 HPVs was performed using SPF(10)/LiPA(25). We calculated odds ratios (ORs) to assess coinfection patterns for each genotype with 24 other genotypes. These ORs were pooled and compared with pair-specific ORs to identify genotype combinations that deviated from the pooled OR. We compared risk of CIN2+/HSIL+between multiple and single infections and assessed additive statistical interactions.

RESULTS

Of the 2478 HPV-positive women, 1070 (43.2%) were infected with multiple types. Multiple infections occurred significantly more frequently than predicted by chance. However, this affinity to be involved in a coinfection (pooled OR for 300 type-type combinations=2.2; 95% confidence interval [CI]=2.1-2.4) was not different across HPV type-type combinations. Compared with single infections, coinfection with multiple α9 species was associated with significantly increased risk of CIN2+(OR=2.2; 95% CI=1.1-4.6) and HSIL+(OR=1.6; 95% CI=1.1-2.4). However, disease risk was similar to the sum of estimated risk from individual types, with little evidence for synergistic interactions.

CONCLUSIONS

Coinfecting HPV genotypes occur at random and lead to cervical disease independently.

Human papillomavirus (HPV) genotypes in women with cervical precancer and cancer at Kaiser Permanente Northern California

BACKGROUND

The human papillomavirus (HPV) Persistence and Progression Cohort is a natural history study of carcinogenic HPV positive women. Here, we present the HPV genotypes found in first ∼500 cases of cervical intraepithelial neoplasia grade 3 (CIN3) or more severe disease (CIN3+) diagnosed at the study baseline.

METHODS

Women aged 30 and older were screened for cervical cancer using Pap smears and tested for carcinogenic HPV using Hybrid Capture 2 (HC2; Qiagen). We randomly selected women who tested HPV positive and were diagnosed with CIN3+ (n = 448) or without CIN3+ (

RESULTS

Among HC2-positive women, HPV16 (48.9%), HPV31 (9.2%), and HPV18 (8.5%) were the most common HPV genotypes in CIN3+. There was a decrease at older ages in the fraction of CIN3 (P(trend) = 0.006), adenocarcinoma in situ (AIS) (P(trend) = 0.08), and CIN3/AIS (P(trend) = 0.002) associated with HPV16. Compared to the other carcinogenic HPV genotypes in aggregate, HPV18 was strongly associated with CIN3+ in women with a normal Pap [odds ratio (OR) = 5.7, 95% CI = 1.2-26] but not in women with abnormal Pap (OR = 1.3, 95% CI = 0.74-2.3).

CONCLUSIONS

HPV16 is more strongly associated with cervical precancer diagnosed in younger women (vs. older women). HPV18 infections were linked to precancerous lesions that were missed by cytology.

IMPACT

The progression timeline of HPV16 differs from other carcinogenic HPV genotypes, which may impact the use of HPV16 detection in the management of HPV-positive women.

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Key Words

• pap
• cervical intraepithelial neoplasia (cin)
• cervical cancer
• human papillomavirus (hpv)
• atypical squamous cells of undetermined significance (asc-us)
• hybrid capture 2 (hc2)

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MESH Headings

• Adenocarcinoma/genetics
• Adenocarcinoma/pathology
• Adenocarcinoma/virology
• Adult
• California
• Carcinoma, Squamous Cell/genetics
• Carcinoma, Squamous Cell/pathology
• Carcinoma, Squamous Cell/virology
• Cohort Studies
• DNA, Viral/genetics
• Female
• Genotype
• Humans
• Papanicolaou Test
• Papillomaviridae/classification
• Papillomaviridae/genetics
• Papillomavirus Infections/genetics
• Papillomavirus Infections/pathology
• Papillomavirus Infections/virology
• Polymerase Chain Reaction
• Precancerous Conditions/genetics
• Precancerous Conditions/pathology
• Precancerous Conditions/virology
• Prognosis
• Risk Factors
• Uterine Cervical Neoplasms/genetics
• Uterine Cervical Neoplasms/pathology
• Uterine Cervical Neoplasms/virology
• Vaginal Smears
• Uterine Cervical Dysplasia/genetics
• Uterine Cervical Dysplasia/pathology
• Uterine Cervical Dysplasia/virology

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Grants

• R01 CA078527 NCI NIH HHS
• U01 CA078527 NCI NIH HHS
• Z01 CP010124 Intramural NIH HHS
• Z01 CP010124-12 Intramural NIH HHS

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Abstract 1991: Methylation of the HPV16 L1 gene is associated with disease progression in a prospective population-based cohort

Persistent infection with one of the carcinogenic types of human papillomavirus (HPV) is the primary cause of cervical cancer, the 3rd most commonly diagnosed cancer worldwide. HPV type 16 is the most prevalent HPV type, the most persistent, and is found in about half of all cancers. Only a small minority of women infected with HPV16 progress to cervical precancer, with a substantial fraction of those eventually developing invasive cancer. The viral and host determinants of transitions to HPV 16 infection clearance, persistence and progression to precancer are still largely unknown.

CpG methylation can be used as a defense mechanism against expression from foreign, e.g. viral, DNA. Methylation of HPV DNA by infected cells may alter viral expression patterns relevant for viral infection and transformation. The goal of our study was to evaluate whether DNA methylation in the late structural gene, L1, or the upstream regulatory region (URR) of HPV16 are associated with clearance of infection, persistence without progression to precancer, or progression to precancer among women in the prospective Guanacaste, Costa Rica cohort.

HPV16 DNA was extracted from cervical cells collected prior to diagnosis from 36 women randomly selected from each of the 3 main infection outcomes that can be distinguished within the cohort: 1) women who cleared their HPV16 infection, 2) women with persistent HPV16 infection without progression to precancer (defined as CIN3), and 3) women with HPV16 infection who progressed to precancer (CIN3). DNA was bisulfite modified and methylation was quantified using pyrosequencing assays at 16 CpG sites in L1 and 16 CpGs in URR. The Kruskal-Wallis test was used to determine if methylation at each individual CpG site was associated with disease outcome. To account for multiple testing, the Benjamini-Hochberg method was used to ensure the expected proportion of false positives was less than 0.05. To determine whether methylation of L1 or URR was associated with disease outcome, incorporating information from all sites in each region, a global test based on the minimum of the P-values was performed. The P-value corresponding to the global test was obtained via permutation.

Methylation at six different CpG sites in the L1 region were found to be associated with outcome status (P = 0.01-0.0008). The L1 region was significantly associated with the disease outcome (Global P = 0.008). At each differentially methylated CpG site in the L1 region, we noted increased methylation with each transition towards precancer. No significant associations were detected with the URR region or the individual CpG sites in this region.

Viral CpG methylation of L1 might alter gene expression and thereby influence infection outcome. This is the first study to prospectively analyze outcomes related to baseline HPV16 methylation of L1 and URR and to suggest that methylation of L1 may be driving viral progression to precancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1991. doi:10.1158/1538-7445.AM2011-1991

Long-term persistence of prevalently detected human papillomavirus infections in the absence of detectable cervical precancer and cancer

BACKGROUND

Detailed descriptions of long-term persistence of human papillomavirus (HPV) in the absence of cervical precancer are lacking.

METHODS

In a large, population-based natural study conducted in Guanacaste, Costa Rica, we studied a subset of 810 initially HPV-positive women with ≥ 3 years of active follow-up with ≥ 3 screening visits who had no future evidence of cervical precancer. Cervical specimens were tested for >40 HPV genotypes using a MY09/11 L1-targeted polymerase chain reaction method.

RESULTS

Seventy-two prevalently-detected HPV infections (5%) in 58 women (7%) persisted until the end of the follow-up period (median duration of follow-up, 7 years) without evidence of cervical precancer. At enrollment, women with long-term persistence were more likely to have multiple prevalently-detected HPV infections (P < .001) than were women who cleared their baseline HPV infections during follow-up. In a logistic regression model, women with long-term persistence were more likely than women who cleared infections to have another newly-detected HPV infection detectable at ≥ 3 visits (odds ratio, 2.6; 95% confidence interval, 1.2-5.6).

CONCLUSIONS

Women with long-term persistence of HPV infection appear to be generally more susceptible to other HPV infections, especially longer-lasting infections, than are women who cleared their HPV infections.

Abstract 3189: Misclassification of cervical precancer: Impact of a new colposcopy protocol on disease ascertainment and biomarker performance

Introduction: Cytology-based screening for and treatment of cervical precancers has led to substantial reduction of cervical cancer incidence and mortality worldwide. Current screening approaches have limited accuracy, however, and lead to misclassification of cervical precancer at the levels of primary screening, colposcopic evaluation, and histological evaluation. We designed the Biopsy Study to systematically evaluate the extent of misclassification of cervical precancer at colposcopy.

Methods: Previously-untreated women referred to the University of Oklahoma colposcopy clinic for abnormal screening results were enrolled. Before colposcopy, a specimen was taken for liquid-based cytology, HPV genotyping, and biomarker studies. During colposcopy, a digital image of the cervix was taken and annotated for observed lesions and biopsy sites. Up to four colposcopically directed biopsies were taken from distinct lesions; if less than four targeted biopsies were obtained, a random biopsy was added. All biopsies were ranked by severity based on visual impression and evaluated individually in histology. Three cervical cancer screening tests, Pap cytology, HPV DNA testing, and p16/ki67 cytology, were evaluated against disease endpoints based on the most severely appearing biopsy (representing the current clinical standard) and based on the worst histology result from all four biopsies.

Results: To date, more than 450 women have been enrolled in the study; 86% of women had at least three, and 64% had four biopsies taken. For 377 women, a histological diagnosis was available. Forty-one of 377 women (10.8%) had CIN3, 119 (31.6%) had CIN2, 82 (35.3%) had CIN1, and 84 (22.3%) had benign changes or normal results as worst histological result. In 70.7% of women, the precancer was detected in the first biopsy, in 22.0% it was found at the second biopsy and in 7.3% it was detected in the third or fourth biopsies. Cervical cancer screening tests were evaluated in a subset of 241 women. The specificity of HPV DNA, Pap cytology, and p16/ki67 for the detection of CIN2+ increased by 6%, 7.5%, and 11.8%, respectively when the improved gold standard was applied. Meanwhile, the sensitivity of all screening tests was not reduced.

Discussion: Current colposcopy-biopsy protocols have limited sensitivity in detecting prevalent cervical precancer. In our study, we quantified the incremental benefit of taking multiple biopsies to detect cervical precancer. In the interim analysis, adding a second targeted biopsy improved disease detection by over 20%. The improved sensitivity of colposcopy resulted in decreased misclassification of cervical disease and a more accurate evaluation of cervical cancer screening tests.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3189. doi:10.1158/1538-7445.AM2011-3189

Viral load in the natural history of human papillomavirus type 16 infection: a nested case-control study

BACKGROUND

Viral load may influence the course of human papillomavirus type 16 (HPV-16) infection.

METHODS

This case-control study was nested within the 2-year Atypical Squamous Cells of Undetermined Significance and Low-Grade Squamous Intraepithelial Lesion Triage Study, in which women were followed semiannually for HPV and cervical intraepithelial neoplasia (CIN). Case patients (n = 62) were women diagnosed with CIN3 following HPV-16-positive detection at a follow-up visit. HPV-16-positive controls (n = 152) without CIN2 or CIN3 were matched to cases based on the follow-up visit in which viral load was measured. Real-time polymerase chain reaction was used for HPV-16 DNA quantification.

RESULTS

The risk of CIN3 increased with increasing HPV-16 DNA load at the follow-up visit (odds ratio, 1.63; 95% confidence interval, 1.33-1.99 per 1 log(10) unit increase); the association was not affected by whether HPV-16 was present at enrollment. When HPV-16 was present at both enrollment and follow-up, viral load remained high among cases (P = .77) but decreased substantially among controls (P = .004). Among women with HPV-16 found initially during follow-up, viral load in the first HPV-16-positive sample was associated with short-term persistence; load was higher in those with infection, compared with those without infection, 1 visit after the initial positivity (P = .001).

CONCLUSIONS

Viral load of newly detected infections and changes in viral load predict persistence and progression of HPV-16 infections.

Human papillomavirus testing in the prevention of cervical cancer

Strong evidence now supports the adoption of cervical cancer prevention strategies that explicitly focus on persistent infection with the causal agent, human papillomavirus (HPV). To inform an evidence-based transition to a new public health approach for cervical cancer screening, we summarize the natural history and cervical carcinogenicity of HPV and discuss the promise and uncertainties of currently available screening methods. New HPV infections acquired at any age are virtually always benign, but persistent infections with one of approximately 12 carcinogenic HPV types explain virtually all cases of cervical cancer. In the absence of an overtly persistent HPV infection, the risk of cervical cancer is extremely low. Thus, HPV test results predict the risk of cervical cancer and its precursors (cervical intraepithelial neoplasia grade 3) better and longer than cytological or colposcopic abnormalities, which are signs of HPV infection. The logical and inevitable move to HPV-based cervical cancer prevention strategies will require longer screening intervals that will disrupt current gynecologic and cytology laboratory practices built on frequent screening. A major challenge will be implementing programs that do not overtreat HPV-positive women who do not have obvious long-term persistence of HPV or treatable lesions at the time of initial evaluation. The greatest potential for reduction in cervical cancer rates from HPV screening is in low-resource regions that can implement infrequent rounds of low-cost HPV testing and treatment.