Human papillomavirus genotype in cervical cancer: a population-based study

Human papillomavirus prevalence, genotype distribution, and prognostic factors of vaginal cancer

We aimed to investigate human papillomavirus (HPV) prevalence and genotype distribution and prognostic factors in vaginal cancer (VC). VC patients who received treatment between 1989 and 2020 were retrospectively reviewed. L1 general polymerase chain reaction (PCR) followed by HPV Blot (King Car, I-Lan, Taiwan) and E6 type-specific-PCR were performed for genotyping firstly. P16 and p53 immunohistochemistry staining was performed. Univariate and multivariate analyses identified predictors of clinical outcomes.79 VC patients were eligible for analysis. 73 patients (92.4%) were squamous cell carcinoma (SCC) and 6 (7.6%) as non-SCC. The median follow-up time was 134.3 months (range 0.9-273.4). Among nine initially HPV-negative cases, seven were identified as being positive through HPV16/18/45/52/58 whole-genome amplification followed by Sanger sequencing (WGASS). HPV DNA sequences were detected in 98.6% of SCC and 83.3% of non-SCC, respectively, with HPV16 (49.4%), HPV52 (15.2%) and HPV58 (8.9%) being predominant. Patients with paraaortic lymph node (LN) metastasis had a 5-year cancer-specific survival (CSS) rate of 0%. Multivariate analysis revealed that only p16 and stage were significantly correlated with prognosis. Variables with strong correlations (p16- and HPV-positivity, LN metastasis and stage), were included in models 2-5 alternatively. Stage III/IV (hazard ratio [HR] = 3.64-4.56) and LN metastasis (HR = 2.81-3.44) were significant negative predictors of CSS, whereas p16-positivity (HR = 0.29-0.32) and HPV-positivity (HR = 0.14) were related to better prognosis. In conclusion, 97.5% of VCs were HPV-positive with WGASS. Stage III/IV and LN metastasis were significant negative predictors, whereas p16- and HPV-positivity were significantly associated with better prognosis.

Trend of HPV Molecular Epidemiology in the Post-Vaccine Era: A 10-Year Study

Cervical cancer, a major health concern among women worldwide, is closely linked to human papillomavirus (HPV) infection. This study explores the evolving landscape of HPV molecular epidemiology in Taiwan over a decade (2010-2020), where prophylactic HPV vaccination has been implemented since 2007. Analyzing data from 40,561 vaginal swab samples, with 42.0% testing positive for HPV, we reveal shifting trends in HPV genotype distribution and infection patterns. The 12 high-risk genotypes, in order of decreasing percentage, were HPV 52, 58, 16, 18, 51, 56, 39, 59, 33, 31, 45, and 35. The predominant genotypes were HPV 52, 58, and 16, accounting for over 70% of cases annually. The proportions of high-risk and non-high-risk HPV infections varied across age groups. High-risk infections predominated in sexually active individuals aged 30-50 and were mixed-type infections. The composition of high-risk HPV genotypes was generally stable over time; however, HPV31, 33, 39, and 51 significantly decreased over the decade. Of the strains, HPV31 and 33 are shielded by the nonavalent HPV vaccine. However, no reduction was noted for the other seven genotypes. This study offers valuable insights into the post-vaccine HPV epidemiology. Future investigations should delve into HPV vaccines' effects and their implications for cervical cancer prevention strategies. These findings underscore the need for continued surveillance and research to guide effective public health interventions targeting HPV-associated diseases.

The Clinical and Economic Impact of a Nonavalent Versus Bivalent Human Papillomavirus National Vaccination Program in Taiwan

OBJECTIVES

This study aimed to estimate the epidemiologic and economic impact of a nonavalent human papillomavirus (HPV) vaccination program for 13- to 14-year-old females compared with that of the bivalent vaccine in Taiwan.

METHODS

A previously developed dynamic transmission model for the nonavalent HPV vaccine was adapted to the Taiwan setting. The natural history of cervical cancer and genital warts was simulated by the HPV model assuming an 80% vaccination coverage rate in girls aged 13 to 14 years of age with a 2-dose schedule for the nonavalent and bivalent HPV vaccines. A lifetime duration of vaccine protection was assumed for the HPV vaccine types.

RESULTS

The model estimated that the nonavalent HPV vaccine would prevent an additional 15 951 cervical cancer cases, 6600 cervical cancer-related deaths, 176 702 grade 2 or grade 3 cervical intraepithelial neoplasia cases, 103 959 grade 1 cervical intraepithelial neoplasia cases, and 1 115 317 genital warts cases compared with the bivalent HPV vaccine. The nonavalent HPV vaccination program was projected to cost an additional New Taiwan dollars (NTD) 675.21 per person and to produce an additional 0.00271 quality-adjusted life-year per person over 100 years compared with the bivalent HPV vaccine. Thus, the incremental cost-effectiveness ratio of the nonavalent HPV vaccine versus the bivalent HPV vaccine was NTD 249 462/quality-adjusted life-year.

CONCLUSIONS

A nonavalent HPV vaccination program for 13- to 14-year-old girls would have additional public health and economic impacts and would be highly cost-effective compared with the bivalent HPV vaccine, relative to per capita gross domestic product, which is estimated at NTD 746 526 for Taiwan.

Understanding the impact of high-risk human papillomavirus on oropharyngeal squamous cell carcinomas in Taiwan: A retrospective cohort study

BACKGROUND AND OBJECTIVES

Human papillomavirus (HPV)-driven oropharyngeal squamous cell carcinoma (OPSCC) is increasing globally. In Taiwan, HPV-positive OPSCC is obscured by tobacco, alcohol, and betel quid use. We investigated the role of high-risk HPV (hrHPV) in a large retrospective Taiwan OPSCC cohort.

METHODS AND RESULTS

The cohort of 541 OPSCCs treated at Chang Gung Memorial Hospital from 1998-2016 consisted of 507 men (94%) and 34 women (6%). Most used tobacco (81%), alcohol (51%), and betel quid (65%). Formalin-fixed, paraffin-embedded tissue was used for p16 staining (a surrogate marker for HPV) and testing for HPV DNA presence and type by Multiplex HPV PCR-MassArray. HPV DNA and/or p16 staining (HPV-positive) was found in 28.4% (150/528) tumors. p16 and HPV DNA were strongly correlated (F < 0.0001). HPV16 was present in 82.8%, and HPV58 in 7.5% of HPV-positive tumors. HPV was associated with higher age (55.5 vs. 52.7 years, p = 0.004), lower T-stage (p = 0.008) better overall survival (OS) (hazard ratio [HR] 0.58 [95% CI 0.42-0.81], p = 0.001), and disease-free survival (DFS) (HR 0.54 [95% CI 0.40-0.73], p < 0.0001). Alcohol was strongly associated with recurrence and death (OS: HR 2.06 [95% CI 1.54-2.74], p < 0.0001; DFS: HR 1.72 [95% CI 1.33-2.24], p < 0.0001). OS and DFS in HPV-positive cases decreased for alcohol users (p < 0.0001). Obscured by the strong alcohol effect, predictive associations were not found for tobacco or betel quid.

CONCLUSIONS

As with HPV-positive OPSCC globally, HPV is an increasingly important etiological factor in Taiwanese OPSCC. HPV-positive OPSCC has considerable survival benefit, but this is reduced by alcohol, tobacco, and betel quid use. hrHPV is a cancer risk factor in males and females. Vaccinating both sexes with a multivalent vaccine including HPV58, combined with alcohol and tobacco cessation policies will be effective cancer-prevention public health strategies in Taiwan.

Anti-cervical cancer activity of secondary metabolites of endophytic fungi from Ginkgo biloba

OBJECTIVES

The purpose of this study was to isolate the secondary metabolites of endophytic fungi from Ginkgo biloba (SMEFGB) and investigate their anti-cervical cancer activity.

METHODS

SMEFGB were cultured. The secondary metabolites of endophytic fungi was extracted, purified and identified. The effects of secondary metabolites on proliferation, apoptosis and migration of human cervical cancer HeLa cells were determined. In addition, the effects of SMEFGB on growth of Hela implanted tumor in mice were investigated.

RESULTS

In 9 stains of endophytic fungi successfully isolated from the leaves of Ginkgo biloba, the stain J-1, J-2 and J-3 could produce podophyllotoxin. These 3 stains were identified by molecular biology. The secondary metabolites of stain J-1, J-2 and J-3 markedly inhibited the proliferation of HeLa cells, promoted their apoptosis and blocked their migration. In addition, the secondary metabolites of stain J-1, J-2 and J-3 significantly attenuated the growth of HeLa implanted tumor in mice.

CONCLUSIONS

Our results indicated that SMEFGB had obvious anti-cervical cancer activity in vitro and in vivo.

Identification of Long Noncoding RNA Expression Profiles in HPV-Negative Cervical Cancer

AIM

HPV-negative cervical cancer (CC) usually appears more aggressive and causes poorer survival outcomes compared to HPV-positive cases. However, the research in regard to HPV-negative CC is rare, and the related molecular mechanism underlying remains unclear. We intended to explore the expression profiles of long noncoding RNAs (lncRNAs) and identify the tumor-associated lncRNAs which might be used as the potential biomarker for HPV-negative CC.

METHODS

Bioinformatics analyses were utilized to construct the expression profiles of lncRNAs, Gene Ontology, and KEGG analyses and draw the lncRNA-mRNA co-expression network in HPV-negative CC. The expression levels of the top 5 marked-up tumor-associated lncRNAs were detected by qRT-PCR. The effect of LINC00115 on CC growth and metastasis was studied by Cell Counting Kit-8 and transwell assays.

RESULTS

In comparison to normal cervix (NC), 2,052 lncRNAs were differentially expressed in HPV-negative CC. It demonstrated that LINC00115 was significantly upregulated in HPV-negative CC cells compared to NC, and it could promote proliferation, migration, and invasion of HPV-negative CC cells.

CONCLUSION

LINC00115 might be a potential biomarker for HPV-negative CC.

Role of human papillomavirus status after conization for high-grade cervical intraepithelial neoplasia

Human papillomavirus (HPV) is the well‐established etiologic factor for cervical neoplasia. Cervical conization constitutes an effective treatment for high‐grade cervical intraepithelial neoplasia (HG‐CIN). We conducted an observational study for long‐term outcomes and HPV genotype changes after conization for HG‐CIN. Between 2008 and 2014, patients with newly diagnosed HG‐CIN before conization (surveillance new [SN] group) and those who had undergone conization without hysterectomy (surveillance previous [SP] group) were enrolled. HPV testing and Pap smear were performed periodically for the SN and SP (collectively S) groups. All other patients receiving conization for HG‐CIN during the study period were identified from our hospital database. Those eligible but not enrolled into our study were assigned to the non‐surveillance (non‐S) group. For the S group (n = 493), the median follow‐up period was 74.3 months. Eighty‐four cases had recurrent CIN Grade 2 or worse (CIN2+) (5‐year cumulative rate: 14.8%), of which six had invasive cancer. Among the 84 patients, 65 (77.4%) exhibited type‐specific persistence in the paired HPV results, whereas only 7 (8.3%) harbored new HPV types that belonged to the 9‐valent vaccine types. Among the 7397 non‐S patients, 789 demonstrated recurrent CIN2+, of which 57 had invasive cancer. The stages distribution of those progressed to invasive cancer in the non‐S group were more advanced than the S group (P = .033). Active surveillance might reduce the severity of those progressed to cancer. Because a majority of the patients with recurrent CIN2+ had persistent type‐specific HPV infections, effective therapeutic vaccines are an unmet medical need.

What's new?

High‐grade cervical intraepithelial neoplasia (HG‐CIN), a cervical carcinoma precursor, frequently is caused by high‐risk human papillomavirus (hr‐HPV) infection. HG‐CIN can be treated by cervical conization, though the procedure does not eradicate hr‐HPV, potentially enabling CIN recurrence. Here, in Taiwanese patients, investigation of HPV genotype changes in relation to HG‐CIN status after conization shows that 77.4 percent of patients with recurrent CIN 2 grade or worse (CIN2+) after conization had persistent type‐specific HPV infections. Vaccination against the remaining high‐risk HPVs prevented recurrent CIN2+ in only 8.3 percent of patients, revealing an unmet need for effective therapeutic vaccines.

Human Papillomavirus 58 E7 T20I/G63S Variant Isolated from an East Asian Population Possesses High Oncogenicity

Human papillomavirus (HPV) type 58 is the third most commonly detected HPV type in cervical cancer among Eastern Asians. Our previous international epidemiological studies revealed that HPV58 carrying an E7 natural variant, T20I/G63S (designated V1), was associated with a higher risk of cervical cancer. We recently showed that V1 possesses a greater ability to immortalize and transform primary cells, as well as degrading pRB more effectively, than the prototype and other common variants. In this study, we performed a series of phenotypic and molecular assays using physiologically relevant in vitro and in vivo models to compare the oncogenicity of V1 with that of the prototype and other common natural variants. Through activation of the AKT and K-Ras/extracellular signal-regulated kinase (ERK) signaling pathways, V1 consistently showed greater oncogenicity than the prototype and other variants, as demonstrated by increased cell proliferation, migration, and invasion, as well as induction of larger tumors in athymic nude mice. This study complements our previous epidemiological and molecular observations pinpointing the higher oncogenicity of V1 than that of the prototype and all other common variants. Since V1 is more commonly found in eastern Asia, our report provides insight into the design of HPV screening assays and selection of components for HPV vaccines in this region.IMPORTANCE Epidemiological studies have revealed that a wild-type variant of HPV58 carrying an E7 variation, T20I/G63S (V1), is associated with a higher risk of cervical cancer. We previously reported that this increased oncogenicity could be the result of the virus's greater ability to degrade pRB, thereby leading to an increased ability to grow in an anchorage-independent manner. In addition to this, this report further showed that this HPV variant induced activation of the AKT and K-Ras/ERK signaling pathways, thereby explaining its genuine oncogenicity in promoting cell proliferation, migration, invasion, and formation of tumors, all to a greater extent than the prototype HPV58 and other common variants.

HPV-negative tumors of the uterine cervix

Human papillomaviruses (HPV) are the causative agents of virtually all cervical carcinomas. Nevertheless, a small proportion of cervical cancer are negative for HPV, although the significance of this finding remains unclear. We aimed to provide insight into the differential clinico-pathological characteristics of this unusual subset of HPV-negative cervical cancer. We performed HPV-DNA detection using a highly sensitive PCR test (SPF10) and p16 immunostaining in 214 cervical carcinomas specimens from women treated at the Gynecological Oncology Unit of the Hospital Clinic (Barcelona, Spain) from 2012 to 2015. The clinical and pathological characteristics, including disease-free survival and overall survival, of HPV-negative and -positive cervical carcinomas were compared. Twenty-one out of 214 tumors (10%) were negative for HPV DNA. HPV-negative tumors were more frequently of the non-squamous type (9/21, 43% vs. 37/193, 19%; p < 0.01) and showed negative p16 staining (9/21; 43% vs. 7/193; 4%; p < 0.01). HPV-negative tumors were more frequently diagnosed at advanced FIGO stage (19/21, 91% vs. 110/193, 57%; p < 0.01) and more frequently had lymph node metastases (14/21, 67% vs. 69/193, 36%; p < 0.01). Patients with HPV-negative cervical cancer had a significantly worse disease-free survival (59.8 months, 95% confidence interval 32.0-87.6 vs. 132.2 months, 95% confidence interval 118.6-145.8; p < 0.01) and overall survival (77.0 months, 95% confidence interval 47.2-106.8 vs. 153.8 months, 95% confidence interval 142.0-165.6; p = 0.01) than women with HPV-positive tumors. However, only advanced FIGO stage and lymph node metastases remained associated with a poor disease-free survival and overall survival on multivariate analysis. In conclusion, our results suggest that a low percentage of cervical cancer arise via an HPV-independent pathway. These HPV-negative tumors are diagnosed at advanced stages, show higher prevalence of lymph nodes metastases and have an impaired prognosis.

Meta-Analysis of Polymorphic Variants Conferring Genetic Risk to Cervical Cancer in Indian Women Supports CYP1A1 as an Important Associated Locus

Objective: Association of multiple polymorphic variants with cervical cancer has been elucidated by several candidate gene based as well as genome-wide association studies. However, contradictory outcomes of those studies have failed to estimate the true effect of the polymorphic variants on cervical cancer. Methods: Literature mining of the PubMed database was done to gather all the publications related to genetic association with cervical cancer in India. Out of 98 PubMed hits only 29 genetic association studies were selected for meta-analysis based on specific inclusion criteria. A fixed-effect meta-analysis was performed to evaluate the overall association of the genetic polymorphisms with cervical cancer. Cochran’s Q test was performed to assess between study heterogeneity. Publication bias was also estimated by funnel plots and Egger’s regression test. Further, sub-group analysis was conducted by fixed-effect meta-regression to assess the impact of polymorphisms on cervical cancer in the presence of Human Papilloma Virus (HPV). Result: Following a fixed-effect model, meta-analysis was conducted that revealed 2 polymorphic variants viz. ‘deletion polymorphism (Del2) (OR=1.79, 95% CI= 1.08-2.95, P=0.023) in GSTM1’ and ‘rs1048943 (OR = 2.34, 95% CI=1.37-3.99, P=0.0018) in CYP1A1’ to be associated with cervical cancer. However, multiple testing correction showed only rs1048943 of CYP1A1 to be significantly associated (P-value=0.029) with cervical cancer with significant publication bias (P-value=0.0113) as estimated by Egger’s regression test. The polymorphic variants ‘rs1801131’, ‘rs1801133’, ‘rs2430561’, ‘rs1799782’, ‘rs25486’ and ‘rs25487’ showed significant (p<0.05) evidence of heterogeneity between studies by Cochran’s Q test and also by heterogeneity index (I2) calculation. Conclusion: Therefore, our study revealed significant association of rs1048943 in CYP1A1, but a nominal association of deletion polymorphism (Del2) in GSTM1 with cervical cancer, which provides a comprehensive insight on the true effect of the polymorphisms, reported in various case-control studies, on the risk of the development of cervical cancer in Indian women.

Strong SOX10 expression in human papillomavirus-related multiphenotypic sinonasal carcinoma: report of 6 new cases validated by high-risk human papillomavirus mRNA in situ hybridization test

Human papillomavirus (HPV)-related multiphenotypic sinonasal carcinoma (HMSC) is associated with high-risk HPV (HR-HPV) infection. Using HR-HPV messenger RNA (mRNA) in situ hybridization (ISH), we reported 6 new HMSC cases and compared their histopathology with that of sinonasal adenoid cystic carcinoma. Using p16 immunohistochemistry (IHC) and HR-HPV ISH, we retrospectively identified 6 HMSC cases. All HMSC cases were positive for HR-HPV mRNA ISH and p16 IHC. Two HMSC cases had overlying atypical squamous epithelium, and 1 had invasive squamous cell carcinoma (SCC). All HMSC cases were SOX10 positive, whereas the overlying atypical squamous epithelium and the SCC were SOX10 negative. One atypical HMSC-like case was also identified, which was positive for HR-HPV mRNA ISH, HR-HPV DNA ISH, and SOX10 IHC, but negative for p16 IHC. This study showed that HR-HPV mRNA ISH was a useful tool to diagnose HMSC and had stronger signals compared with HR-HPV DNA ISH. HR-HPV E6/E7 mRNA could be identified in the overlying atypical squamous epithelium and the invasive SCC. A combination of p16 and SOX10 IHC will be a useful screening panel for HMSC followed by confirmatory HR-HPV mRNA ISH test.

Searching for human oncoviruses: Histories, challenges, and opportunities

Oncoviruses contribute significantly to cancer burden. A century of tumor virological studies have led to the discovery of seven well-accepted human oncoviruses, cumulatively responsible for approximately 15% of human cancer cases. Virus-caused cancers are largely preventable through vaccination. Identifying additional oncoviruses and virus-caused tumors will advance cancer prevention and precision medicine, benefiting affected individuals, and society as a whole. The historic success of finding human oncoviruses has provided a unique lesson for directing new research efforts in the post-sequencing era. Combing the experiences from these pioneer studies with emerging high-throughput techniques will certainly accelerate new discovery and advance our knowledge of the remaining human oncoviruses.

Surgical staging identified false HPV-negative cases in a large series of invasive cervical cancers

OBJECTIVE

We examined a large series of biopsy-proven invasive cervical cancers with surgical staging and HPV re-testing to estimate the relevance of HPV-negative cervical cancers in a Caucasian population.

METHODS

We prospectively collected smears from 371 patients with a biopsy-proven diagnosis of cervical cancer for HC2 testing of high-risk HPV (HR-HPV). In HC2-negative cases, smears and paraffin embedded tissue blocks underwent additional HPV genotyping.

RESULTS

HC2 tests showed 31/371 cases (8.8%) had negative findings. Surgical staging showed that 21/31 HC2-negative cases (68%) were not cervical cancer. Overall, 340/350 cases of primary cervical cancer confirmed by surgical staging tested HC2 positive (97.2%). Non-high-risk HPV subtypes were detected in five cases (one HPV-53, one HPV-70, and three HPV-73) and high-risk subtypes in four patients with HC2-negative cervical cancer (two HPV 16 and two HPV-18). The remaining case, a primary undifferentiated carcinoma of the uterine cervix, tested negative for HPV-DNA with all tests.

CONCLUSIONS

The main explanation for HPV-negative cervical cancer was a false diagnosis, followed by cancers associated with non-HR-HPV types, and false-negative HR-HPV results. Truly HPV negative seem to be very rare in Caucasian populations. Retrospective analyses without surgical staging may overestimate the proportion of HPV negative cervical cancers.

Human papillomavirus genotype affects metastatic rate following radiotherapy in patients with uterine cervical cancer

Human papillomavirus (HPV) infection is well known as a major etiological risk factor associated with carcinogenesis in uterine cervical cancer. However, few reports have investigated the association between HPV genotype and outcome in patients with uterine cervical cancer following radiotherapy (RT). The aim of the present study was to investigate the association between the HPV genotype and clinical outcome following RT in Japanese patients with uterine cervical cancer. Between November 2001 and August 2006, 157 Japanese women with uterine cervical cancer were treated with RT or concurrent chemoradiotherapy with curative intent. Pretreatment, formalin-fixed, paraffin-embedded biopsies were obtained from 83 patients. HPV genotypes were determined using the polymerase chain reaction method. Patients were categorized, according to HPV L1 protein sequence homology, into the HPV α-9 (HPV 16, 31, 33, 52, and 58), HPV α-7 (HPV 18, 39, 45, 59, and 68) or 'other' (HPV 51 and 56) groups. Associations between HPV genotype and clinical outcome following RT were evaluated. A total of 54 (65.1%) tumors were HPV α-9-positive, 13 (15.7%) were HPV α-7-positive, 2 (2.4%) were categorized under 'other' and 14 (16.9%) were HPV-negative. There were no significant differences in age, FIGO stage, regional lymph node metastases rate at diagnosis, or concurrent chemotherapy administration between the HPV α-9 and α-7 groups. The median follow-up period was 52 months (range, 2-156 months). The 5-year disease-free survival rates were 54.5 and 30.8% in the HPV α-9 and α-7 groups, respectively (P=0.034), and the 5-year distant metastasis rates were 38.0 and 69.2%, respectively (P=0.015). There were no significant differences in the 5-year local control or overall survival (OS) rates between the two groups. HPV genotype affected the 5-year distant metastatic rate, however not the 5-year local control or OS rate in patients with uterine cervical cancer following RT.

Clinical cancer chemoprevention: From the hepatitis B virus (HBV) vaccine to the human papillomavirus (HPV) vaccine

Approximately 2 million new cancer cases are attributed to infectious agents each year worldwide. Vaccines for the hepatitis B virus (HBV), a risk factor of hepatocellular cancer, and human papillomavirus (HPV), a risk factor of cervical cancer, are considered major successes in clinical chemoprevention of cancer. In Taiwan, the first evidence of cancer prevention through vaccinations was provided by HBV vaccination data in infants. The Taiwanese HBV vaccination program has since become a model immunization schedule for newborns worldwide. Persistent infection with high-risk HPV is generally accepted as prerequisite for cervical cancer diagnosis; however, cervical cancer is a rare complication of HPV infections. This is due to the fact that such infections tend to be transient. The safety and efficacy of both available HPV quadrivalent vaccine and bivalent vaccine are not in doubt at the present time. Until a human cytomegalovirus (CMV) vaccine becomes available, simple hygienic practices, such as hand washing, can prevent CMV infection both before and during pregnancy. Each country should establish her official guidelines regarding which vaccines should be used to treat various conditions, the target population (i.e., universal or limited to a selected population), and the immunization schedules. After a vaccine is recommended, decisions regarding reimbursement by the public health care fund are evaluated. The guidelines become part of the immunization schedule, which is updated annually and published in the official bulletin. In conclusion, both HBV and HPV vaccines are considered major successes in the chemoprevention of cancer.

Self-sampling HPV test in women not undergoing Pap smear for more than 5 years and factors associated with under-screening in Taiwan

BACKGROUND/PURPOSE

Under-utilization of Papanicolaou (Pap) smear causes a gap in the prevention of cervical neoplasms. A prospective population-based study was conducted investigating whether a self-sampling human papillomavirus (HPV) test was feasible for under-users of Pap smear and factors associated with under-screening in Taiwan.

METHODS

Women not having Pap smear screening for > 5 years were invited to participate in this study. Invitation letters and educational brochures were mailed to 4% of randomly selected eligible women from Taoyuan City, Taiwan, and responders received an HPV self-sampling kit. Those with HPV-positive results were recalled for a Pap smear and colposcopy.

RESULTS

Between March 2010 and June 2012, 10,693 women were invited, 354 responded (3.3%), and 282 (2.6%) gave valid informed consent, answered the questionnaire, and submitted HPV samples. The median age of enrolled women was 48.1 years. Forty-seven women (16.7%) had a positive HPV test, and 14 women accepted further survey to find two CIN2+. Another two cases of CIN2+ were identified from a national registry database. The cost of direct mailing self-samplers was less than that done on request (from NT$434,866 to NT$164,229, response rate of 5% to 15%, respectively, versus NT$683,957 for detecting 1 CIN2+). Reasons for not attending screening included lack of time, embarrassment, assumed low risk, fear of positive results, and perceived potential pain. Among the responders, 90.8% found the method acceptable.

CONCLUSION

Our study indicated that different approaches (e.g., direct mailing self-samplers to under-users and/or various educational interventions) must be explored to improve coverage in populations with culture characteristics similar to Taiwan.

HPV-negative carcinoma of the uterine cervix: a distinct type of cervical cancer with poor prognosis

OBJECTIVE

Using highly sensitive polymerase chain reaction (PCR) techniques, we reanalysed all cervical carcinomas (CCs) found to be human papillomavirus (HPV)-negative by Hybrid Capture 2 (HC2) to determine the prevalence of true HPV-negativity. We also evaluated the characteristics of the patients with tumours with confirmed HPV-negativity.

DESIGN

Observational study.

SETTING

Barcelona, Spain.

POPULATION

A cohort of 136 women with CC (32 adenocarcinomas, 104 squamous cell carcinomas) who had pre-treatment HC2 testing.

METHODS

All negative cases were reanalysed and genotyped for HPV using three PCR assays (SPF10, GP5+/6+ and E7-specific assay).

MAIN OUTCOME MEASURES

Percentage of confirmed HPV-negative and HPV-positive tumours. Clinicopathological features and disease-free survival (DFS) and overall survival (OS) of both groups.

RESULTS

Fourteen of 136 women (10.2%) were negative for HPV by HC2. After reanalysis by PCR-based techniques only 8/136 (5.8%) tumours were confirmed as HPV-negative, whereas in six cases different HPVs were identified [HPV-11, -16 (two tumours), -18, -45, and -68]. Confirmed HPV-negativity was more frequent in adenocarcinomas than in squamous cell carcinomas (5/32, 15.6% versus 3/104, 2.9%, respectively; P = 0.017). Patients with CCs with confirmed HPV-negativity had significantly worse DFS than women with HPV-positive tumours [51.9 months (95% CI 12.2-91.7 months) versus 109.9 months (95% CI 98.2-121.5 months); P = 0.010]. In the multivariate analysis HPV-negativity and International Federation of Gynecology and Obstetrics (FIGO) staging were associated with increased risk of progression and mortality.

CONCLUSIONS

An HC2-negative result is an uncommon finding in women with CC, but in almost half of these cases HPVs are identified by more sensitive techniques. CCs with confirmed HPV-negativity are more frequently adenocarcinomas, and seem to be associated with worse DFS.

Clinical implications of human papillomavirus genotype in cervical adeno-adenosquamous carcinoma

BACKGROUND

Our aims were to evaluate the genotype distribution of human papillomavirus (HPV) and the correlation between HPV parameters and clinicopathological/treatment variables with prognosis in cervical adeno-adenosquamous carcinoma (AD/ASC).

PATIENTS AND METHODS

Consecutive patients who received primary treatment for cervical AD/ASC International Federation of Gynecology and Obstetrics (FIGO) stages I-IV between 1993 and 2008 were retrospectively reviewed. Prognostic models were constructed and followed by internal validation with bootstrap resampling.

RESULTS

A total of 456 AD/ASC patients were eligible for HPV genotyping, while 452 were eligible for survival analysis. HPV18 was detected in 51.5% and HPV16 in 36.2% of the samples. Age >50 years old, FIGO stages III-IV and HPV16-negativity were significantly related to cancer relapse, and age >50, FIGO stages III-IV, HPV16-negativity and HPV58-positivity were significant predictors for cancer-specific survival (CSS) by multivariate analyses. HPV16-positivity was also significantly associated with good prognosis in those receiving primary radiotherapy or concurrent chemoradiation (RT/CCRT) (CSS: hazard ratio 0.41, 95% confidence interval 0.21-0.78). Patients with FIGO stages I-II and HPV16-negative AD/ASC treated with primary RH-PLND had significantly better CSS (p<0.0001) than those treated with RT/CCRT.

CONCLUSIONS

Age >50 years old, FIGO stages III-IV and HPV16-negativity were significant poor prognostic factors in cervical AD/ASC. Patients with HPV16-negative tumour might better be treated with primary surgery (e.g. radical hysterectomy for stages I-II and pelvic exenteration for stage IVA). Those with unresectable HPV16-negative tumour (stage IIIB) should undergo CCRT in combination with novel drugs. The inferences of a single-institutional retrospective study require prospective studies to confirm.

High-resolution melting molecular signatures for rapid identification of human papillomavirus genotypes

Background

Genotyping of human papillomarvirus (HPV) is crucial for patient management in a clinical setting. This study accesses the combined use of broad-range real-time PCR and high-resolution melting (HRM) analysis for rapid identification of HPV genotypes.

Methods

Genomic DNA sequences of 8 high-risk genotypes (HPV16/18/39/45/52/56/58/68) were subject to bioinformatic analysis to select for appropriate PCR amplicon. Asymmetric broad-range real-time PCR in the presence of HRM dye and two unlabeled probes specific to HPV16 and 18 was employed to generate HRM molecular signatures for HPV genotyping. The method was validated via assessment of 119 clinical HPV isolates.

Results

A DNA fragment within the L1 region was selected as the PCR amplicon ranging from 215–221 bp for different HPV genotypes. Each genotype displayed a distinct HRM molecular signature with minimal inter-assay variability. According to the HRM molecular signatures, HPV genotypes can be determined with one PCR within 3 h from the time of viral DNA isolation. In the validation assay, a 91% accuracy rate was achieved when the genotypes were in the database. Concomitantly, the HRM molecular signatures for additional 6 low-risk genotypes were established.

Conclusions

This assay provides a novel approach for HPV genotyping in a rapid and cost-effective manner.

Prevalence of Human Papillomavirus Genotypes in Cervical Cancer

Background and Objective

Cervical cancer is the second most common female genital cancer worldwide. There is strong epidemiological and molecular evidence indicating that human papillomavirus (HPV) infection is a necessary event in the development of cervical intraepithelial lesion and subsequent invasive carcinoma. The aim of this study was to investigate the HPV genotype distribution and prevalence in cervical cancer of Thai women.

Materials and Methods

One hundred fifty-five cervical cancer specimens were enrolled in this study. The HPV genotypes were determined by means of the combined use of a line probe assay (INNO-LiPA) and DNA chip methods.

Results

Of the overall prevalence of HPV in the study group, 83.2% and 11.6% of the cases had single and multiple genotype infections, respectively. The most prevalent genotypes were HPV 16 (51%), followed by HPV 18 (20%), HPV 52 (10.3%), HPV 58 (5.8%), and HPV 33 (4.5%). All HPV genotypes found in this study could be classified as 13 high-risk HPV, 2 low-risk HPV, and 2 additional types. Of the specimens, 94.8% had at least one high-risk HPV genotype infection.

Conclusion

As for the potential benefits of commercially available prophylactic vaccines to prevent HPV infection in Thailand, both vaccines (bivalent and quadrivalent) can protect from HPV-related cervical cancer in only approximately 71%. Therefore, screening programs such as routine Papanicolaou test, cytology, and HPV DNA detection are still essential for cervical cancer prevention. Moreover, future generations of HPV vaccines should also include the other most common genotypes and decrease the severe adverse effects reported at the present time.

Human papillomavirus in vaginal intraepithelial neoplasia

There are limited data on the prevalence and distribution of human papillomavirus (HPV) genotypes in vaginal intraepithelial neoplasia (VAIN). We sought to clarify this issue in a series of 450 VAIN cases with a confirmed diagnosis between 1990 and 2006. HPV genotyping was performed using paraffin-embedded specimens and polymerase chain reaction (PCR)-based methods. Multiple HPV types were validated by E6 type-specific PCR and direct sequencing. The HPV genotypes of the vaginal and cervical neoplasms were compared for those with incident VAIN and a history of previous/concomitant cervical neoplasms. Ki-67 was performed for supporting diagnosis of VAIN. Of these 450 VAIN cases (median age, 59 years; range, 19-93), two with missing paraffin blocks and 54 with poor DNA quality were excluded. HPV was detected in 273/394 (69.3%) VAIN, and multiple infections were found in 17.9% of HPV-positive samples. The leading types were HPV16 (35.5%), HPV58 (9.9%), HPV52 (9.9%), HPV39 (8.4%), HPV33 (7.3%) and HPV53 (7.0%). Among the 156 cases with a history of previous cervical neoplasia, 29.0% had concordant HPV genotypes, while synchronous VAIN samples (n = 49) were more likely to harbor concordant genotypes (58.7%) with the concomitant cervical neoplasm (p = 0.0003). Whether those HPV types in the incident VAIN lesions had existed in the vaginal epithelium at the time of the previous cervical neoplasia or a new acquisition needs to be clarified in prospective follow-up studies.

Cost-effectiveness analysis for Pap smear screening and human papillomavirus DNA testing and vaccination

INTRODUCTION

As the effectiveness of cytology-based screening programme for cervical cancer in mortality reduction has reached a plateau, various preventive strategies have been considered, including intensive Pap smear screening and the supplemental use of human papillomavirus (HPV) DNA test or HPV vaccination. Cost and effectiveness of these various preventive strategies are therefore of great concern for health policy makers.

OBJECTIVE

We intended to assess whether the combination of HPV DNA testing or HPV vaccination with Pap smear screening programme or the sole annual Pap smear screening is more effective and cost-effective in prevention of cervical cancer than the existing triennial Pap smear screening programme.

METHODS

A Markov decision model was constructed to compare total costs and effectiveness between different preventive strategies (including annual Pap smear, HPV DNA testing or HPV vaccination together with Pap smear screening programme) as opposed to the triennial Pap smear screening alone (the comparator). Probabilistic cost-effectiveness (C-E) analysis was adopted to plot a series of simulated incremental C-E ratios scattered over C-E plane and also to yield the acceptability curve for different comparisons of strategies. The threshold of vaccine cost and the influence of attendance rate were also investigated.

RESULTS

Compared with triennial Pap smear screening programme, most of preventive strategies cost more but gain additional life years (quadrant I of C-E plane) except HPV DNA testing with Pap smear every 5 years dominated by triennial Pap smear screening programme. The most cost-effective strategy was annual Pap smear (incremental C-E ratio = $31 698), followed by HPV DNA testing with Pap smear every 3 years ($36 627), and vaccination programme with triennial Pap smear screening ($44 688) with the corresponding cost-effective probabilities by the acceptability curve being 65.52%, 52.08% and 35.84% given the threshold of $40 000 of willingness to pay. Vaccination combined with triennial Pap smear would be as cost-effective as annual Pap smear provided the cost of vaccination was lowered to $250 per full course of injection.

CONCLUSIONS

Among various preventive strategies annual Pap smear screening programme is still the most cost-effective and additional HPV DNA testing is a cost-effective choice under a reasonable threshold of willingness to pay. Vaccination programme in combination with triennial screening would be cost-effective if vaccine cost can be greatly reduced in a large economic scale.

Age factor and implication of human papillomavirus type-specific prevalence in women with normal cervical cytology

The prevalence and genotype distribution of human papillomavirus (HPV) infection in women with normal cervical cytology varies widely according to the population studied. Two non-overlapping population-based cohort studies of women aged ⩾30 years for the periods 2008–2009 (n=5026) and 2004–2005 (n=10 014) were analysed. The prevalence rate of HPV was 11·0% (95% CI 10·5–11·6). HPV infection was significantly associated with age, menopausal status, and inversely associated with hormone replacement therapy. There was an increasing trend of α3/α15, α5/α6, and multiple HPV infections with increasing age. The five most common types were HPV52, 18, 53, 58 and 70, while HPV16, 31, 33 ranked 21st, 25th, and 16th, respectively, in the merged cohort with normal cytology (n=14 724). HPV16, 31, and 33 were significantly associated with abnormal cytology, which could have resulted in their rarity in the total merged cohort (n=15 040).

Human papillomavirus genotype in cervical intraepithelial neoplasia grades 2 and 3 of Taiwanese women

We aimed to assess the distribution of human papillomavirus (HPV) genotypes in high-grade cervical lesions in Taiwan. The study included 1,086 paraffin-embedded, formaldehyde-fixed cervical intraepithelial neoplasia (CIN) 2/3 specimens. HPV genotyping was performed using polymerase chain reaction (PCR)-based methods. Multiple HPV types were validated by E6 type-specific PCR, direct sequencing and/or real-time PCR. HPV DNA was detected in 995 (91.6%) specimens, and multiple HPV types were identified in 192 (19.3%) samples. The leading HPV types were HPV16 (24%), HPV52 (20%), HPV58 (20%), HPV33 (13%), HPV31 (8%) and HPV18 (4.6%). Although the leading six types consisted of 87.6%, HPV16 or 18 comprised only 30.9%. The prevalence of different HPV types showed a significant association with age. In women older than 50 yr, HPV16 and 18 comprised 21.3% (83/389), while HPV52, 58 and 33 represented 55.5% (216/389). In women aged less than 50 yr, HPV16 and 18 comprised 32.1% (224/697, p < 0.0001), while HPV 52, 58 and 33 represented 47.9% (334/697, p = 0.02). The distribution of HPV genotypes was compared with previously reported findings for Taiwanese women with cervical cancer (CC). The overall HPV16 positivity rate was significantly higher in CC than in CIN 2/3 (odds ratio: 2.14, 95% CI: 1.91-2.40). In addition, HPV18, 39 and 45 were significantly overrepresented in CC, whereas HPV52, 58, 33, 31, 35, 51 and 53 were underrepresented. We concluded that an effective vaccine against the most common HPV types could prevent a significant proportion of cervical cancer cases that occur in Taiwan.

Prevalence of human papillomavirus genotypes in northern Taiwanese women

The prevalence of Human Papillomavirus (HPV) in the general population of northern Taiwan is described. A total of 343 consecutive cervical swabs from women visiting the medical center for routine gynecologic care were included. Cervical cell cytology was examined by the Papanicolaou (Pap) test, and a PCR-based hybridization gene chip analysis was used to identify HPV genotypes. The HPV prevalence in the overall population was 32.4%. When divided into two groups according to cytology, 20.9% of women with normal cytology were HPV positive while 75.3% of women with abnormal cytology were HPV positive. Among positive samples, 68.5% were single type infections while 31.5% harbored multiple HPV types. A total of 32 types of HPV were identified; the leading five were HPV16 (5.8%), HPV58 (5.3%), HPV53 (4.1%), HPV52 (3.8%), and HPV18 (2.3%). Our results constitute baseline data and may provide important implications for future prophylactic programs. The relatively high prevalence of HPV 58, 53, and 52 among northern Taiwanese women has important implications for vaccine development.

Unique variants of human papillomavirus genotypes 52 and 58 and risk of cervical neoplasia

Human papillomavirus (HPV) 52 and 58 are oncogenic HPV types prevalent in Asia. Our study aims to explore intratypic variants of HPV 52 and 58 in Taiwan. A total of 11,923 women were enrolled from seven townships in 1991-1992. HPV DNA in their cervical cells was detected and typed by EasyChip® HPV blot. Among 424 participants infected with HPV 52 and/or 58, nucleotide variations were determined in cervical cell samples of 406 participants by the polymerase chain reaction sequencing of the long control region, E6 and E7 genes. Nonprototype-like variants including lineages B and C were detected in 278 (99.3%) of 280 HPV 52 samples. The prototype and prototype-like group (lineage A) of HPV58 was found in 132 (98.5%) of 134 HPV 58 samples, with sublineage A1, A2 and A3 variant in 14.2, 27.6 and 56.7%, respectively. Among women infected with single HPV 52 type, the C variant (vs. B variant) was associated with an increased prevalence of cytologically diagnosed high-grade squamous intraepithelial lesion or worse lesions showing an age-adjusted odds ratio (95% confidence interval, CI) of 5.2 (1.0-27.6) and an increased prevalence of histologically confirmed high-grade cervical intraepithelial neoplasia or more severe lesions with an age-adjusted odds ratio (95% CI) of 7.6 (1.3-43.8). It was concluded that frequency distributions of HPV 52 and 58 variants in Taiwan were different from those in European and American populations. The association between C variant of HPV 52 and prevalence of cervical neoplasia needs further validation.

Type-specific human papillomavirus oncogene messenger RNA levels correlate with the severity of cervical neoplasia

This study aimed to evaluate whether quantitation of high-risk human papillomavirus (HR-HPV) E6 messenger RNA (mRNA) can be a potential biomarker for detecting the severity of cervical lesions. HPV genotyping was performed using a modified MY11/GP6+ PCR for HPV DNA amplification, followed by HPV genotype-specific hybridization with on a gene chip. E6 type-specific PCR was used to validate multiple infections. Quantitative real-time reverse transcriptase (QRT-PCR) and real-time PCR used to measure mRNA levels and DNA viral loads of 6 HPV oncogenic types (HPV 16, 18, 31, 33, 52 and 58) in 720 liquid-based cytology samples. The HPV DNA and RNA measurements were correlated with cervical lesions diagnosed by histopathologic examination. mRNA transcripts in the 6 types HPV DNA-positive cases was lower in normal women and <CIN 1 (23%), women with CIN 1 (54%), CIN2+ (77%) and CIN3+ (80%) (p < 0.001). Geometric mean mRNA levels ranged from 24.5 (copies per 50 ng total RNA) in normal women and <CIN 1 to 210.8 in those with CIN 1, 629.0 in CIN2+ and 699.0 in CIN3+ (p < 0.0001). Trends of increasing viral mRNA with severity of histopathologic diagnosis were significant for HPV 16, 18, 52 and 58 transcripts but not for HPV 31 and 33 transcripts. However, geometric mean DNA viral loads of HPV 16, 18, 52 and 58 DNA did not significantly increase with the severity of cervical dysplasia. Therefore, quantitative HPV E6 mRNA levels of high-risk HPV types are potentially useful biomarkers for distinguishing among HPV infections, cervical precancerous lesions and cancer.

Clinical effect of human papillomavirus genotypes in patients with cervical cancer undergoing primary radiotherapy

PURPOSE

To study the prognostic value of the human papillomavirus (HPV) genotypes in cervical cancer patients undergoing radiotherapy.

PATIENTS AND METHODS

A total of 1,010 patients with cervical cancer after radiotherapy between 1993 and 2000 were eligible for this study. The HPV genotypes were determined by a genechip, which detects 38 types of HPV. The patient characteristics and treatment outcomes were analyzed using the Cox regression hazard model and classification and regression tree decision tree method.

RESULTS

A total of 25 genotypes of HPV were detected in 992 specimens (98.2%). The leading 8 types were HPV16, 58, 18, 33, 52, 39, 31, and 45. These types belong to two high-risk HPV species: alpha-7 (HPV18, 39, 45) and alpha-9 (HPV16, 31, 33, 52, 58). Three HPV-based risk groups, which were independent of established prognostic factors, such as International Federation of Gynecology and Obstetrics stage, age, pathologic features, squamous cell carcinoma antigen, and lymph node metastasis, were associated with the survival outcomes. The high-risk group consisted of the patients without HPV infection or the ones infected with the alpha-7 species only. Patients co-infected with the alpha-7 and alpha-9 species belonged to the medium-risk group, and the others were included in the low-risk group.

CONCLUSION

The results of the present study have confirmed the prognostic value of HPV genotypes in cervical cancer treated with radiotherapy. The different effect of the alpha-7 and alpha-9 species on the radiation response deserves additional exploration.

Phylogeographic analysis of human papillomavirus 58

Human papillomavirus 58 (HPV58) is one type of HPV with high risk of causing cervical cancer. Unusually high prevalence of HPV58 has been reported in Asia, Africa and some other areas. However, due to the scattered distribution of global data, in addition to the lack of data of some HPV58 high-incidence nations and regions, like Mainland China, a comprehensive analysis of the global geographical distribution of HPV58 remains blank so far. In this study, HPV58 from the human cervical cancer tissue was detected in Mainland China, and 14 new HPV58-E6/L1 gene sequences were obtained. Moreover, phylogeographic analysis has been conducted combining the HPV58 sequences that have been deposited in GenBank since 1985. The study result shows that the sequences detected from the Shanghai, Jiangsu and Sichuan areas are homologous with those found in the past from Hong Kong and Xi'an, China, as well as Japan and other Southeast Asian areas. Furthermore, Western Africa is considered to be the "root" source of the HPV58 variant, while Mainland China and Southeast Asia are "transit points" and the new sources of HPV58 after receiving the isolates from the "root" source; like HPV16 and HPV18, the HPV58 might also be one of the major HPV types associated with the development and spread of cervical cancer.

A systematic review of the prevalence and attribution of human papillomavirus types among cervical, vaginal, and vulvar precancers and cancers in the United States

OBJECTIVES

To describe prevalence and estimated attribution of human papillomavirus (HPV) types in U.S. cervical, vaginal, and vulvar precancers and cancers.

METHODS

U.S. studies reporting HPV typing for cervical intraepithelial neoplasia (CIN), vulvar intraepithelial neoplasia (VIN), and vaginal intraepithelial neoplasia (VaIN) and/or invasive cancers of those sites were gathered from the PubMed database (http://www.ncbi.nlm.nih.gov/sites/entrez/). Selected studies had PCR testing data for > or =10 cases for a disease endpoint. Analytic methods augmented prior reviews of cervical disease with an updated and expanded analysis (including vulvar and vaginal disease), new selection criteria for specimens, and adjustment for histologic type, where possible, among pooled cancer cases. In addition, for analyses of estimated attribution of HPV types, we incorporated accounting methods for lesions infected with multiple HPV types.

RESULTS

Data from 22 U.S. studies meeting review eligibility criteria were tabulated. Following adjustment for the presence of multiple HPV types in a single specimen, the top two HPV types contributing to disease were CIN 1 (HPV 16/66; 15.3%), CIN 2/3 (HPV 16/31; 61.9%), cervical cancer (HPV 16/18; 79.2%), VIN 1 (HPV 6/11; 41.7%), VIN 3 (HPV 16/18; 84.0%), vulvar cancer (HPV 16/33; 55.5%), VaIN 3 (HPV 16/18; 65.1%), and vaginal cancer (HPV 16/18; 72.7%).

CONCLUSIONS

The HPV type distribution and proportion of cases testing positive for any HPV type were observed to vary among U.S. cervical, vulvar, and vaginal neoplasias and by grade of disease. Adjustment for the presence of multitype HPV infections can have an important effect on the estimated attribution of HPV types to disease, particularly for types other than HPV 16.

Clinical trial experience with prophylactic HPV 6/11/16/18 VLP vaccine in young women from the Asia-Pacific region

OBJECTIVE

To evaluate results of three phase 3 clinical trials of quadrivalent HPV 6/11/16/18 vaccination of young Asia-Pacific women.

METHODS

A total of 814 women from the Asia-Pacific region (aged 16 to 26 years) received vaccine or placebo in 1 of 3 protocols. Descriptive analyses focused on the efficacy, safety, and immunogenicity of the vaccine and the natural history of HPV disease.

RESULTS

Vaccine efficacy against disease caused by HPV types 6, 11, 16, or 18 was 100% for cervical intraepithelial neoplasia (0 vs 12 cases; 95% confidence interval [CI], 63.1%-100%) and 100% for vulvar and vaginal intraepithelial neoplasia or condylomata accuminata (0 vs 5 cases; 95% CI, -11.8% to 100%). The vaccination was highly immunogenic. Vaccine recipients experienced a significantly higher injection site adverse event rate (P=0.002). Compared with other world regions, lower rates of smoking and baseline positivity to 14 HPV types (including the vaccine types) were observed among Asia-Pacific participants.

CONCLUSION

Prophylactic quadrivalent HPV 6/11/16/18 vaccination of young Asia-Pacific women demonstrated high efficacy, safety, and tolerability. Together with an observed low baseline HPV positivity rate, the Asia-pacific population is potentially an important cohort to benefit from vaccination.