Human Papillomavirus Infection and Cervical Cancer Prevention in Japan and Korea

Are HPV-negative lesions concerned for the introduction of primary HPV testing for cervical cancer screening in Japan?

AIM

In Japan, primary human papilloma virus (HPV) testing has not been introduced for cervical cancer screening due to concerns that HPV-negative lesions may be missed and a lack of Japanese data. The purpose of this study was to evaluate the validity of primary HPV testing in Japan by analyzing cervical intraepithelial neoplasia 2 (CIN2) or more/high-risk HPV- (CIN2+/hrHPV-) cases in cervical cancer screening.

METHODS

Data from 35 525 cervical cancer screenings with HPV testing and cervical cytology from 2011 to 2019 in Saga City, Japan, were reviewed. The cases with low-grade squamous intraepithelial lesion (LSIL+)/hrHPV- were analyzed in detail.

RESULTS

The results of the 35 525 examinees were as follows: 31 123 were negative for intraepithelial lesion or malignancy (NILM)/hrHPV-, 2612 were NILM/hrHPV+, 262 were atypical squamous cells of undetermined significance (ASC-US)/hrHPV-, 213 were ASC-US/hrHPV+, 291 were LSIL+/hrHPV-, and 1024 were LSIL+/hrHPV+. Of the 256 LSIL+/hrHPV- examinees for whom histology was available, CIN2+ were CIN2 9.4% (24/256), CIN3 3.9% (10/256), cervical adenocarcinoma 0.4% (1/256), uterine corpus cancer 1.2% (3/256), and uterine sarcoma 0.4% (1/256). Overall, the rate of LSIL+/hrHPV- was 0.82% (291/35.525), 0.1% (36/35525) of which were cervical lesions with CIN2+. Only one cervical adenocarcinoma was detected, but gastric-type adenocarcinoma was not included.

CONCLUSION

HPV-negative CIN2+ or cervical adenocarcinoma is not a concern for the introduction of primary HPV screening in Japan. Primary HPV testing in cervical cancer screening is considered a feasible method that can be used in Japan, although an algorithm suitable for Japan and a national-level management system need to be established.

Factors Affecting the Cervical Cancer Screening Behaviors of Japanese Women in Their 20s and 30s Using a Health Belief Model: A Cross-Sectional Study

In recent years, the incidence and mortality rates of cervical cancer (CC) have increased among young women. Cervical cancer screening (CCS) is crucial to reducing the incidence and mortality of CC in a country such as Japan, where it is challenging to raise HPV vaccination rates. The purpose of this study was to identify psychological and personal characteristics relating to CCS participation among young people by using the Health Belief Model (HBM). For this cross-sectional study, an internet survey was conducted between February–March 2018. Based on HBM and personal characteristics, χ2 tests and logistic analyses were used to identify factors influencing CCS. Responses obtained from 816 women in their 20s and 30s were used in the analysis. For HBM-based psychological characteristics, the odds ratios were significantly higher for “cues to participation in screening” and “barriers to participation at the time of cancer screening”, while “barriers to participation before cancer screening” showed significantly lower odds ratios. On the other hand, it was found that the presence of children and having regular health checkups affected the attributes of screening that were significant for decision-making. Therefore, it is important to create proactive measures to encourage younger women to undergo medical examinations.

Updated clinical guideline for human papillomavirus vaccine: the Korean Society of Gynecologic Oncology guidelines

Since the human papillomavirus (HPV) vaccine guidelines were developed by the Korean Society of Gynecologic Oncology (KSGO) in 2011, 2016, and 2019, several recent studies on the efficacy and safety of HPV vaccines in middle-aged women and men have been reported. Furthermore, there has been an ongoing debate regarding the efficacy of the HPV vaccine in women with prior HPV infection or who have undergone conization for cervical intraepithelial neoplasia (CIN). We searched and reviewed studies on the efficacy and safety of the HPV vaccine in middle-aged women and men and the efficacy of the HPV vaccine in patients infected with HPV and those who underwent conization for CIN. The KSGO updated their guidelines based on the results of the studies included in this review.

Human papillomavirus detected in sperm of Japanese infertile males affects reproductive parameters

OBJECTIVES

The effects of human papillomavirus (HPV) infection on male reproductive parameters are currently a matter of controversy. In order to clarify the issue in Japanese infertile men, the prevalence and localization of HPV in semen, sperm parameters, and superoxide dismutase (SOD) activity in seminal plasma were examined in 216 Japanese infertile men.

METHODS

DNA was extracted from liquid-based cytological semen samples. The β-globin gene was amplified by polymerase chain reaction (PCR), and HPV-DNA was amplified using nested PCR with MY09/MY11 as outer primers and GP5+/GP6+ as inner primers. HPV genotyping was performed in the HPV-positive samples. In addition, SOD levels in seminal plasma were analysed quantitatively. In-situ hybridization (ISH) was performed to localize HPV-DNA in sperm from HPV-positive samples.

RESULTS

Any-risk and high-risk prevalence rates of HPV in semen were 12.5% and 6.9%, respectively. No significant difference in the prevalence of HPV was observed between azoospermic and non-azoospermic subjects. Among non-azoospermic patients, those with HPV detected in semen had significantly lower sperm motility and concentration compared with subjects without HPV detected in semen. SOD levels in seminal plasma were significantly higher in HPV-positive patients compared with HPV-negative patients. ISH analysis of HPV-positive samples revealed that HPV-DNA was localized to the head and mid-piece of sperm. HPV-DNA was present in the sperm of young infertile men.

CONCLUSION

HPV infection of sperm was associated with reduced sperm motility and concentration, and resulted in an increase in seminal SOD activity.

Cross-neutralizing antibody titres against non-vaccine types induced by a recombinant trivalent HPV vaccine (16/18/58) in rhesus macaques

Human papillomavirus (HPV) causes not only most cervical cancers but also cancers of the vagina, vulva, penis, anus, rectum, and oropharynx. Every year, 200,000 women die of cervical cancer in the world, and China accounts for about 10%. HPV vaccines are effective in preventing HPV infections thus HPV-related cancers worldwide. Studies on the clinical trials of the 2v Cervarix™ and the 4v Gardasil® have suggested that immunization with either of these vaccines provided some level of protection against other HPV types that are closely related to the types contained in the vaccines. Here we conducted a preliminary evaluation on the ability to induce cross-neutralizing antibodies in rhesus monkeys by a 3v HPV vaccine that targets HPV16, 18, and 58 and it is specifically designed for Chinese women. We found that this vaccine is no less than Gardasil® in terms of the ability to induce NAbs against non-vaccine types of HPV in rhesus macaques. These results provided evidence from the immunogenicity point of view that the KLWS 3v HPV vaccine is a strong competitor to the imported 2v and 4v HPV vaccines currently available on the market.

Comparison of ThinPrep Integrated Imager-Assisted Screening versus Manual Screening of ThinPrep Liquid-Based Cytology Specimens

OBJECTIVE

The aim of this study was to find out whether ThinPrep Integrated Imager (Hologic Inc.) screening is non-inferior to manual screening in the detection of cervical lesion.

STUDY DESIGN

For a total of 4,011 ThinPrep Pap test specimens stained by ThinPrep staining, manual screening (Manual arm) and ThinPrep Integrated Imager screening (Imager arm) were performed so as not to be screened by the same cytotechnologist, and the sensitivity and specificity in the detection of cervical lesion were compared using McNemar's test.

RESULTS

The sensitivity to detect CIN1 or more squamous cell abnormalities or glandular abnormalities was 91.67% (= 374/408, 95% confidence interval [CI]: 88.44-94.08%) for the Manual arm and 92.40% (= 377/408, 95% CI: 89.28-94.70%) for the Imager arm, and the specificity was 88.87% (= 3,113/3,503, 95% CI: 87.77-89.88%) for the Manual arm and 89.55% (= 3,137/3,503, 95% CI: 88.48-90.54%) for the Imager arm. The differences in sensitivity and in specificity, respectively, were 0.74% (95% CI: -3.14-4.61%, McNemar's test, p = 0.8041) and 0.69% (95% CI: -0.13-1.50%, McNemar's test, p = 0.1125). About the equality of sensitivity and specificity between the 2 methods, 95% CIs of the difference between sensitivity and specificity are in the clinical equivalence range of ±5%, so the Imager arm is non-inferior to the Manual arm.

CONCLUSION

The Imager arm was confirmed to have an equivalent and non-inferior capacity in the detection of cervical lesions compared with the Manual arm, suggesting that its practical application in cervical cytology tests is highly possible.

What Has Changed Since the Introduction of Human Papillomavirus Testing with the Cytology-Based Cervical Cancer Screening System in Japan A Social Experiment

BACKGROUND

Uterine cervical cancer is the fourth most common female cancer in the world. In Japan, we have an apparently low rate of joining cervical cancer screening programs compared with Western countries. Furthermore, the incidence and mortality rate of cervical cancer among the younger generation has been increasing.

OBJECT

The aim of this study was to assess the effectiveness of cervical cancer screening with human papillomavirus (HPV) testing and cytology in Japan.

METHODS

Collaborating with Saga City government, we initiated a cervical cancer screening system consisting of HPV testing and baseline cervical cytology from April 2011 as a social experiment. A total of 17,284 participants have been screened with this new combination system.

RESULTS

After HPV testing with cytology-based cervical cancer screening, the number of screenings done in women aged under 40 years has significantly increased. In addition, the number of women diagnosed with cervical intraepithelial neoplasia grade 3 has increased (25 of 14,025 vs. 146 of 23,049 under 50 years: p < 0.001).

CONCLUSION

These data suggested that the introduction of HPV testing with cytology-based cervical cancer screening as an adjunct to conventional cytology resulted in better efficiency and more accurate screening among the Japanese population.

Clinical guideline for 9-valent HPV vaccine: Korean Society of Gynecologic Oncology Guideline

In 2016, 9-valent human papillomavirus (HPV) vaccine has been newly introduced in Korea, thus the need to develop recommendations for the vaccine has raised. Until we decide to develop a guideline, no further studies on the bi-valent or quadri-valent HPV vaccine have been announced. We searched and reviewed the literatures focused on the efficacy of 9-valent HPV vaccine, the ideal age of 3-dose schedule vaccination, the efficacy of 9-valent HPV vaccine in middle-aged women, the efficacy of the 2-dose schedule vaccination, the safety of 9-valent HPV vaccine, the possibility of additional 9-valent HPV vaccination, and cross-vaccination of 9-valent HPV vaccine. So, Korean Society of Gynecologic Oncology (KSGO) developed a guideline only for 9-valent HPV vaccine.

Factors associated with cervical cancer screening among young unmarried Japanese women: results from an internet-based survey

BACKGROUND

The prevalence of cervical cancer among women aged 20-30 years has been increasing. A better understanding of the factors correlated with cervical cancer screening is vital to better identify suitable candidates and develop effective interventions. However, few studies have examined factors correlated with cervical cancer screening using a quantitative research design. Thus, this study aimed to assess the prevalence of and factors correlated with cervical cancer screening among unmarried and sexually active Japanese women aged 20-29 years.

METHODS

Seven hundred Japanese women who responded to an internet-based cross-sectional survey conducted by a marketing research company in 2015 were enrolled. Associations between lifetime cervical cancer screening and demographic profile, sexual behavior, and psychosocial factors were assessed via univariate analysis. Variables indicating significance (P < 0.05) were used in the univariate analysis to determine adjusted odds ratios (AOR).

RESULTS

Overall, 383 (54.7%) respondents underwent cervical cancer screening during their lifetime. Multiple regression analysis indicated that age, employment status, income, lifetime number of sex partners, human papillomavirus (HPV) vaccination, receipt of a free coupon for cervical cancer screening from the local government, perceived susceptibility and logistical barriers (cost/time), and confidence of receiving Pap testing from a male physician were significantly correlated with lifetime cervical cancer screening. Individuals aged 28-29 years (AOR = 1.86) and those with full-time employment (AOR = 3.30), income ≥ ¥ 4,000,000($35,000) (AOR = 1.60), > 5 lifetime sex partners (AOR = 1.97), HPV vaccination (AOR = 4.88), coupon from the local government (AOR = 3.14), higher perceived level of cervical cancer susceptibility (middle, AOR = 1.77; high, AOR = 3.23), lower perceived logistical barriers (middle, AOR = 0.55; high, AOR = 0.31), and higher confidence of receiving pap testing from a male physician (AOR = 2.66) were more likely to undergo cervical cancer screening.

CONCLUSIONS

Women who were younger and unemployed and those with lower perceived cervical cancer susceptibility, higher perceived logistical barriers, and lower confidence of receiving Pap testing from a male physician were less likely to undergo lifetime cervical cancer screening. Thus, to increase the cervical cancer screening rate among young women, it may be effective to target younger unemployed women, provide interventions to increase perceived susceptibility, and recommend tests while considering psychosocial barriers.

Factors influencing behavioral intention to undergo Papanicolaou testing in early adulthood: Comparison of Japanese and Korean women

In this study, we identified the factors influencing behavioral intention to undergo Papanicolaou testing among Japanese and Korean women in early adulthood. Their behavioral intentions were compared in this cross-sectional descriptive study. In total, 887 women (Japanese = 498, Korean = 389) aged 20-39 years participated in this study. Using a self-report questionnaire, knowledge, attitudes, subjective norm, perceived behavioral control, and behavioral intention were surveyed. There were significant differences between Japanese and Korean women's scores on all main variables. For Japanese women, all the variables moderately correlated with behavioral intention. In comparison, for Korean women, all independent variables, except for knowledge, moderately correlated with behavioral intention. Through a multiple regression analysis, age, undergoing Papanicolaou testing, attitudes, subjective norm, and perceived behavioral control were identified as significant predictors of behavioral intention among Japanese women. Among Korean women, job status, undergoing a Papanicolaou test, attitudes, subjective norm, and perceived behavioral control were demonstrated as significant predictors of behavioral intention. Health professionals should consider these factors to encourage Papanicolaou testing in women in early adulthood.

Preventive vaccination against cervical cancer: Korean Society of Gynecologic Oncology Guideline

After human papillomavirus (HPV) vaccine guidelines published by Korean Society of Gynecologic Oncology (KSGO) in 2011, new studies have been published, leading to additional data regarding efficacy, safety, number of vaccination rounds, and ideal age of vaccine administration. We searched and reviewed the literatures focused on the efficacy of 2-dose schedule vaccination, the efficacy of 3-dose schedule vaccination in middle-aged women, the ideal age of 3-dose schedule vaccination, the safety of HPV preventive vaccine, and the ability of cross-protection of each HPV preventive vaccine. The KSGO has revised the previous guideline based on the results of the above studies.

Challenges in breast and cervical cancer control in Japan

Since the mid-1990s, there has been an increasing incidence of, and mortality from, cervical and breast cancers in Japan. Such an increase has raised concerns over the efficiency of Japan's screening programmes for these cancers. Although citizens benefit from universal health coverage, the Japanese health insurance system mostly focuses on tertiary prevention and disease treatment, while secondary prevention (screening) is low priority. Citizens have multiple opportunities to be screened for cancer-either through programmes organised by municipalities, or individual or collective, opportunistic and comprehensive health check-ups on a voluntary basis. Despite this, however, participation is as low as 35% of the target population for both cancers. In this Policy Review, we discuss the challenges in the prevention of breast and cervical cancers in Japan, particularly focusing on the structure of the National Health Insurance system and the National Cancer Control Plan, reasons for low participation as a result of social and political attitudes, as well as providing recommendations to overcome these challenges. Japanese women would benefit from new measures to increase participation, a national data surveillance programme to monitor screening activities, and the implementation of a quality assurance system among all providers.

The cultural context of teaching and learning sexual health care examinations in Japan: a mixed methods case study assessing the use of standardized patient instructors among Japanese family physician trainees of the Shizuoka Family Medicine Program

BACKGROUND

In contrast to many western nations where family medicine is a cornerstone of the primary care workforce, in Japan the specialty is still developing. A number of services within the bailiwick of family medicine have yet to be fully incorporated into Japanese family medicine training programs, especially those associated with sexual health. This gap constitutes a lost opportunity for addressing sexual health-related conditions, including cancer prevention, diagnosis, and treatment. In this mixed methods case study we investigated the perceived acceptability and impact of a standardized patient instructor (SPI) program that trained Japanese family medicine residents in female breast, pelvic, male genital, and prostate examinations.

CASE DESCRIPTION

Building on an existing partnership between the University of Michigan, USA, and the Shizuoka Family Medicine Program, Japan, Japanese family medicine residents received SPI-based training in female breast, pelvic, male genital, and prostate examinations at the University of Michigan. A mixed methods case study targeting residents, trainers, and staff was employed using post-training feedback, semi-structured interviews, and web-based questionnaire.

DISCUSSION AND EVALUATION

Residents' and SPIs' perceptions of the training were universally positive, with SPIs observing a positive effect on residents' knowledge, confidence, and skill. SPIs found specific instruction-related approaches to be particularly helpful, such as the positioning of the interpreter and the timing of interpreter use. SPIs provided an important opportunity for residents to learn about the patient's perspective and to practice newly learned skills. Respondents noted a general preference for gender concordance when providing gender-specific health care; also noted were too few opportunities to practice skills after returning to Japan. For cultural reasons, both residents and staff deemed it would be difficult to implement a similar SPI-based program within Japan.

CONCLUSIONS

While the SPI program was perceived favorably, without sufficient practice and supervision the skills acquired by residents during the training may not be fully retained. Deep-rooted taboos surrounding gender-specific health care appear to be a significant barrier preventing experimentation with SPI-based sexual health training in Japan. The feasibility of implementing a similar training program within Japan remains uncertain. More research is needed to understand challenges and how they can be overcome.

Efficacy of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine against cervical intraepithelial neoplasia and cervical infection in young Japanese women

In this open, extended follow-up study (NCT00929526, Clinicaltrials.gov), we evaluated the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine efficacy, immunogenicity and safety up to 4 years after first vaccination in Japanese women aged 20–25 years. In the initial randomized, double-blind study (NCT00316693), 1040 women received the study vaccine or hepatitis A control vaccine; 752 women were included in the follow-up study. In women from the according-to-protocol efficacy cohort (ATP-E), who were initially seronegative for the HPV type analyzed, no cervical intraepithelial neoplasia (CIN) grade 1 or greater (CIN1+) cases associated with HPV-16/18 were reported in the HPV group, while in the control group, 5 cases were identified in extended follow-up analyses (vaccine efficacy [VE] 100% [95% CI: −3.7–100]) and 8 cases in combined initial and follow-up studies analyses (VE 100% [42.2–100]). In the ATP-E, VE against CIN1+ and CIN2+ associated with high-risk HPV types reached 66.4% (21.6–87.1) and 83.0% (22.1–98.2) in extended follow-up analyses, and 63.4% (28.8–82.3) and 77.3% (30.4–94.4) in analyses of combined studies, respectively. During the 4-year period, protection against CIN1+ and CIN2+, irrespective of the HPV type, was 56.7% (32.8–72.6) and 54.9% (20.5–75.3) in women receiving ≥1 vaccine dose, regardless of baseline serostatus (total vaccinated cohort [TVC]) and 61.0% (11.8–84.2) and 73.9% (1.1–95.3) in women naïve to HPV infection at baseline (TVC-naïve), respectively. The high VE observed in Japanese women, accompanied by a sustained immune response and a clinically acceptable safety profile, support findings of large, international trials.

Cost-effectiveness of a bivalent human papillomavirus vaccination program in Japan

Background Human papillomavirus (HPV) vaccines and their widespread adoption have the potential to relieve a large part of the burden of cervical cancer morbidity and mortality, particularly in countries that have low screening rates or, like Japan, lack a cohesive universal screening program. An economic evaluation was conducted to assess the cost-effectiveness of introducing a bivalent HPV vaccination program in Japan from a healthcare perspective. Methods: A Markov model of the natural history of HPV infection that incorporates both vaccination and screening was developed for Japan. The modelled intervention, a bivalent HPV vaccine with a 100% lifetime vaccine efficacy and 80% vaccine coverage, given to a cohort of 12-year-old Japanese girls in conjunction with the current screening program, was compared with screening alone in terms of costs and effectiveness. A discount rate of 5% was applied to both costs and utilities where relevant. Results: Vaccination alongside screening compared with screening alone is associated with an incremental cost-effectiveness ratio (ICER) of US$20 315 per quality-adjusted-life-year gained if 80% coverage is assumed. The ICER at 5% coverage with the vaccine plus screening, compared with screening alone, is US$1158. Conclusion: The cost-effectiveness results suggest that the addition of a HPV vaccination program to Japan’s cervical cancer screening program is highly likely to prove a cost-effective way to reduce the burden of cervical cancer, precancerous lesions and HPV16/18-related diseases.

Human papillomavirus genotype distribution in cervical intraepithelial neoplasia grade 2/3 and invasive cervical cancer in Japanese women

OBJECTIVE

Human papillomavirus vaccines are being introduced worldwide and are expected to reduce the incidence of cervical cancer. Here we report a cross-sectional study using a validated human papillomavirus genotyping method to reveal the human papillomavirus prevalence and genotype distribution in Japanese women with cervical intraepithelial neoplasia Grade 2/3 and invasive cervical cancer.

METHODS

Cervical exfoliated cells were collected from 647 patients with abnormal cervical histology (cervical intraepithelial neoplasia Grade 2, n = 164; cervical intraepithelial neoplasia Grade 3, n = 334; and invasive cervical cancer, n = 149), and subjected to the PGMY-PCR-based genotyping assay. The association between human papillomavirus infection and lesion severity was calculated using a prevalence ratio.

RESULTS

Overall, the prevalence of human papillomavirus deoxyribonucleic acid was 96.3% in cervical intraepithelial neoplasia Grade 2, 98.8% in cervical intraepithelial neoplasia Grade 3 and 88.0% in invasive cervical cancer (97.8% in squamous cell carcinoma and 71.4% in adenocarcinoma). The three most prevalent types were as follows: human papillomavirus 16 (29.3%), human papillomavirus 52 (27.4%) and human papillomavirus 58 (22.0%) in cervical intraepithelial neoplasia Grade 2; human papillomavirus 16 (44.9%), human papillomavirus 52 (26.0%) and human papillomavirus 58 (17.4%) in cervical intraepithelial neoplasia Grade 3; and human papillomavirus 16 (47.7%), human papillomavirus 18 (23.5%) and human papillomavirus 52 (8.7%) in invasive cervical cancer. The prevalence ratio of human papillomavirus 16 was significantly higher in cervical intraepithelial neoplasia Grade 3 compared with cervical intraepithelial neoplasia Grade 2 (prevalence ratio, 1.62; 95% confidence interval, 1.26-2.13) and in squamous cell carcinoma compared with cervical intraepithelial neoplasia Grade 3 (prevalence ratio, 1.55; 95% confidence interval, 1.25-1.87). Multiple infections decreased from cervical intraepithelial neoplasia Grade 2/3 (38.4/29.6%) to invasive cervical cancer (14.1%), whereas co-infections with human papillomavirus 16/52/58 were found in cervical intraepithelial neoplasia Grade 2/3.

CONCLUSIONS

The results of this study provide pre-vaccination era baseline data on human papillomavirus type distribution in Japanese women and serve as a reliable basis for monitoring the future impact of human papillomavirus vaccination in Japan.

Baseline prevalence and type distribution of human papillomavirus in healthy Chinese women aged 18-25 years enrolled in a clinical trial

Baseline human papillomavirus (HPV) prevalence and type distribution were evaluated in young Chinese women enrolled in a clinical trial of an HPV vaccine (ClinicalTrials.gov registration NCT00779766). Cervical specimens and blood samples were collected at baseline from women aged 18–25 years (n = 6,051) from four sites across Jiangsu province. Cervical specimens were tested for HPV DNA by SPF₁₀ PCR-DEIA-LiPA₂₅ version 1, and HPV-16/18 type-specific polymerase chain reaction. Anti-HPV-16 and anti-HPV-18 antibody titres were quantified by enzyme-linked immunosorbent assay. At baseline, 15.3% of women were DNA positive for any of 14 HPV high-risk (hr) types (HPV-16/18/31/33/35/39/45/51/52/56/58/59/66/68). The most commonly detected hrHPV types in cervical specimens were HPV-52 (4.0%) and HPV-16 (3.7%). High-risk HPV DNA-positivity increased with severity of cytological abnormalities: 39.3% in atypical squamous cells of undetermined significance, 85.0% in low-grade squamous intraepithelial lesions and 97.8% in high-grade squamous intraepithelial lesions (HSIL). The hrHPV types most frequently detected in HSIL were HPV-16 (63.0%), HPV-18 (17.4%), HPV-52 (17.4%), HPV-58 (15.2%) and HPV-33 (15.2%). The hrHPV types most frequently detected in cervical intraepithelial neoplasia 2+ were HPV-16 (66.1%), HPV-33 (16.1%), HPV-52 (16.1%), HPV-58 (14.5%) and HPV-51 (11.3%). Multiple hrHPV infections were reported for 24.4% of hrHPV DNA positive women. Regardless of baseline HPV DNA status, 30.5% and 16.0% of subjects were initially seropositive for anti-HPV-16 and anti-HPV-18, respectively. In conclusion, the high baseline seropositivity rate and intermediate prevalence of cervical hrHPV types in Chinese women aged 18–25 years underlines the importance of early HPV vaccination in this population.

Comparison of the performance of the NucliSENS EasyQ HPV E6/E7 mRNA assay and HPV DNA chip for testing squamous cell lesions of the uterine cervix

This study aims to evaluate the clinical performance of the NucliSENS EasyQ assay and compare it with HPV DNA genotyping for the detection of high-grade squamous intraepithelial lesions (HSIL) and cancer in a Korean population. In 188 total thin prep samples, the remaining fluid after cytology slide preparation was tested with Goodgene HPV DNA chips and the NucliSENS EasyQ HPV E6/E7 messenger RNA (mRNA) assay. The sensitivity and specificity of each test were calculated with HSIL and squamous cell carcinoma (SCC) as the disease endpoint. Out of the 188 samples, 139 (74%) were positive for DNA of 14 HPV types, while 57 (30%) cases were positive for E6/E7 mRNA. The DNA test was positive in cytology cases of SCC, HSIL, and atypical squamous cell. The mRNA test yielded results of 75%, 74%, 60%, 56%, and 29% positivity in abnormal cytology cases of SCC, HSIL, atypical squamous cells - cannot exclude HSIL, atypical squamous cells of undetermined significance, and low-grade squamous intraepithelial lesion, respectively. In normal cytology cases, the positivity rates were 9% and 53% for the mRNA and DNA tests, respectively. For detection of HSIL and SCC, the sensitivity of the mRNA test was 74.36% and that of the DNA test was 100%, while the specificities of the tests were 85% and 40.83%, respectively. These findings suggest that the HPV E6/E7 mRNA assay can overcome the shortcoming of low specificity of DNA assays for clinical detection of high-grade cervical lesions and malignancies.

Effect of human papillomavirus genotype on severity and prognosis of cervical intraepithelial neoplasia

Objective

This study evaluated the effect of the specific human papillomavirus (HPV) genotypes on severity and prognosis in cervical intraepithelial neoplasia (CIN) patients.

Methods

The medical records of 446 patients treated with loop electrosurgical excision procedure (LEEP) were reviewed. The severity of CIN was categorized as CIN1/CIN2 versus CIN3+ including CIN3 and carcinoma in situ (CIS). HPV genotypes were categorized as 1) low risk, 2) intermediate risk, 3) high risk/HPV 16, 4) high risk/HPV 18, and 5) unclassified. Progression was defined as abnormal cytology, including atypical squamous cells, low-grade squamous intraepithelial lesion and high-grade squamous intraepithelial lesion. The margin status and progression free survival (PFS) by HPV genotypes were analyzed in 355 women with three months or more of post-treatment records.

Results

CIN3+ was the most common CIN type (67.7%), and high risk/HPV 16 (26.9%) was the most common genotype. Intermediate risk (P < 0.01), high risk/HPV 16 (P < 0.01) and high risk/HPV 18 (P < 0.01) were significantly more common in women with CIN3+ than CIN1/CIN2. Patients with high risk/HPV 18 showed the highest rate of positive margins (P < 0.01). The margin status proved to be the only statistically significant factor affecting PFS.

Conclusion

The proportion of positive margins was significantly different by HPV genotypes and highest in high risk/HPV 18 group. CIN patients with high risk/HPV 18 need to be more carefully tracked than patients with the other HPV genotypes.

Cervical cancer burden and prevention strategies: Asia Oceania perspective

The Asia Oceania region contributes to more than 50% of cervical cancer cases worldwide. Yet cervical cancer is one of few cancers that can be prevented through comprehensive screening for precancerous lesions, with their subsequent treatment. Screening with cervical cytology, a very old technology, has reduced cervical cancer mortality and incidence when applied in comprehensive programs with high coverage and high quality assurance. However, of those countries within this region that have set up such programs, many have been opportunistic, had poor coverage, or inadequate treatment facilities for lesions found. Consequently, they have not seen large reductions in cancer incidence or mortality. Some have therefore adopted visual inspection by acetic acid (VIA) and Lugol's iodine (VILI) or human papillomavirus (HPV) DNA assays for screening. With two safe, immunogenic and efficacious prophylactic vaccines licensed, the way forward to reduction of cervical cancer to becoming uncommon is within reach. Where governments have supported high coverage public-health vaccination programs, reductions in disease burden with shortest incubation (genital warts, high-grade abnormalities) are already being reported. One of the biggest impediments is the cost of vaccines that are affordable to resource-poor countries. Other challenges include, infrastructure for delivery of vaccines, plus general acceptance of vaccination by the community.

Assessment of the knowledge and attitude of female students towards cervical cancer prevention at an international university in Japan

Cervical cancer resulting from prior infection with human papillomavirus (HPV) is a significant public health threat against young Japanese women. A national immunization plan to vaccinate 13~16 year old female students against HPV infection has been started in Japan since 2010, and may reach almost full coverage by the end of 2012. Older age females who may already be sexually active are not targeted by this plan but should follow safer sex practices as well as periodic screening of the cervix cytology to reduce their risk of developing cervical cancer. HPV vaccination alone does not offer full protection either, because only some HPV types are covered by the vaccines and the long-term efficacy of the vaccines has not been determined yet. Therefore, we did a survey at an international university in Japan to study the knowledge and attitude of female college students towards prevention of cervical cancer, to examine the age when they start sexual activity and other related attributes that may influence the risk of cervical cancer. We discuss the results of our survey and what they imply for the possible impact of an HPV immunization plan on the risk of cervical cancer in Japan, and conclude by an emphasis on the need to increase awareness among Japanese female adolescents and to enhance the cervical screening rates among older females who are already sexually active.

Knowledge about human papillomavirus (HPV), and health beliefs and intention to recommend HPV vaccination for girls and boys among Korean health teachers

The human papillomavirus (HPV) vaccination rate in Korea is very low because a school-based HPV vaccination program has not yet been introduced. This study was designed to assess HPV knowledge, compare the health beliefs toward HPV vaccination and intention to recommend HPV vaccination for girls and boys, and identify the factors influencing the intention to recommend HPV vaccination for girls and boys among Korean health teachers. A descriptive cross-sectional study design was employed, in which 757 health teachers who worked at elementary, middle, high, and special schools in Korea participated via an online survey. A self-administered, structured questionnaire was applied, which included items on sociodemographics, HPV awareness, HPV knowledge, perceived benefits, susceptibility, severity, and barriers toward HPV vaccination for girls and boys, and intention to recommend HPV vaccination for girls and boys. The rate of correct HPV knowledge items ranged from 5.2% to 89.2%; 23.4% of the health teachers answered that they had ever taught about HPV, 97% answered that both boys and girls should receive HPV vaccination, and 47.6% answered that the best time for HPV vaccination is when students are at middle school. There were differences regarding the perceived benefits (Z=-7.69, p<0.001), perceived susceptibility (Z=-3.37, p=0.001), perceived severity (Z=-4.13, p<0.001), and perceived barriers (Z=-4.90, p<0.001) toward HPV vaccination, and regarding intention to recommend HPV vaccination (Z=-15.21, p<0.001) for girls and boys. Factors associated with the intention to recommend HPV vaccination for girls were the HPV vaccination status of the health teachers' children [odds ratio (OR)=4.24, 95% confidence interval (95% CI)=1.14-15.72], and the teachers' Pap-test experience (OR=2.50, 95% CI=1.05-5.91), perceived benefits (OR=3.30, 95% CI=1.26-7.40), perceived susceptibility (OR=3.25, 95% CI=1.58-6.68), and perceived barriers (OR=0.51, 95% CI=0.30-0.99); these factors for boys were the health teachers' career duration (OR=1.61, 95% CI=1.12-2.32), HPV knowledge (OR=1.45, 95% CI=1.01-2.09), perceived benefits (OR=3.46, 95% CI=2.27-5.26), perceived susceptibility (OR=1.55, 95% CI=1.04-2.29), and perceived severity (OR=1.71, 95% CI=1.15-2.56). General awareness of HPV should be increased and more specific information about HPV-including that related to vaccination of boys and men-should be provided for health teachers. Although a school-based HPV vaccine program has yet to be introduced in Korea, health teachers should possess general knowledge about HPV and HPV vaccination, and differences in attitudes and intentions related to HPV vaccination between girls and boys should be reduced.

Liquid-based urine cytology as a tool for detection of human papillomavirus, Mycoplasma spp., and Ureaplasma spp. in men

Liquid-based urine cytology (LB-URC) was evaluated for cytological diagnosis and detection of human papillomavirus (HPV), Mycoplasma, and Ureaplasma. Midstream urine samples were collected from 141 male patients with urethritis and 154 controls without urethritis, and sediment cells were preserved in liquid-based cytology solution. Urethral swabs from urethritis patients were tested for the presence of Neisseria gonorrhoeae and Chlamydia trachomatis. Papanicolaou tests were performed for cytological evaluation. HPV, Mycoplasma, and Ureaplasma genomes were determined by PCR-based methods, and localization of HPV DNA in urothelial cells was examined by in situ hybridization (ISH). The β-globin gene was positive in 97.9% of LB-URC samples from urethritis patients and in 97.4% of control samples, suggesting that high-quality cellular DNA was obtained from the LB-URC samples. HPV DNA was detected in 29 (21.0%) urethritis cases and in five (3.3%) controls (P < 0.05). HPV type 16 (HPV 16) was most commonly found in urethritis patients. Cytological evaluations could be performed for 92.1% of urethritis patients and 64.3% of controls. Morphological changes suggestive of HPV infection were seen in 20.7% of the HPV-positive samples, and ISH demonstrated the presence of HPV DNA in both squamous and urothelial cells in HPV-positive samples. Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum were detected in 14.5%, 10.9%, 6.5%, and 12.3% of urethritis patients, respectively. The prevalence rates of these microorganisms (except Ureaplasma parvum) were significantly higher in urethritis cases than controls (P < 0.05). LB-URC is applicable for detection of HPV, Mycoplasma, and Ureaplasma. HPV infection occurs in urothelial cells, especially in gonococcal urethritis.

Correlation between immunocytochemistry of human papilloma virus L1 capsid protein and behavior of low-grade cervical cytology in Korean women

AIM

The aim of this study was to evaluate the behavior of low-grade squamous intraepithelial lesion (LSIL) in Korean women infected with human papillomavirus (HPV) in relation to the immunocytochemical detection of the HPV L1 capsid protein.

MATERIAL AND METHODS

From January 2006 to December 2007, a total of 353 immunocytochemistry tests were performed on specimens from HPV-infected patients with LSIL. Due to exclusions, the study population was reduced to 318. Subjects were monitored at 4-6 month intervals. The regression, persistence, and progression of the cytologic abnormalities of the 318 cases were compared with the results of HPV L1 capsid protein immunocytochemical detection.

RESULTS

Of the 137 patients negative for the HPV L1 capsid protein, 38 (27.7%) showed progression to high-grade lesions, 50 (36.5%) showed persistence, and 49 (35.8%) showed regression to normal cytological features. In contrast, of the remaining 181 patients positive for the HPV L1 capsid protein, 15 (8.3%) showed progression to high-grade lesions, 74 (40.9%) showed persistence, and 92 (50.8%) showed regression. The results of immunocytochemical testing for the HPV L1 capsid protein show a linear association with the progression or regression behavior of low-grade cervical cytology in patients infected with HPV (linear by linear association test, P<0.05).

CONCLUSION

Immunocytochemical detection of HPV L1 was significantly related with the biological patterns of LSIL in Korean women. Hence, immunocytochemistry for the detection of HPV L1 is beneficial in providing further information for LSIL.

Prevalence and type distribution of human papillomavirus in healthy Japanese women aged 20 to 25 years old enrolled in a clinical study

Efficacy, immunogenicity and tolerability of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine were evaluated in Japanese women aged 20-25 years, for which results have been reported previously. We analyzed the baseline data from that study and report the prevalence rates of HPV infection in young healthy Japanese women. One thousand and the forty Japanese women aged 20-25 years were enrolled in a phase II, double-blind, controlled, randomized, multicenter study. At study entry, cervical specimens were collected from the women and tested by line probe assay for 25 HPV-types and by HPV-16/18-specific polymerase chain reaction. The most frequently detected HPV-type in baseline cervical specimens was HPV-52 (8.1%), followed by HPV-16 (6.5%), HPV-51 (4.5%), HPV-18 (4.0%) and HPV-31 (3.8%). The proportion of HPV DNA-positive women increased with severity of cytological abnormalities: 26.1% (237/908) in normal cytology, 93.3% (70/75) in low-grade squamous intraepithelial lesion and 100% (7/7) in high-grade squamous intraepithelial lesion. The relative contribution of HPV-16 and HPV-18 was 4.1 and 3.0% for normal cytology cases, and 20.0 and 16.0% in low-grade squamous intraepithelial lesion, respectively. HPV-16 was found in four of seven high-grade squamous intraepithelial lesion cases (57.1%) and five of the six cervical intraepithelial neoplasia 2+ cases (83.3%). Multiple and single HPV infections were observed in 13.5% (140/1039) and 20.7% (215/1039) of all women, respectively. The HPV prevalence rates in Japanese women aged 20-25 years underline the importance of HPV vaccination at a young age and this report should be useful for monitoring changes in HPV prevalence after widespread HPV vaccination in Japanese women.

Multinational comparison of diagnostic clues for uterine cervical lesions among cytotechnologists in Asian countries

Vaccination has been underway in several countries for sexually inactive young girls or women against HPV 16 and 18 to prevent them from infection of these HPV types and concurrent cancer development. However, uterine cervical cancers may remain uncontrolled among some Asian countries, where other types of HPV infection are more frequent. A sensitive cancer screening system would remain important for detection of the earlier stage cervical cancers in Asian countries. In this study, 130 cytotechnologists (CTs) in Asian countries (Taiwan 80, Japan 18, Korea 15, Thailand 11, Singapore 3, Bhutan 2, and Mongolia 1) participated in the vote. Selected 10 cervical Pap smears that would be adequate to identify the diagnostic clues especially for atypical squamous cells (ASC) with two or three representative pictures for each case were displayed on the website. The percentages of consistent diagnosis voted by certified CTs with ≥5 years of experience were compared among 10 cervical cases or among Asian countries enrolled. As results, low consistency for ASC cases and high consistency for squamous intraepithelial lesion (SIL) were observed. Examining specimens for the diagnostic clues of ASC in TBS is crucial to maintain the high sensitivity and positive predictive value of SIL in Asian countries.

Vaccination with a human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine in Korean girls aged 10-14 years

The human papillomavirus (HPV)-16/18 AS04-adjuvanted cervical cancer vaccine has been demonstrated to be highly efficacious and immunogenic with a favorable safety profile. This study assessed the immunogenicity and safety of the HPV-16/18 AS04-adjuvanted vaccine in healthy Korean girls aged 10-14 yr. This multi-center, observer-blind trial randomly assigned 321 healthy girls to receive three doses (0, 1, 6-month schedule) of HPV-16/18 AS04-adjuvanted vaccine or hepatitis A vaccine. Immunogenicity against vaccine antigens was assessed one month post-Dose 3. Solicited and unsolicited adverse events (AEs) and serious AEs (SAEs) were recorded. In the according-to-protocol analysis, all initially seronegative subjects vaccinated with the HPV-16/18 AS04-adjuvanted vaccine had seroconverted at Month 7, with a peak geometric mean titer (GMT) that was 600-fold higher than the natural infection titer of 29.8 EU/mL for HPV-16 and a peak GMT that was 400-fold higher than the natural infection titer of 22.6 EU/mL for HPV-18. The vaccine was well tolerated with no increase in reactogenicity with subsequent doses and no reports of vaccine-related SAEs. In conclusion, the HPV-16/18 AS04-adjuvanted vaccine is shown to be highly immunogenic and generally well-tolerated in Korean girls aged 10-14 yr.

Proceedings of the Modeling Evidence in HPV Pre-Conference Workshop in Malmö, Sweden, May 9-10, 2009

BACKGROUND

Prominent published and active human papillomavirus (HPV) modelers from around the world were invited to participate in the inaugural Modeling Evidence in HPV (MEHPV) Pre-Conference Workshop on May 9-10, 2009, in Malmö, Sweden. The workshop took place directly before the 25th International Papillomavirus Conference.

OBJECTIVES

The aim of the workshop was to develop an international network of investigators engaged in HPV modeling and to facilitate open discussion about the structure and parameterization of models, as well as other methodologic concerns.

METHODS

Thirty-four participants from more than a dozen countries and a variety of settings, representing the authors or coauthors of 82% of the HPV modeling literature, exchanged ideas on fundamental questions in the field. These proceedings, based on the 217-page transcript, were assembled by the Scientific Committee to summarize the ideas of workshop participants in a deidentified, readable fashion. They represent the work and recorded opinions of session participants and do not constitute the official positions of participants as a whole or individually, the Scientific Committee, or any sponsoring organization or entity.

RESULTS

In charting a path forward, 3 topics emerged as most pressing: best practices for HPV modeling, comparative modeling, and modeling in developing countries.

CONCLUSION

This summary of the proceedings of the preconference workshop on HPV modeling characterizes many of the prominent contemporary issues in the field.

Trends in socioeconomic disparities in organized and opportunistic gastric cancer screening in Korea (2005-2009)

BACKGROUND

A growth of consensus and increasing activities related to organized cancer screening programs has occurred in Korea since 1999. It is important to assess disparities in the fight against cancer, and it is crucial to identify particular groups that may be experiencing a high burden of cancer-related illness.

METHODS

Data from 8,160 men and women ages >40 years from the 2005 to 2009 Korean National Cancer Screening Survey were used to analyze the relationship between socioeconomic position and receiving upper gastrointestinal series or upper endoscopy within the past 2 years. We used absolute and relative concentration indexes, that is, summary measures of disparity based on both rate differences and rate ratios.

RESULTS

For organized screening, the education disparity declined, but the income disparity index increased, indicating that participation in organized screening was relatively more concentrated among the lower-income groups. For opportunistic screening, income and education disparities increased due to the widening of socioeconomic differences.

CONCLUSIONS

The results of this study suggested progress toward socioeconomic disparity-related goals in organized screening for gastric cancer. However, the income disparity trends in organized screening may change in a manner similar to those in opportunistic screening in the future because of the much faster rate of organized screening uptake by those higher on the socioeconomic scale.

IMPACT

This study addresses the routine monitoring of coverage of screening among different socioeconomic groups and could be used to inform policies to reduce disparity in coverage.

Specific Human Papillomavirus Types and Other Factors on the Risk of Cervical Intraepithelial Neoplasia: A Case-Control Study in Korea

Objective:

Cervical neoplasia is attributed to a persistent human papillomavirus (HPV) infection. We performed a hospital-based, case-control study to evaluate the associations of HPV genotypes and other cofactors with cervical intraepithelial neoplasia (CIN).

Methods:

A total of 158 women were enrolled after we received their informed consent, and the control group (the non-CIN group; n = 80) was selected from women at St Paul's Health Promotion Center. The CIN group (n = 78) was enrolled from the outpatient clinics at Kangnam St Mary's Hospital. Cervical intraepithelial neoplasia was confirmed with colposcopic-guided biopsy or loop electrosurgical excision procedure-conization. A structured questionnaire, Papanicolaou test, and HPV testing were completed. We compared each risk factor using χ2tests and simple logistic regression analysis between the CIN and non-CIN groups. Finally, odds ratios (ORs) were calculated again by multiple logistic regression analysis.

Results:

The most frequent HPV types in CIN were HPV-16, HPV-58, HPV-31/-33, and HPV-35/−56. The OR of the A9 group (HPV-16, HPV-31, HPV-33, HPV-35, HPV-52, HPV-58) was 22.7 (95% confidence interval [CI], 8.3-62.5), that of the A6 group (HPV-53, HPV-56, HPV-66) was 2.9 (95% CI, 1.1-7.5), and that of the A7 group (HPV-18, HPV-39, HPV-45, HPV-59, HPV-68) was 1.5. Sexual debut before 20 years old had significantly higher OR than did a sexual debut after 30 years (OR, 32.9; 95% CI, 2.8-364.7). The OR for CIN in single women versus married women was 6.2 (95% CI, 2.5-15.2). Compared with parous women (parity >3), nonparous women had a higher OR (95% CI, 1.4-16.7). On the multiple logistic regression analysis including the sexual debut age, the marital status, parity, cytology, and the HPV groups, the A9 group had a significant OR for CIN (6.1; 95% CI, 1.6-23.6).

Conclusions:

The risk of CIN was higher for women infected with the HPV-A9 group after multiple logistic regression analysis. The other clinical risk factors were not significant factors of CIN.

Prevalence, viral load, and physical status of HPV 16 and 18 in cervical adenosquamous carcinoma

Adenosquamous carcinoma of the uterine cervix is a rare mixture of malignant squamous and glandular epithelial elements and accounts for approximately 10% of cervical carcinomas. The aims of the present study were to evaluate the prevalence, physical status, and viral load of HPV 16 and 18 in adenosquamous carcinoma. Formalin-fixed paraffin-embedded tissue samples from 20 cases of histologically diagnosed adenosquamous carcinoma were examined. The squamous and glandular components were separately microdissected and analyzed for their HPV DNA subtype, viral load, and physical status using real-time polymerase chain reaction (PCR). The percentages of HPV 16- and 18-positive cases among all the HPV-positive cases were 36.8% (7/19) and 57.9% (11/19) in the squamous epithelial elements and 33.3% (6/18) and 61.1% (11/18) in the glandular elements, respectively. PCR analysis with E2 primers revealed that seven of eleven (63.6%) HPV 18-positive cases had the pure integrated form in both elements. The mean HPV 16 DNA copy numbers/cell was 7.22 in the squamous elements and 1.33 in the glandular elements (p=0.04) while the corresponding mean HPV 18 DNA copy numbers/cell was 1.50 and 0.89, respectively. The prevalence of HPV 18 in adenosquamous carcinoma was high and many HPV 18-positive cases were the pure integrated form resulting in very low copy numbers/cell. It is possible that more aggressive transformation with early integration of HPV 18 results in cases with greater chromosomal instabilities, higher growth rates, and rapid progression.

Immunogenicity, reactogenicity, and safety of human papillomavirus 16/18 AS04-adjuvanted vaccine in Japanese women: interim analysis of a phase II, double-blind, randomized controlled trial at month 7

A phase II, double-blind, controlled randomized multicenter study with human papillomavirus (HPV) 16/18 AS04 (3-O-desacyl-4'-monophosphoryl lipid A and aluminum hydroxide)-adjuvanted vaccine is ongoing in Japanese women aged 20 to 25 years. An interim analysis was performed at month 7 (1 month after the third dose of vaccine) to determine reactogenicity, safety, and immunogenicity of the vaccine and to evaluate the baseline HPV-16/18 seropositivity and DNA status of women. In the HPV-16/18 group (according-to-protocol cohort for immunogenicity analysis), 100% seroconversion was observed against HPV-16 and HPV-18 at month 6 (5 months after the second dose) and at month 7. At month 7, anti-HPV-16 geometric mean titer (GMT) was 7441.0 enzyme-linked immunosorbent assay units/mL and anti-HPV-18 GMT was 3805.4 enzyme-linked immunosorbent assay units/mL, which is, respectively, 250- and 168-fold higher than GMTs observed after natural infection with HPV-16 or HPV-18. In the total vaccinated cohort, the seropositivity rates against HPV-16 and HPV-18 at study entry were 17.3% and 15.8%, respectively. At the same time point, HPV-16 and HPV-18 DNA was detected in 6.5% and 4.0% of the women, respectively. The immunogenicity of the HPV-16/18 vaccine and the HPV prevalence before vaccination in Japanese women are in line with what was observed in other populations. Injection site symptoms and some general symptoms were reported more frequently in the HPV-16/18 group than in the hepatitis A vaccine group but had no impact on compliance with completion of the vaccination course. Overall, the HPV-16/18 vaccine had a good safety profile, was well tolerated, and is highly immunogenic in the study population of Japanese women.

Differences in the risk of cervical cancer and human papillomavirus infection by education level

BACKGROUND

Cervical cancer risk is associated with low education even in an unscreened population, but it is not clear whether human papillomavirus (HPV) infection follows the same pattern.

METHODS

Two large multicentric studies (case-control studies of cervical cancer and HPV prevalence survey) including nearly 20 000 women. GP5+/GP6+ PCR was used to detect HPV.

RESULTS

Education level was consistently associated with cervical cancer risk (odds ratio (OR) for 0 and >5 years vs 1-5 years=1.50, 95% confidence interval (CI): 1.25-1.80 and 0.69, 95% CI: 0.57-0.82, respectively, P for trend <0.0001). In contrast, no association emerged between education level and HPV infection in either of the two IARC studies. A majority of the women studied had never had a Pap smear. The association between low education level and cervical cancer was most strongly attenuated by adjustment for age at first sexual intercourse and first pregnancy. Parity and screening history (but not lifetime number of sexual partners, husband's extramarital sexual relationships, and smoking) also seemed to be important confounding factors.

CONCLUSION

The excess of cervical cancer found in women with a low socio-economic status seems, therefore, not to be explained by a concomitant excess of HPV prevalence, but rather by early events in a woman's sexually active life that may modify the cancer-causing potential of HPV infection.

Human papillomavirus infections among Japanese women: age-related prevalence and type-specific risk for cervical cancer

To obtain baseline data for human papillomavirus (HPV) screening and vaccination in Japan, we analyzed HPV DNA data from 2282 Japanese women (1517 normal cytology, 318 cervical intraepithelial neoplasia [CIN] grade 1, 307 CIN2-3, and 140 invasive cervical cancer [ICC]) that visited the University of Tsukuba Hospital or Ibaraki Seinan Medical Center Hospital for screening or treatment of cervical diseases between 1999 and 2007. An L1-based PCR method was used for individual HPV genotyping. The most common HPV types in ICC were, in order of decreasing prevalence, HPV16 (40.5%), HPV18 (24.4%), HPV52 (8.4%), HPV58 (3.1%), and HPV33 (3.1%). Based on the comparison of HPV type distributions between normal cytology and CIN2-3 and ICC, estimated risk of disease progression varied considerably by genotype: HPV16, HPV18, HPV31, HPV33, HPV35, HPV52, and HPV58 (prevalence ratio, 1.92; 95% confidence interval 1.58-2.34); other oncogenic types (0.31, 95% confidence interval 0.19-0.50); and non-oncogenic types (0.09, 95% confidence interval 0.03-0.43). HPV16 and/or HPV18, including coinfections with other types, contributed to 67.1% of ICC and 36.2% of CIN2-3 among Japanese women. More importantly, the overall prevalence of HPV16 and/or HPV18 varied greatly according to the women's age: highest in women aged 20-29 years (ICC, 90.0%; CIN2-3, 53.9%), decreasing with age thereafter, and lowest in women aged 60 years or older (ICC, 56.3%; CIN2-3, 25.0%). In conclusion, type-specific HPV testing may help identify Japanese women at high risk of progression to CIN2-3 and cancer. In Japan, current HPV vaccines are estimated to provide approximately 70% protection against ICC and may be more useful in reducing the incidence of cervical cancer and precancer in young women of reproductive age.

[Protection against uterine cervical cancer by HPV vaccines]

Research literature has definitively shown HPV to be a necessary cause of cervical cancer. HPV is highly prevalent in sexually active populations and its natural history is now traceable thanks to recent advances in technology. HPV-like particle can now be synthesized and assembled in vitro to constitute the major virion protein L1, and this technology has been exploited to produce HPV-L1-VLP vaccines. Now, HPV-related diseases can thus be prevented by commercially available HPV prophylactic vaccines such as Gardasil (recombinant HPV genotype 6/11/16/18) and Cervarix (recombinant HPV genotype 16/18). These advances have dramatically changed the administration of cervical cancer screening programs.

Recommendations for cervical cancer prevention in Asia Pacific

Asia Oceania includes countries from both the Asia Pacific region and Australasia, which cover very diverse geographical areas and populations as well as bearing 52% of the cervical cancer burden in the world. Human papillomavirus (HPV) genotype distribution in women with normal cytology varies between countries in this region, as well as with the distribution typically observed in worldwide estimates or in Western countries. HPV-16 remains the predominant oncogenic type for high-grade cervical dysplasia and cervical cancer across the region, and HPV-18 is generally among the five most common types. HPV-58 is commonly found in cervical cancer as well as in women with normal cytology, and HPV-31, 33 and 35 are relatively less frequent in these regions compared to the West. While screening programmes have been proposed and implemented in several populations, successful programmes are rather limited and the majority of countries still have no or minimal screening services. Prophylactic HPV vaccination will only be feasible when it becomes affordable, thus the current priority and the short-term goal for cervical cancer control is to identify feasible and effective screening measures, and to find the most effective way to combine vaccination with sustainable screening programmes. This Regional Report has carefully described the disease burden of HPV and cervical cancer and the current situations in cervical cancer prevention for many countries in the Asia Oceania region. These data identify the many challenges and opportunities to be considered for policy decisions for cervical cancer control. Furthermore, this report presents the results of advanced decision analytic models calibrated to countries in the region that provide early insight into what strategies are most promising and those likely to be cost-effective and affordable. It thus provides a synthesis of the available evidence-based scientific information, in the context of a significant and systematic international review, that is likely to be useful to governments and public health providers.