Prevalence and Risk Factors of Human Papillomavirus Infection among Japanese Female People: A Nationwide Epidemiological Survey by Self-Sampling

Mapping recommendations towards an Asian Code Against Cancer (ACAC) as part of the World Code Against Cancer Framework: an Asian National Cancer Centers Alliance (ANCCA) initiative

This paper outlines the process undertaken by Asian National Cancer Centers Alliance (ANCCA) members in working towards an Asian Code Against Cancer (ACAC). The process involves: (i) identification of the criteria for selecting the existing set of national recommendations for ACAC (ii) compilation of existing national codes or recommendations on cancer prevention (iii) reviewing the scientific evidence on cancer risk factors in Asia and (iv) establishment of one or more ACAC under the World Code Against Cancer Framework. A matrix of national codes or key recommendations against cancer in ANCCA member countries is presented. These include taking actions to prevent or control tobacco consumption, obesity, unhealthy diet, physical inactivity, alcohol consumption, exposure to occupational and environmental toxins; and to promote breastfeeding, vaccination against infectious agents and cancer screening. ANCCA will continue to serve as a supportive platform for collaboration, development, and advocacy of an ACAC jointly with the International Agency for Research on Cancer/World Health Organization (IARC/WHO).

Community Screening for High-Risk Human Papilloma Virus Infection using Self-Sampling and 'Point-Of-Care' Test

OBJECTIVE

HR-HPV types 16 and 18 are responsible for pre-invasive and invasive lesions of the cervix, accounting for 70-80% of the total subtypes. The aim of this study was to investigate the prevalence of high-risk HPV subtypes 16 and 18 in self-collected vaginal samples using real-time micro-PCR and to study the acceptability of self-sampling.

METHODS

Eligible women (30-65 years) were screened from a semi-urban area of Uttarakhand (India) using self-sampling. High-risk HPV genotypes (16/31 and 18/45) were tested using real-time micro-PCR technique with results available in one hour. The positive results were validated by standard RT-PCR for high-risk HPV 16, 18, separately and for 12 other high-risk genotypes, combined. Ease of the procedure, level of comfort, and recommendation to other women were studied and the acceptability of self-sampling was analyzed using the Likert scale.

RESULT

Of 975 eligible women screened, 45 participants tested positive for HR-HPV (16/31,18/45) using real-time micro-PCR with a prevalence of 4.6%. Positive samples were further tested through routine RT-PCR and 60% were found to be HR-HPV 16 and 18 positive. For self-sampling, 96.72% (n=943) participants were 'very satisfied' and 94.15% (n=918) found self-sampling to be 'very comfortable' and 88.51% (n=863) stated that they will strongly recommend this test to other eligible women in the community.

CONCLUSION

We conclude that HR-HPV testing with limited genotyping showed a prevalence of 4.6%, 60% of these were HPV 16/18 positive. Point of care testing was feasible in the community and self-sampling was acceptable.

Prevalence of Human Papillomavirus Types 16/18 and Effect of Vaccination among Japanese Female General Citizens in the Vaccine Crisis Era

The Japanese government withdrew its recommendation for human papillomavirus (HPV) vaccination in June 2013 and resumed it in April 2022. This period is known as the vaccine crisis in Japan. This study aimed to elucidate the prevalence and genotype distribution of HPV among Japanese female citizens, and the effect of vaccination against HPV-16/18 in the era of the vaccine crisis. We recruited Japanese female citizens and asked them to provide self-collected samples from the vaginal wall using cotton swabs for HPV genotyping. Furthermore, we collected the participants' characteristics, including lifestyle and experience of vaccination against HPV, to determine the significant association with HPV infection. HPV-16/18 positivity was found in 5.6% (115/2044) of participants. The highest vaccination rate was observed in the age group of 20-24 years (60.6%), whereas the lowest HPV-16/18 positivity was observed in the age group of 45-49 years (2.8%), followed by the age group of 20-24 years (4.0%). Experience with HPV vaccination significantly reduced the risk of HPV-16/18 infection (adjusted odds ratio, 0.047; 95% confidence interval, 0.011-0.196). Vaccinated women were much less likely to be infected by HPV-16/18, regardless of the HPV vaccine type or the vaccination dose.

Health impact and cost effectiveness of implementing gender-neutral HPV vaccination in Japan

OBJECTIVE

To assess the public health impact and cost effectiveness of gender-neutral vaccination (GNV) versus female-only vaccination (FOV) with human papillomavirus (HPV) vaccination in Japan.

METHODS

We modeled the public health impact and cost effectiveness of GNV versus FOV to prevent HPV-associated diseases in Japan over the next 100 years. We used one-way sensitivity analyses to examine the impact of varying key model input parameters and conducted scenario analyses to explore the effects of varying the vaccination coverage rate (VCR) of each cohort.

RESULTS

In the base-case analysis, GNV averted additional cancer cases (17,228 female/6,033 male) and deaths (1,892 female/1,849 male) compared to FOV. When all HPV-associated diseases were considered, GNV had an incremental cost-effectiveness ratio of ¥4,732,320 (US$35,987)/quality-adjusted life year gained compared to FOV. The model was most sensitive to the discount rate and the disutility associated with HPV-related diseases. GNV had greater relative public health benefits when the female VCR was lower and was cost effective at a female VCR of 30%.

CONCLUSIONS

Immediate implementation of GNV would reduce the disease burden and mortality associated with HPV in Japan, and would be cost effective compared to FOV if the female VCR remains low (30%).

Status and epidemiological characteristics of high-risk human papillomavirus infection in multiple centers in Shenyang

The different human papillomavirus (HPV) strains cause warts in various regions of the body. However, considering that the status and genotype distribution of HPV infection in women in Shenyang remain unknown, herein, we investigated the epidemiological characteristics of high-risk HPV (HR-HPV) infection in women in Shenyang, as well as the current state of HPV infection in Shenyang, to provide a theoretical basis for the prevention and treatment of cervical cancer. From December 2018 to December 2021, 6,432 urban and rural women from the Liaoning Cancer Hospital and the Sujiatun Women and Infants’ Hospital were assessed via the Thinprep cytology test (TCT) and HR-HPV detection. Of the 5,961 women enrolled, 739 were HPV positive (12.40%) and 562 were TCT positive (9.43%). Statistical analyses identified the following HPV risk factors: high school education or lower [OR = 1.426 (1.199–1.696), p < 0.001], age at first sexual encounter ≤ 19 years [OR = 1.496 (1.008–2.220), p = 0.046], and number of sexual partners > 1 [OR = 1.382 (1.081–1.768), p = 0.010], atypical squamous cells of undetermined significance (ASCUS) and above [OR = 10.788 (8.912–13.060), p < 0.001], non-condom-based contraception [OR = 1.437 (1.103–1.871), p = 0.007], nationalities other than Han [OR = 1.690 (1.187–2.406), p = 0.004], rural residence [OR = 1.210 (1.031–1.419), p = 0.020]. Compared to the HPV infection rate of women aged 56–65, that in women aged 35–45 [OR = 0.687 (0.549–0.860), p = 0.001] and 46–55 [OR = 0.740 (0.622–0.879), p = 0.001] decreased significantly. To conclude, risk factors of HPV infection among female patients include high school age and below, initial sexual encounter at age ≤ 19 years, number of sexual partners > 1, ASCUS and above, non-condom contraception, nationalities other than Han nationality and rural population. Collectively, this study provides insights for the improved prevention and treatment of cervical cancer.

Risk Factors Associated With Human Papillomavirus Infection, Cervical Cancer, and Precancerous Lesions in Large-Scale Population Screening

Cervical cancer is the most common gynecological malignancy and screening for risk factors with early detection has been shown to reduce the mortality. In this study, we aimed to analyze the characteristics and risk factors of human papillomavirus (HPV) infection and precancerous lesions in women and provide clinical evidence for developing strategies to prevent cervical precancerous lesions and cancer in women. Furthermore, we evaluated the influencing factors for high-risk HPV infection. From April 2018 to December 2021, 10,628 women were recruited for cervical cancer screening at Liaoning Cancer Hospital, Shenyang Sujiatun District Women’s and Infants Hospital, Benxi Manchu Autonomous County People’s Hospital, and Shandong Affiliated Hospital of Qingdao University. The study participants were tested to determine if they were HPV-positive (HPV +) or underwent thinprep cytology test (TCT) for atypical squamous cells of undetermined significance (ASCUS) and above. Furthermore, colposcopies and biopsies were performed for the histopathological examination. Finally, 9991 cases were included in the statistical analysis, and the factors influencing HPV infection and those related to cervical cancer and precancerous lesions were analyzed. HPV + infection, high-grade squamous intraepithelial lesion-positive (CINII +) in cervical high-grade intraepithelial neoplasia, and early cervical cancer diagnosis rates were 12.45, 1.09, and 95.41%, respectively. The potential risk factors for HPV were education ≤ high school [odds ratio (OR) = 1.279 (1.129–1.449), P < 0.001], age at initial sexual activity ≤ 19 years [OR = 1.517 (1.080–2.129), P = 0.016], sexual partners > 1 [OR = 1.310 (1.044–1.644), P = 0.020], ASCUS and above [OR = 11.891 (10.105–13.993), P < 0.001], non-condom contraception [OR = 1.255 (1.059–1.487), P = 0.009], and HSIL and above [OR = 1.541 (1.430–1.662), P < 0.001]. Compared with women aged 56–65 and 35–45 years [OR = 0.810 (0.690–0.950), P = 0.010] the HPV infection rate was significantly lower in those aged 46–55 years [OR = 0.79 (0.683–0.915), P = 0.002]. Furthermore, ≤ high school age [OR = 1.577 (1.042–2.387), P = 0.031], not breastfeeding [OR = 1.763 (1.109–2.804), P = 0.017], ASCUS and above [OR = 42.396 (28.042–64.098), P < 0.001] were potential risk factors for cervical cancer and precancerous lesions. In women with HPV infection, ≤ high school education level, initial sexual activity at ≤ 19 years of age, number of sexual partners > 1, ASCUS and above, non-condom contraception, HSIL and above were risk factors for HPV infection. Compared with women aged 56–65 years, those aged 35–45 and 46–55 years had significantly lower HPV infection rates, and high school age and below, non-breastfeeding, and ASCUS and above were all potential risk factors for cervical cancer and precancerous lesions.