Genotype prevalence and age distribution of human papillomavirus from infection to cervical cancer in Japanese women: A systematic review and meta-analysis

BACKGROUND

National HPV vaccination coverage in Japan is less than one percent of the eligible population and cervical cancer incidence and mortality are increasing. This systematic review and meta-analysis aimed to provide a comprehensive estimate of HPV genotype prevalence for Japan.

METHODS

English and Japanese databases were searched to March 2021 for research reporting HPV genotypes in cytology and histology samples from Japanese women. Summary estimates were calculated by disease stage from cytology only assessment - Normal, ASCUS, LSIL, HSIL and from histological assessment - CIN1, CIN2, CIN3/AIS, ICC (ICC-SCC, and ICC-ADC), and other. A random-effects meta-analysis was used to calculate summary prevalence estimates of any-HPV, high-risk (HR) and low-risk (LR) vaccine types, and vaccine genotypes (bivalent, quadrivalent, or nonavalent). This study was registered with PROSPERO: CRD42018117596.

RESULTS

A total of 57759 women with normal cytology, 1766 ASCUS, 3764 LSIL, 2017 HSIL, 3130 CIN1, 1219 CIN2, 869 CIN3/AIS, and 4306 ICC (which included 1032 ICC-SCC, and 638 ICC-ADC) were tested for HPV. The summary estimate of any-HPV genotype in women with normal cytology was 15·6% (95% CI: 12·3-19·4) and in invasive cervical cancer (ICC) was 85·6% (80·7-89·8). The prevalence of HR-HPV was 86·0% (95% CI: 73·9-94·9) for cytological cases of HSIL, 76·9% (52·1-94·7) for histological cases of CIN3/AIS, and 75·7% (68·0-82·6) for ICC. In women with ICC, the summary prevalence of bivalent vaccine genotypes was 58·5% (95% CI: 52·1-64·9), for quadrivalent genotypes was 58·6% (52·2-64·9) and for nonavalent genotypes was 71·5% (64·9-77·6), and of ICC cases that were HPV positive over 90% of infections are nonavalent vaccine preventable. There was considerable heterogeneity in all HPV summary estimates and for ICC, this heterogeneity was not explained by variability in study design, sample type, HPV assay type, or HPV DNA detection method, although studies published in the 1990s had lower prevalence estimates of any-HPV and HR HPV genotypes.

INTERPRETATIONS

HPV prevalence is high among Japanese women. The nonavalent vaccine is likely to have the greatest impact on reducing cervical cancer incidence and mortality in Japan.

Low-grade squamous intraepithelial lesion on Papanicolaou test: follow-up rates and stratification of risk for high-grade squamous intraepithelial lesion

INTRODUCTION

Low-grade squamous intraepithelial lesion (LSIL) Papanicolaou test is associated with moderate risk of high-grade squamous intraepithelial lesion (HSIL) at colposcopic biopsy. High-risk human papillomavirus (hrHPV) cotesting risk stratifies patients with LSIL Papanicolaou test, with higher rates of HSIL for those hrHPV+. hrHPV genotyping is not considered in current LSIL management algorithms.

MATERIALS AND METHODS

We performed a 2-year retrospective review of LSIL Papanicolaou tests in patients 25 to 65 years old to assess rates of follow-up and HSIL at biopsy. Patient age, hrHPV cotest and genotype results, prior screening results, and follow-up testing for 3 years were recorded.

RESULTS

A total of 71.5% (376 of 526) of patients had at least 1 follow-up colposcopic biopsy; 18% had HSIL on follow-up, including 20% of hrHPV+ and 12% of hrHPV-. HSIL at biopsy was most common when HPV16/18 was present (32%) and when multiple subtypes were detected (46%) versus when non-16, non-18 hrHPV alone was present (16%) or hrHPV was negative (12%). Of those hrHPV-, 5 of 22 (23%) with a prior screening abnormality had HSIL versus 1 of 27 (4%) for those without prior abnormalities. Follow-up occurred more commonly for hrHPV+ cotests (82%) than hrHPV- cotests (54%). No differences in follow-up rate based on hrHPV genotyping was seen.

CONCLUSIONS

The highest HSIL rates were seen when HPV16/18 was present (32%). HSIL rates were similar for those hrHPV- (12%) and non-16, non-18 hrHPV+ (16%). Follow-up was more common for those hrHPV+, but genotype results did not impact follow-up rates. Past screening results may impact risk of HSIL for hrHPV- cases.

Comparison of human papillomavirus genotyping and cytology triage, COMPACT Study: Design, methods and baseline results in 14 642 women

Although cytology‐based screening programs have significantly reduced mortality and morbidity from cervical cancer, the global consensus is that primary human papillomavirus (HPV) testing for cervical screening increases detection of high‐grade cervical intraepithelial neoplasia (CIN) and invasive cancer. However, the optimal triage strategy for HPV‐positive women to avoid over‐referral to colposcopy may be setting specific. As Japan requires data that have been generated domestically to modify screening guidelines, we conducted a 3‐year prospective study, COMparison of HPV genotyping And Cytology Triage (COMPACT), to evaluate the potential role of HPV16/18 partial genotyping and cytology for primary HPV screening. In total, 14 642 women aged 20 to 69 years undergoing routine screening at 3 centers in Hokkaido were enrolled. Conventional cytology and HPV testing were carried out. Women with abnormal cytology or HPV16/18 positivity underwent colposcopy. Those with 12 other high‐risk (hr) HPV types underwent repeat cytology after 6 months. Primary study endpoints were detection of high‐grade cervical disease defined as CIN2/CIN3 or greater as determined by consensus pathology. Prevalence of cytological abnormalities was 2.4%. hrHPV, HPV 16, and HPV 18 were detected in 4.6%, 0.9%, and 0.3% of women, respectively. HPV16/18 were detected in all (8/8) invasive cervical cancers and in all (2/2) adenocarcinomas in situ. Both cytological abnormalities and hrHPV positivity declined with increasing age. This is the first Japanese study to investigate the role of partial genotyping and cytology in an HPV‐based screening program. Results should help policy‐makers develop guidelines for future cervical screening programs and management of cervical abnormalities based on HPV genotype.