High-risk Human Papillomavirus Testing in Young Japanese Women with Atypical Squamous Cells of Undetermined Significance

INTRODUCTION: The mortality due to uterine cervical cancer has been gradually increasing in women under 40 years of age (U40) in Japan. We investigated the effect of high-risk human papillomavirus (HR-HPV) on U40 subjects without any overt cytological abnormalities. MATERIALS AND METHODS: We retrospectively examined the clinical data, including the findings of a cobas 4800 HPV test that was approved in Japan in 2013 to triage women with atypical squamous cells of undetermined significance (ASC-US) and a histological examination in 589 Japanese women. RESULTS: The overall prevalence rate of HR-HPV was 34.5%. Biopsy-confirmed cervical intraepithelial neoplasia (CIN) 2, or worse (CIN2+) was identified in 45.1% (23/51) of HR-HPV-positive women with ASC-US, who underwent colposcopy immediately. The mean period from the HPV test to the diagnosis of CIN2+ was 3.7 months. CIN2+ was more common (69.6%) in U40 patients. The rates of single or multiple infections of HPV-16, HPV-18, and 12 other HR-HPV (31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68) in CIN2+ U40 patients were 31.3%, 0%, and 81.3%, respectively. The relative risk for CIN 2+ among U40 women with HPV-16 was not significantly different from that of the patients with infection of any of the 12 other HR-HPVs. CONCLUSION: The results of this study suggest that the 12 other HR-HPVs have a potential to generate high-grade cervical lesions among young women, and the examination rate of colposcopy should be increased.