Pre-vaccination epidemiology of human papillomavirus infections in Japanese women with abnormal cytology.

AIM To investigate the pre-vaccination epidemiology of genital human papillomavirus (HPV) infections and genotypes in women with abnormal cytology in Nagasaki, Japan. MATERIAL AND METHODS We performed Pap smear tests, biopsies and HPV genotype testing in Nagasaki Prefecture from August 2007 through November 2009. RESULTS During the study period, serial samples of uterine cervical specimens were obtained from 539 subjects with abnormal cytology and/or squamous intraepithelial lesions (SIL) confirmed previously, or with clinically suspected invasive cervical cancer. In 119 HPV-positive subjects with low-grade SIL, the three most prevalent high-risk HPV genotypes were HPV52 (21.8%; 26/119), HPV16 (20.2%; 24/119) and HPV56 (17.6%; 21/119). In 199 women, 127 HPV-positive subjects with high-grade SIL and 67 HPV-positive subjects with squamous cell carcinoma (SCC), the three most prevalent high-risk HPV genotypes were HPV16 (44.3%; 86/194), HPV52 (20.6%; 40/194) and HPV58 (16.0%; 31/194). CONCLUSION Compared with the distribution of high-risk HPV genotypes in other countries, HPV52 was a more common genotype in Nagasaki. With disease progression to SCC, the distribution of high-risk HPV56 belonging to the A6 HPV family decreased, while HPV16 and HPV52 belonging to the A9 HPV family persisted. Our data provide an important resource to address the case for vaccination against HPV genotypes other than HPV16 and HPV18 in Japan.