Human Papillomavirus Genotypes in Cervical Intraepithelial Neoplasia Grade 3

Abstract

There are few large case series describing the human papillomavirus (HPV) genotypes found in women diagnosed with rigorously reviewed cervical intraepithelial neoplasia grade 3 (CIN3), cervical precancer. The Atypical Squamous Cells of Undetermined Significance (ASCUS) and Low-Grade Squamous Intraepithelial Lesion (LSIL) Triage Study (ALTS) was a clinical trial to evaluate the best management strategies for women with equivocal (ASCUS) or mildly abnormal (LSIL) Pap tests. During enrollment and the 2-year follow-up, 608 women had a histopathologic diagnosis of CIN3 and PCR-based HPV genotyping results on cervical specimens. The genotyping results were ranked hierarchically according to cancer risk: HPV16 > other carcinogenic HPV > noncarcinogenic HPV > PCR negative. Among the 608 women diagnosed with CIN3, 601 (98.8%) cases were positive for any HPV genotype and 95.4% for any carcinogenic HPV. HPV16 (59.9%), HPV31 (18.1%), HPV52 (14.8%), HPV51 (14.0%), and HPV18 (13.2%) were the five most common HPV genotypes detected. Younger age, consensus histologic confirmation, smoking, and multiparity increased the likelihood of testing HPV 16 positive. Specifically, HPV16-positive CIN3 occurred at a younger age than CIN3 positive for other carcinogenic HPV genotypes (median of 23.5 years versus 25 years, respectively; P = 0.0003, Kruskal-Wallis). HPV16-positive CIN3 was more commonly diagnosed in younger women (versus older women), with consensus diagnosis (versus some disagreement between reviewers), and in smokers (versus nonsmokers), and was less commonly diagnosed in multiparous women compared CIN3 positive for other carcinogenic HPV genotypes. In populations vaccinated against HPV16 (and HPV18), the median age of CIN3 in women with ASCUS and LSIL cytology should shift to older ages, possibly permitting later age at first screening.