Human papillomavirus genotypes and the cumulative 2-year risk of cervical precancer

Background. Prospective data on the risks of cervical precancer associated with specific human papillomavirus (HPV) genotypes are limited. Methods. In 5060 women participating in the Atypical Squamous Cells of Undetermined Significance/Low-Grade Squamous Intraepithelial Lesions Triage Study (ALTS), we determined the cumulative 2-year risks of cervical intraepithelial neoplasia (CIN) grade 2 or more severe (>= CIN2) and of grade 3 or more severe (>= CIN3) for 38 individual HPV genotypes, as detected by polymerase chain reaction. Results. The most common HPV genotypes detected at baseline, in descending order of prevalence, were 16, 52, 51, 31, 18, 53, 39, 56, 62, 59, and 58. When detected as a single-type HPV infection, HPV-16 had a 2-year cumulative risk of 50.6% (95% confidence interval [CI], 44.1%-57.2%) for >= CIN2 and 39.1% (95% CI, 32.9%-45.7%) for >= CIN3. For other singly detected carcinogenic HPV types, the risk of >= CIN2 ranged from 4.7% (for HPV-59) to 29.5% (for HPV-31), and the risk of >= CIN3 ranged from 0.0% (for HPV-59) to 14.8% (for HPV-31). Multiple infections with HPV genotypes of different risk classes resulted in a risk that was similar to, and not significantly different from, the risk observed for the HPV genotype of the highest risk class. Conclusions. Genotype-specific HPV testing may be useful for identifying women with atypical squamous cells of undetermined significance and low-grade squamous intraepithelial lesions who are at higher and lower risk of prevalent and incipient cervical precancer.