The natural history of high-risk human papillomavirus (HR-HPV) at anus is not fully illustrated, especially by HIV status.
We performed a systematic literature review and meta-analysis of HPV prevalence across the full spectrum of anal diagnosis. Data on 6,792 normal cytology, 3,918 low-grade lesions, 1,151 high-grade lesions and 2,098 invasive anal cancers were extracted from 77 studies with stratification of HIV status and gender as far as possible.
Overall HPV prevalence increased with severity of anal lesion in men and women irrespective of HIV status. Among HPV-positive samples, HPV16 positivity increased with severity of anal lesion grade from 23-83% in HIV-negative and from 26-60% in HIV-positive men; from 13-87% in HIV-negative and from 17-75% in HIV-positive women. HPV16 less expressed in HIV-negative cancer compare to HIV-positive cases in men with prevalence ratio (PR) = 0.72 (95% CI: 0.63-0.82). Other HR-HPV types accounted for more important proportions of low- and high-grade lesions, but their contribution dropped in cancer. Only HPV16 accounted a greater proportion of HPV infection in cancer compared to normal cytology in HIV-negative (cancer:normal ratio = 5.00, 95% confidence interval [CI]: 4.41-5.67) and HIV-positive (cancer:normal ratio = 2.52, 95% CI: 2.21-2.88) individuals. Other non-HPV16 HR-HPV types were more prevalent in HIV-positive samples than HIV-negative counterparts across anal lesions in men and women.
HPV16 is uniquely carcinogenic at the anus, even in HIV-positive persons, and is the priority for cancer prevention.