Understanding the Epidemiology of HPV and Intraepithelial Lesions in Men

Considered the most common sexually transmitted infection (STI) in the United States, HPV impacts over 24 million Americans. Each year, it’s estimated that 5.5 million new HPV cases are identified and this cancer-causing STI is one that deeply challenges public health.

A new study in The Lancet sought to address the epidemiology of anal HPV and HSIL among nearly 30,000 men as a way to help guide anal cancer prevention strategies. Within this study, they worked to evaluate age-specific prevalence of anal HPV and/or HSIL within men by stratifying by HIV status, age, and sexuality.

A pooled analysis across dozens of studies, the researchers utilized individual-level data to better understand how they could provide better intervention and prevention efforts against anal cancer.

Sixty-four studies were ultimately utilized to assess data in regards to 29,900 men. The authors noted that, “Among HIV-negative MSW anal HPV16 prevalence was 1·8% (91 of 5190) and HR-HPV prevalence was 6·9% (345 of 5003); among HIV-positive MSW the prevalences were 8·7% (59 of 682) and 26·9% (179 of 666); among HIV-negative MSM they were 13·7% (1455 of 10 617) and 41·2% (3798 of 9215), and among HIV-positive MSM 28·5% (3819 of 13 411) and 74·3% (8765 of 11 803). In HIV-positive MSM, HPV16 prevalence was 5·6% (two of 36) among those age 15–18 years and 28·8% (141 of 490) among those age 23–24 years (ptrend=0·0091); prevalence was 31·7% (1057 of 3337) among those age 25–34 years and 22·8% (451 of 1979) among those age 55 and older (ptrend<0·0001). HPV16 prevalence in HIV-negative MSM was 6·7% (15 of 223) among those age 15–18 and 13·9% (166 of 1192) among those age 23–24 years (ptrend=0·0076); the prevalence plateaued thereafter (ptrend=0·72).”

Moreover, the research team reported that there were similar age-specific patterns for those with anal high-risk HPV while there was no significant difference between anal high-risk HPV or HPV16 and age regardless of HIV status in men who have sex with women. The authors noted “consistent with previous research, patterns of anal HR-HPV prevalence, most notably for HPV16, showed HIV status and sexuality to be important population-level determinants of anal HPV infection in men. Anal HPV data were particularly abundant for both HIV-negative and HIV-positive MSM, allowing robust estimates of age-specific changes in HPV infection, which notably indicated a rapid increase in prevalence from the age of 15 years to 24 years.” The authors also reported that for HIV-negative men who have sex with women, high-risk HPV prevalence was quite low when compared to other risk groups and ages.

Ultimately, this study wholly underscores the importance of providing and promoting HPV vaccines regardless of gender and before sexual activity. Moreover, there is an increased need to fund and support research on anal cancer screening research for HIV-positive men who have sex with men. The HPV vaccine is a pivotal public health tool and as this study underscores, more work needs to be done to provide the vaccine larger scales to ensure equity and access.