Men with HIV who have sex with men have elevated incidence of anal cancer

Patients with HIV demonstrated a significantly elevated incidence of anal cancer, with a particularly high risk among patients with AIDS, men who have sex with men and older patients, according to findings published in Journal of Clinical Oncology.

“People with advanced HIV disease (i.e., AIDS) have an elevated risk for in situ and invasive HPV-associated cancers, including anal cancer,” Vivian Colón-López, PhD, MPH, assistant professor at University of Puerto Rico, and colleagues wrote. “This elevated risk is consistent with a high incidence and persistence of anal HPV infection among individuals with HIV infection. Anal cancer risk associated with HIV infection is particularly high among men who have sex with men (MSM), with an estimated 37-fold increased risk compared with the general population.

The researchers evaluated trends in anal cancer incidence using linked data from cancer and HIV registries in nine regions of the United States for the period between 1996 and 2012. Colón-López and colleagues used standardized incidence ratios to compare anal cancer incidence between patients with HIV and the general population. They used Poisson regression to assess the incidence of anal cancer in different subgroups of patients with HIV.

A total of 447,953 patients had HIV. These patients had a much greater incidence of anal cancer than the general population (standardized incidence ratio, 19.1; 95% CI, 18.1-20). MSM demonstrated the highest incidence of anal cancer (standardized incidence ratio range, 33.2-38.7). Incidence also increased with age, and appeared higher among patients with AIDS compared with those without (i.e., HIV only; IRR = 3.82; 95% CI, 3.27-4.46).

Among patients with HIV, anal cancer incidence rose sharply from 1996 to 2000 (annual percentage change, 32.8%; 95% CI, –1 to 78.2). Incidence then plateaued from 2001 to 2008, eventually declining from 2008 to 2012 (annual percentage change, –7.2%; 95% CI, –14.4 to 0.6).

MSM with HIV only had high cumulative incidence after a 5-year period among those aged 45 to 59 years or older than 60 years (0.32%-0.33%). MSM with AIDS also demonstrated high rates among those aged 30 to 44 years, 45 to 59 years or older than 60 years (0.29%-0.65%).

“The results identify some subgroups with the highest cumulative incidence that may most benefit from screening and prevention,” the researchers wrote. “The recent apparent decline in incidence is encouraging and may reflect delayed benefits of increasing use of highly active ART. However, because anal cancer incidence increases with age, the overall burden of patients with this disease may start to increase again with the aging of the U.S. HIV population.”

Colón-López and colleagues noted that it would be necessary to continue monitoring anal cancer trends. – by Andy Polhamus

Disclosures: Colón-López reports no relevant financial disclosures.