Anal cancer incidence in men with HIV who have sex with men: are black men at higher risk?

Abstract

Objective: To assess differences in anal cancer incidence between racial/ethnic groups among a clinical cohort of men with HIV who have sex with men.

Design: Clinical cohort study.

Methods: We studied men who have sex with men (MSM) in the Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) who initiated antiretroviral therapy (ART) under HIV care in CNICS. We compared anal cancer incidence between Black and non-Black men and calculated hazard ratios controlling for demographic characteristics (age, CNICS site, year of ART initiation), HIV disease indicators (nadir CD4+, peak HIV RNA), and co-infection/behavioral factors including hepatitis B virus (HBV), hepatitis C virus (HCV), tobacco smoking and alcohol abuse.

Results: We studied 7473 MSM with HIV who contributed 41 810 person-years of follow-up after initiating ART between 1996 and 2014 in CNICS. Forty-one individuals had an incident diagnosis of anal cancer under observation. Crude rates of anal cancer were 204 versus 61 per 100 000 person-years among Black versus non-Black MSM. The weighted hazard ratio for anal cancer in Black MSM (adjusting for demographics, HIV disease factors, and co-infection/behavioral factors) was 2.37 (95% confidence interval: 1.17, 4.82) compared to non-Black MSM.

Conclusions: In this large multicenter cohort, Black MSM were at significantly increased risk for anal cancer compared to non-Black MSM. Further detailed studies evaluating factors impacting anal cancer incidence and outcomes in Black men with HIV are necessary. Inclusion of more diverse study cohorts may elucidate modifiable factors associated with increased anal cancer risk experienced by Black MSM.

Fig. 1.. Crude and weighted risk curves for anal cancer diagnosis, stratified by race.

Solid line, non-Black; dashed line, Black. (a) Crude; (b) weights included age, nadir CD4⁺ cell count, peak HIV RNA, year of ART initiation, study site. (c) Weights included age, nadir CD4⁺ cell count, peak HIV RNA, year of ART initiation, smoking, alcohol use, injection drug use, hepatitis B, hepatitis C, study site. ART, antiretroviral therapy.

Fig. 1.. Crude and weighted risk curves for anal cancer diagnosis, stratified by race.

Solid line, non-Black; dashed line, Black. (a) Crude; (b) weights included age, nadir CD4⁺ cell count, peak HIV RNA, year of ART initiation, study site. (c) Weights included age, nadir CD4⁺ cell count, peak HIV RNA, year of ART initiation, smoking, alcohol use, injection drug use, hepatitis B, hepatitis C, study site. ART, antiretroviral therapy.