Incidence and epidemiology of anal cancer in the multicenter AIDS cohort study.
OBJECTIVE
To examine the incidence and risk factors for anal cancer in a multicenter cohort of human immunodeficiency virus (HIV) positive and HIV-negative men who have sex with men followed between 1984 and 2006 (Multicenter AIDS Cohort Study).


METHODS
Prospective analysis using Poisson regression and Cox proportional hazard models and a nested case-control study using conditional logistic regression.


RESULTS
There were 28 cases of anal cancer among the 6,972 men who were evaluated. The incidence rate was significantly higher in HIV-positive men than in HIV-negative men (incidence rate = 69 vs 14 per 100,000 person-years). Among HIV-positive men, anal cancer incidence was higher in the highly active antiretroviral therapy (HAART) era than the pre-HAART era (incidence rate = 137 vs 30 per 100,000 person-years). In multivariate analysis restricted to the HAART era, anal cancer risk increased significantly with HIV infection (relative hazard = 4.7, 95% confidence interval = 1.3 to 17) and increasing number of unprotected receptive anal sex partners at the first 3 study visits (P trend = 0.03). Among HIV-positive men, current HAART use did not decrease anal cancer risk.


CONCLUSIONS
HIV-positive men had increased risk of anal cancer. Improved survival of HIV-positive individuals after HAART initiation may allow for sufficient time for human papillomavirus-associated anal dysplasias to develop into malignancies, thus explaining the increased incidence of anal cancer in the HAART era.
D'Souza
Gypsyamber
G
Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA. gdsouza@jhsph.edu
Wiley
Dorothy J
DJ
Li
Xiuhong
X
Chmiel
Joan S
JS
Margolick
Joseph B
JB
Cranston
Ross D
RD
Jacobson
Lisa P
LP
D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D001005:Anus Neoplasms / Q000150:complications / Q000453:epidemiology*; D002294:Carcinoma, Squamous Cell / Q000150:complications / Q000453:epidemiology*; D015331:Cohort Studies; D018450:Disease Progression; D006678:HIV; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy; D018451:Homosexuality, Male; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012307:Risk Factors; D047568:Unsafe Sex
D019380:Anti-HIV Agents