Objective: Immunosuppression may increase risk for some skin cancers. We evaluated skin cancer epidemiology among persons with AIDS.
Design: We linked data from population-based US AIDS and cancer registries to evaluate risk of nonkeratinocytic skin cancers (melanoma, Merkel cell carcinoma, and appendageal carcinomas, including sebaceous carcinoma) in 497 142 persons with AIDS.
Methods: Standardized incidence ratios (SIRs) were calculated to relate skin cancer risk to that in the general population. We used logistic regression to compare risk according to demographic factors, CD4 cell count, and a geographic index of ultraviolet radiation exposure.
Results: From 60 months before to 60 months after AIDS onset, persons with AIDS had elevated risks of melanoma (SIR = 1.3, 95% confidence interval 1.1–1.4, n = 292 cases) and, more strongly, of Merkel cell carcinoma (SIR = 11, 95% confidence interval 6.3–17, n = 17) and sebaceous carcinoma (SIR = 8.1, 95% confidence interval 3.2–17, n = 7). Risk for appendageal carcinomas increased with progressive time relative to AIDS onset (P trend = 0.03). Risk of these skin cancers was higher in non-Hispanic whites than other racial/ethnic groups, and melanoma risk was highest among men who have sex with men. Melanoma risk was unrelated to CD4 cell count at AIDS onset (P = 0.32). Risks for melanoma and appendageal carcinomas rose with increasing ultraviolet radiation exposure (P trend <10−4 and P trend = 10−3, respectively).
Conclusion: Among persons with AIDS, there is a modest excess risk of melanoma, which is not strongly related to immunosuppression and may relate to ultraviolet radiation exposure. In contrast, the greatly increased risks for Merkel cell and sebaceous carcinoma suggest an etiologic role for immunosuppression.
aDivision of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville Maryland, USA
bINSERM, U720, France
cUPMC Univ Paris 06, UMR S720, Paris, France
dMedical Service, Department of Veterans Affairs Medical Center, Oklahoma City, Oklahoma, USA
eFred Hutchinson Cancer Research Center, Seattle, Washington, USA.
Received 25 June, 2008
Revised 27 October, 2008
Accepted 4 November, 2008
Correspondence to Eric A. Engels, Division of Cancer Epidemiology and Genetics, National Cancer Institute, 6120 Executive Blvd., Room 7076, Rockville, MD 20892, USA. E-mail: firstname.lastname@example.org