Objective: To evaluate the risk of cancers with and without a known infectious cause in HIV-infected persons.
Design: Retrospective cohort study.
Methods: Adult HIV-infected and matched HIV-uninfected members of Kaiser Permanente followed between 1996 and 2007 for incident AIDS-defining cancers (ADCs), infection-related non-AIDS-defining cancers (NADCs; anal squamous cell, vagina/vulva, Hodgkin's lymphoma, penis, liver, human papillomavirus-related oral cavity/pharynx, stomach) and infection-unrelated NADC (all other NADCs).
Results: We identified 20 277 HIV-infected and 202 313 HIV-uninfected persons. HIV-infected persons experienced 552 ADC, 221 infection-related NADC, and 388 infection-unrelated NADC. HIV-uninfected persons experienced 179 ADC, 284 infection-related NADC, and 3418 infection-unrelated NADC. The rate ratio comparing HIV-infected and HIV-uninfected persons for ADC was 37.7 [95% confidence interval (CI): 31.7–44.8], with decreases in the rate ratio over time (P < 0.001). The rate ratio for infection-related NADC was 9.2 (95% CI: 7.7–11.1), also with decreases in the rate ratio over time (P < 0.001). These results were largely influenced by anal squamous cell cancer and Hodgkin's lymphoma. The rate ratio for infection-unrelated NADC was 1.3 (95% CI: 1.2–1.4), with no change in the rate ratio over time (P = 0.44). Among infection-unrelated NADCs, other anal, skin, other head and neck, and lung cancer rates were higher and prostate cancer rates lower in HIV-infected persons. Among all infection-unrelated NADCs, the rate ratio decreased over time only for lung cancer (P = 0.007).
Conclusion: In comparison with those without HIV infection, HIV-infected persons are at particular risk for cancers with a known infectious cause, although the higher risk has decreased in the antiretroviral therapy era. Cancers without a known infectious cause are modestly increased in HIV-infected persons compared with HIV-uninfected persons.
aDivision of Research, Kaiser Permanente Northern California, Oakland, USA
bDepartment of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, USA
cKaiser Permanente Northern California, Hayward Medical Center, Hayward, USA
dKaiser Permanente Southern California, Los Angeles Medical Center, Los Angeles, USA
eHematology-Oncology Division, San Francisco General Hospital and University of California San Francisco, San Francisco, California, USA.
Received 2 April, 2009
Revised 23 July, 2009
Accepted 5 August, 2009
Correspondence to M.J. Silverberg, Division of Research, Kaiser Permanente Northern California, 2000 Broadway, Oakland, CA 94612, USA. Tel: +1 510 891 3801; fax: +1 510 891 3508; e-mail: Michael.J.Silverberg@kp.org