HIV Infection, Immunosuppression, and Age at Diagnosis of Non-AIDS-Defining Cancers

Abstract

Background: It is unclear whether immunosuppression leads to younger ages at cancer diagnosis among people living with human immunodeficiency virus (PLWH). A previous study found that most cancers are not diagnosed at a younger age in people with AIDS, with the exception of anal and lung cancers. This study extends prior work to include all PLWH and examines associations between AIDS, CD4 count, and age at cancer diagnosis.

Methods: We compared the median age at cancer diagnosis between PLWH in the North American AIDS Cohort Collaboration on Research and Design and the general population using data from the Surveillance, Epidemiology and End Results Program. We used statistical weights to adjust for population differences. We also compared median age at cancer diagnosis by AIDS status and CD4 count.

Results: After adjusting for population differences, younger ages at diagnosis (P < .05) were observed for PLWH compared with the general population for lung (difference in medians = 4 years), anal (difference = 4), oral cavity/pharynx (difference = 2), and kidney cancers (difference = 2) and myeloma (difference = 4). Among PLWH, having an AIDS-defining event was associated with a younger age at myeloma diagnosis (difference = 4; P = .01), and CD4 count <200 cells/µL (vs ≥500) was associated with a younger age at lung cancer diagnosis (difference = 4; P = .006).

Conclusions: Among PLWH, most cancers are not diagnosed at younger ages. However, this study strengthens evidence that lung cancer, anal cancer, and myeloma are diagnosed at modestly younger ages, and also shows younger ages at diagnosis of oral cavity/pharynx and kidney cancers, possibly reflecting accelerated cancer progression, etiologic heterogeneity, or risk factor exposure in PLWH.

Keywords: AIDS; HIV; aging; cancer; immunosuppression.

Figure 1.

Fraction of total person-time in the human immunodeficiency virus (HIV)-infected population (North American AIDS Cohort Collaboration on Research and Design [NA-ACCORD]) and the general population (Surveillance Epidemiology and End Results [SEER-13]) by single year of age, 1996–2008. Person-time in the HIV-infected population (NA-ACCORD, gray bars) and the general population (SEER-13, black bars). Bars represent the fraction of person-time contributed by each single year of age from 20 to 79 years old.

Figure 2.

Standardized incidence ratios (SIRs) comparing cancer risk in human immunodeficiency virus-infected people to the general population across age groups for lung cancer (A), anal cancer (B), oral cavity and pharynx cancers (C), kidney cancer (D), and myeloma (E). Points represent SIRs and lines represent 95% confidence intervals (CIs). SIRs were standardized by age, sex, race, and calendar period. No point is presented for 70- to 79-year-olds in the myeloma figure, as there were no observed cases (SIR, 0 [95% CI, 0–.88]).

Figure 3.

Median age at cancer diagnosis by AIDS status (A) and CD4 cell counts (B) for lung cancer, anal cancer, oral cavity and pharynx cancers, kidney cancer, and myeloma in human immunodeficiency virus (HIV)-infected people. Points represent median ages at diagnosis and lines represent 95% confidence intervals (CIs). Asterisks indicate statistically significant differences in weighted median ages (p<0.05). All estimates were standardized to the full North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) population by single year of age, race, and calendar period. The adjusted median ages at diagnosis for people living with HIV with a missing CD4 cell count were 44 years (95% CI, 43–46) for anal cancer, 50 years (95% CI, 46.5–53.0) for kidney cancer, 54 years (95% CI, 53–55.2) for lung cancer, 53 years (95% CI, 49.2–57.5) for myeloma, and 51 years (95% CI, 48.4–53) for oral cavity/pharynx cancer.