Disparities and Determinants of Cancer Treatment in Elderly Americans Living With Human Immunodeficiency Virus/AIDS.

Background: Previous studies suggest that human immunodeficiency virus (HIV)-infected cancer patients are less likely to receive cancer treatment. The extent to which this disparity affects the growing population of elderly individuals is unknown and factors that mediate these treatment differences have not been explored.
Methods: We studied 930359 Americans aged 66-99 years who were diagnosed with 10 common cancers. Surveillance, Epidemiology, and End Results-Medicare claims from 1991 to 2011 were used to determine HIV status and receipt of cancer treatment in 6 months following diagnosis. Mediation analysis was conducted to estimate the direct effect of HIV, and indirect effect through cancer stage at diagnosis and comorbidities, on cancer treatment.
Results: HIV-infected individuals (n = 687) were less likely to receive cancer treatment (70% vs 75% HIV uninfected; P < .01). This difference was larger in individuals aged 66-70 years, among whom only 65% were treated (vs 81% in HIV uninfected; P < .01), and time from cancer diagnosis to treatment was longer (median, 42.5 vs 36 days in HIV uninfected; P < .01). Accounting for potential confounders, HIV-infected individuals aged 66-70 years remained 20% less likely to receive cancer treatment (hazard ratio, 0.81 [95% confidence interval, .71-.92]). Seventy-five percent of this total effect was due to HIV itself, with a nonsignificant 24% mediated by cancer stage and comorbidities. Conclusions: Lowest cancer treatment rates were seen in the younger subset of HIV-infected individuals, who would likely benefit most from treatment in terms of life expectancy.