OBJECTIVE: Males have a higher incidence of most non-reproductive cancers than females, which has often been attributed to differences in lifestyle or behaviors. We examined whether sex differences in cancer incidence are attenuated among immunocompromised adults. METHODS: Using data from population-based linkage study of HIV and cancer registries (2001-2019), we estimated male-to-female incidence rate ratios (M:F IRRs) among people with HIV (PWH) for 20 cancer sites. We used Poisson regression to adjust for age, race/ethnicity, calendar year, HIV transmission category, and HIV diagnosis year. We compared the M:F IRRs among PWH (M:F IRRPWH) to M:F IRRs in the general population (M:F IRRGP) with a chi-square test. RESULTS: PWH contributed 3,956,838 person-years of follow-up (53.6% among males, 46.4% among females). The M:F IRRPWH was significantly attenuated compared to the M:F IRRGP for 9 cancer sites: tongue (M:F IRRPWH 1.39 vs. M:F IRRGP 2.94; P<0.0001), oropharynx (1.80 vs 4.74; P<0.0001), esophagus (1.36 vs 3.43; P<0.0001), colon (0.90 vs 1.19; P=0.0002), liver (2.20 vs 4.22; P < 0.0001), larynx (1.50 vs 4.32; P<0.0001), lung (0.92 vs 1.39; P < 0.0001), bladder (1.21 vs 3.02; P<0.0001), and diffuse large B-cell lymphoma (1.35 vs 1.65; P<0.0001). Hodgkin lymphoma was the only site where the M:F IRRPWH was significantly larger than the M:F IRRGP (1.96 vs 1.45; P=0.0001). CONCLUSIONS: Although the incidence of most cancers remained higher among male than female PWH, the sex difference was attenuated among PWH for 9 cancers, suggesting that important immune differences between males and females in the general population contribute to differences in cancer incidence.
Maclin et al. (Thu,) studied this question.