Risk and Predictors of Esophageal and Stomach Cancers in HIV-Infected Veterans: A Matched Cohort Study

BACKGROUND:To evaluate the risks of esophageal and stomach carcinomas in people living with HIV (PLWH) compared with the general population and risk factors for these cancers in PLWH. SETTING:Retrospective cohort study in the Veterans Health Administration. METHODS:We compared incidence rates for esophageal and stomach cancers in 44,075 HIV-infected male veterans with those in a matched HIV-uninfected cohort (N = 157,705; 4:1 matched on age and HIV-index date). We used Cox regression models to estimate Hazard ratios (HRs) and 95% confidence intervals (CIs) for associations with HIV infection and for cancer risk factors in PLWH. RESULTS:In unadjusted models, HIV infection was associated with increased risks of esophageal squamous cell carcinoma (ESCC; HR, 2.21; 95% CI1.47 to 3.13) and gastric cardia cancer (HR, 1.69; 95% CI1.00 to 2.85) but associated with lower risk of esophageal adenocarcinoma (EAC; HR, 0.48; 95% CI0.31 to 0.74). After adjusting for age, race/ethnicity, smoking and alcohol use, HIV infection remained statistically significantly associated with elevated risk for ESCC [adjusted hazard ratio (aHR), 1.58; 95% CI1.02 to 2.47], especially among HIV-infected patients with CD4 count ≤200 (aHR, 2.20; 95% CI1.35 to 3.60). HIV infection was not associated with risks of EAC (aHR, 0.82; 95% CI0.53 to 1.26), gastric cardia (aHR, 0.80; 95% CI0.33 to 1.94), or noncardia (aHR, 1.06; 95% CI0.61 to 1.84) cancers. Risk factors for these cancers in HIV-infected patients were otherwise similar to those in general population (eg, Helicobacter pylori for gastric noncardia cancer). CONCLUSION:HIV-infected individuals with low CD4 count are at highest risk for ESCC, but HIV infection was not independently associated with EAC or gastric cancer after adjusting for confounders.