Background: Combination antiretroviral therapy (cART) may reduce cancer risk among people with HIV (PWH), but cancer-specific associations are incompletely understood.
Methods: We linked HIV and cancer registries in Texas to a national prescription claims database. cART use was quantified as the proportion of days covered (PDC). Cox proportional hazards models assessed associations of cancer risk with cART usage, adjusting for demographic characteristics, AIDS status, and time since HIV report.
Results: We evaluated 63 694 PWH followed for 276 804 person-years. The median cART PDC was 21.4% (interquartile range: 0.0-59.8%). cART use was associated with reduced risk of Kaposi sarcoma [adjusted hazard ratio (aHR) 0.48, 95% confidence interval (CI) 0.34-0.68 relative to unexposed status] and non-Hodgkin lymphoma (aHR 0.41, 95% CI 0.31-0.53), liver cancer (aHR 0.61, 95% CI 0.39-0.96), anal cancer (aHR 0.65, 95% CI 0.46-0.92), and a miscellaneous group of 'other' cancers (aHR 0.80, 95% CI 0.66-0.98). In contrast, cART-exposed status was not associated with risk for cervical, lung, colorectal, prostate or breast cancers.
Conclusion: In a large HIV cohort incorporating data from prescription claims, cART was associated with greatly reduced risks of Kaposi sarcoma and non-Hodgkin lymphoma, and to a lesser degree, reduced risks of liver and anal cancers. These associations likely reflect the beneficial effects of HIV suppression and improved immune control of oncogenic viruses. Efforts to increase cART use and adherence may further decrease cancer incidence among PWH.