Cancer incidence in a nationwide HIV/AIDS Patient Cohort in Taiwan in 1998-2009

Background: The aims of this study were to investigate the cancer incidence and risk in HIV/AIDS patients relative to the general population in Taiwan. Methods: Using Taiwan's National Health Insurance Research Database, 15,269 HIV/AIDS patients were identified between 1998 and 2009. Gender-specific incidence densities (IDs) of both AIDSdefining cancers (ADC) and non-AIDS-defining cancers (NADC) after HIV infection were calculated. Age-, sex-, and periodadjusted standardized incidence rates (SIRs) were obtained using 1.8 million people from the general population as controls. Results: A total of 1117 male and 165 female HIV/AIDS patients were diagnosed with cancer. Non-Hodgkin lymphoma (n = 196; ID = 328.79/100,000 person-years) and cervical cancer (n = 50; ID = 712.08/100,000 person-years) were the most common ADCs, whereas liver cancer (n = 125; ID = 184.52/100,000 person-years) and colon cancer (n = 11; ID = 156.66/100,000 person-years) were the most common NADCs in males and females, respectively. Period-adjusted gender-specific ADC and NADC rates decreased from more than 1500 cases/100,000 person-years to less than 500 cases/100,000 person-years (P > 0.001 for trend). SIRs of ADCs and NADCs also decreased. However, relative to the general population, increased SIRs were still seen for most cancers, many of which had an infectious etiology. The highest SIRs in ADCs and NADCs were seen in Kaposi sarcoma [SIR = 298.0, 95% confidence interval (CI): 258.16 to 343.85] and anal cancer (SIR = 19.10, 95% CI: 12.80 to 27.50). Conclusion: This study showed that although the cancer incidence rates have significantly decreased in the highly active antiretroviral therapy era, HIV/AIDS patients were still at increased risk of ADCs and most NADCs. Cancer screening, especially for infection-related NADCs, should therefore be promoted.