Background: Immunosuppressed individuals have elevated risk of virus-related cancers. Identifying cancers with elevated risk in people with HIV and solid organ transplant recipients, 2 immunosuppressed populations, may help identify novel etiologic relationships with infectious agents.
Methods: We used 2 linkages of population-based cancer registries with HIV and transplant registries in the United States. Cancer entities were systematically classified according to site and histology codes. Standardized incidence ratios were used to compare risk in people with HIV and solid organ transplant recipients with the general population. For selected cancer entities, incidence rate ratios were calculated for indicators of immunosuppression within each population.
Results: We identified 38 047 cancer cases in solid organ transplant recipients and 53 592 in people with HIV, yielding overall standardized incidence ratios of 1.66 (95% confidence interval [CI] = 1.65 to 1.68) and 1.49 (95% CI = 1.47 to 1.50), respectively. A total of 43 cancer entities met selection criteria, including conjunctival squamous cell carcinoma (people with HIV standardized incidence ratio = 7.1, 95% CI = 5.5 to 9.2; solid organ transplant recipients standardized incidence ratio = 9.4, 95% CI = 6.8 to 12.6). Sebaceous adenocarcinoma was elevated in solid organ transplant recipients (standardized incidence ratio = 16.2, 95% CI = 14.0 to 18.6) and, among solid organ transplant recipients, associated with greater risk in lung and heart transplant recipients compared with recipients of other organs (incidence rate ratio = 2.3, 95% CI = 1.7 to 3.2). Salivary gland tumors, malignant fibrous histiocytoma, and intrahepatic cholangiocarcinoma showed elevated risk in solid organ transplant recipients (standardized incidence ratio = 3.9, 4.7, and 3.2, respectively) but not in people with HIV. However, risks for these cancers were elevated following an AIDS diagnosis among people with HIV (incidence rate ratio = 2.4, 4.3, and 2.0, respectively).
Conclusions: Elevated standardized incidence ratios among solid organ transplant recipients and people with HIV, and associations with immunosuppression within these populations, suggest novel infectious causes for several cancers including conjunctival squamous cell carcinoma, sebaceous adenocarcinoma, salivary gland tumors, malignant fibrous histiocytoma, and intrahepatic cholangiocarcinoma.
Published by Oxford University Press 2024.