Cancer‐attributable mortality among solid organ transplant recipients in the United States: 1987 through 2014

Background Solid organ transplant recipients have an elevated risk of cancer. Quantifying deaths attributable to cancer can inform priorities to reduce cancer burden. Methods Linked transplantation and cancer registry data were used to identify incident cancers and deaths among solid organ transplant recipients in the United States (1987‐2014). Population‐attributable fractions (PAFs) of deaths due to cancer and corresponding cancer‐attributable mortality rates were estimated using Cox models. Results Among 221,962 solid organ transplant recipients, 15,012 developed cancer. Approximately 13% of deaths (PAF, 13.2%) were attributable to cancer, corresponding to a cancer‐attributable mortality rate of 516 per 100,000 person‐years. Lung cancer was the largest contributor to mortality (PAF, 3.1%), followed by non‐Hodgkin lymphoma (NHL; PAF, 1.9%), colorectal cancer (PAF, 0.7%), and kidney cancer (PAF, 0.5%). Cancer‐attributable mortality rates increased with age at transplantation, reaching 1229 per 100,000 person‐years among recipients aged ≥65 years. NHL was the largest contributor among children (PAF, 4.1%) and lung cancer was the largest contributor among recipients aged ≥50 years (PAFs, 3.7%‐4.3%). Heart recipients had the highest PAF (16.4%), but lung recipients had the highest cancer‐attributable mortality rate (1241 per 100,000 person‐years). Overall, mortality attributable to cancer increased steadily with longer time since transplantation, reaching 15.7% of deaths (810 per 100,000 person‐years) at ≥10 years after transplantation. Comparison of cancer‐attributable mortality rates with specified causes of death indicated that some deaths recorded as other causes might instead be caused by cancer or its treatment. Conclusions Cancer is a substantial cause of mortality among solid organ transplant recipients, with major contributions reported from lung cancer and NHL. Cancer‐attributable mortality increases with age and time since transplantation, and therefore cancer deaths will become an increasing burden as recipients live longer.