Lifestyle behaviors and site-specific cancer risk after kidney transplantation: age- and comorbidity-related differences in a nationwide cohort

Kidney transplant recipients (KTRs) have an increased cancer risk, but the influence of lifestyle factors remains unclear. This study investigated how smoking, alcohol, and physical activity affect post-transplant malignancy. We assembled a nationwide cohort of KTRs using health screening data. The primary outcome was incidence of malignancy 1 year after transplantation. The secondary outcomes were all-cause mortality and graft failure. Overall cancer incidence was not significantly associated with smoking, alcohol consumption, or physical activity in the fully adjusted models. Site-specific analyses revealed that smoking was associated with lung cancer (current vs. never: hazard ratio [HR], 5.94; 95% confidence interval [CI], 2.06–17.09). Alcohol consumption was associated with esophageal cancer (yes vs. no: HR, 7.41; 95% CI, 1.20–45.67). Age strengthens these associations. Among KTRs with diabetes, current smoking was linked to higher risks of colorectal (HR 3.09) and pancreatic (5.81) cancer. Although physical activity was not associated with cancer incidence, it was associated with lower mortality rates (HR, 0.72; 95% CI, 0.61–0.85). Lifestyle factors had a limited impact on the overall cancer incidence; however, significant site-specific or subgroup associations were evident. These results support smoking cessation, alcohol consumption reduction, and routine exercise in improving the survival of KTRs.