Comparison of survival outcomes between kidney transplant and dialysis in patients with previous cancer.

BACKGROUND The number of cancer survivors that develop kidney failure is increasing. However, there is a lack of evidence supporting clinicians offering kidney transplant or dialysis when facing a kidney failure patient with a previous cancer history. METHODS This retrospective observational cohort study was conducted using the Inner Mongolia Regional Health Information Platform. Patients who underwent kidney transplantation or dialysis with a preexisting cancer diagnosis between January 1, 2012, and December 31, 2021, were included. We used overall mortality as the primary outcome, and cancer-specific mortality as the secondary outcome. RESULTS A total of 170,414 patients diagnosed with cancer were identified, out of which 1762 patients started kidney replacement therapy (KRT) after the cancer diagnosis, 5.45% (n = 96) accepted kidney transplants and 94.55% (n = 1666) underwent dialysis. Females tended to be less likely to commence kidney transplantation (odds ratio [OR] = 0.381, 95% confidence interval [CI]: 0.237-0.602). During a median follow-up of 3.19 (interquantile range [IQR] = 1.37-5.13) years, 566 (32.12%) deaths were recorded. The overall mortality rate (18.75% vs. 32.89%, P = 0.006) was lower in the kidney transplant group than in the dialysis group. After adjusting for sex, age, ethnicity, KRT start year, residency economic level, insurance type, cancer type, and cancer stage, kidney transplantation was associated with decreased overall mortality (hazard ratio [HR] = 0.542, 95% CI: 0.338-0.871, P = 0.011) compared with dialysis. These results were consistent after propensity score matching. The difference in cancer-specific mortality (10.42% vs. 17.59%, P = 0.095) and annual medical costs ($10,016.37 vs. $10,977.18, P = 0.982) between transplant and dialysis were statistically insignificant. CONCLUSIONS In patients with prior cancer diagnoses, kidney transplantation showed better overall survival, similar cancer-specific survival outcomes, and cost-effectiveness than dialysis. Our findings add survival and cost data for KRT and provide evidence for stakeholders to consider the KRT mode in patients with a history of cancer.