Tumor characteristics in immunosuppressed and renal dysfunction populations

Renal transplantation and end-stage renal disease are increasingly common. Renal dysfunction and immunosuppression are two risk factors in the development of renal cell carcinoma. Carcinomas in these patients are thought to be more indolent, however data are limited and mixed. Our objective was to describe the histology of resected tumors from the transplant and renal dysfunction population and compare them to a control population.

This was a single-center retrospective cohort study of all patients who had a nephrectomy for a renal mass from 2009 to 2019. All transplant status and end-stage renal disease diagnoses were identified by diagnostic or procedural coding and confirmed by chart review. Our primary endpoint was the pathology for each patient's tumor. Tumors were classified into aggressive or nonaggressive categories based on their histology and grade.

We identified 1,150 radical and partial nephrectomies, of which 1,057 met inclusion criteria. Of these, 68 patients (6.4%) had renal dysfunction or a kidney transplant on immunosuppression at time of nephrectomy. After pathologic review, 270 (25%) tumors were classified as aggressive, and 673 (64%) tumors were pT1a or pT1b. On multivariable logistic regression controlling for age and gender, renal dysfunction was not associated with having an aggressive tumor (OR 1.24, 95%CI 0.72-2.15; P = 0.44).

We did not observe a relationship between renal dysfunction status and aggressive pathology. These data suggest that renal dysfunction and transplant patients are at similar risk for aggressive pathology as the general population and should be managed according to the same clinical guidelines.