Introduction:

Transplanted patients who develop localized renal cell carcinoma (RCC) have a theoretically higher risk of disease progression because of pharmacologic immunosuppression. This study compared outcomes for localized RCC patients who received a prior organ transplant to a matched cohort of non-transplant patients.

Methods:

Patients with tissue diagnosis of non-metastatic RCC after transplantation between 2000 and 2020 were identified from a solid organ transplant database. Transplanted patients were matched 1:2 to non-transplanted patients based on treatment type, age, grade, and tumor size. Clinical variables and survival outcomes were compared.

Results:

A total of 81 patients were identified who developed non-metastatic RCC after organ transplant. The median age was 57 years, and 27% were female. Management strategies included surgery (65%), thermal ablation (23%), and active surveillance (10%). Among active surveillance patients, 0/9 developed metastases, and 4/9 died not due to RCC, with a median follow-up of 89 months. Papillary RCC was more common in the transplant than in matched cohorts (41 vs 18%, P<0.001).

Among ablation patients, the median follow-up was 60 vs. 34 months for transplant vs. non-transplant patients (N=19, 43); P=0.002 (Figure 1A). No differences were found in 90-day complications, local recurrence, metastatic progression, or overall survival between transplant and non-transplant patients (P>0.05 for all) (Figure 2A).

Among surgical patients, median follow-up was 65 vs 90 months for transplant vs. non-transplant patients (N=54, 104); P=0.08. Transplant patients were more likely to have postoperative complications (P=0.04) (Figure 1B). No difference was found in local recurrence, metastatic progression, or overall survival (P>0.05 for all) (Figure 2B)

Among all patients, multivariable Cox regression showed that only the Charlson comorbidity index was significantly associated with mortality (HR 1.3, P<0.001) after adjusting for transplant status, age, grade, RCC subtype, and tumor size.

Conclusion:

Patients who develop non-metastatic RCC after solid organ transplantation have similar outcomes as non-transplant patients. Mortality is primarily associated with comorbidity, and further studies should evaluate expanding the role of active surveillance for transplant patients with localized RCC.

Funding: N/A