Active surveillance in renal transplant patients with prostate cancer: a multicentre analysis

Introduction: Due to medical improvements leading to increased life expectancy after renal transplantation and widened eligibility criteria allowing older patients to be transplanted, incidence of (low-risk) prostate cancer (PCa) is increasing among renal transplant recipients (RTR). It remains to be established whether active surveillance (AS) for PCa represents a safe treatment option in this setting. Therefore, we aim to compare AS discontinuation and oncological outcomes of AS for PCa of RTR vs. non-transplant patients. Methods: Multicentre study including RTR diagnosed with PCa between 2008 and 2018 in whom AS was initiated. A subgroup of non-RTR from the St. Antonius hospital AS cohort was used as a control group. Comparison of RTR vs. non-RTR was performed by 2:1 propensity score matched survival analysis. Outcome measures included tumour progression-free survival, treatment-free survival, metastasis rates, biochemical recurrence rates and overall survival. Patients were matched based on age, year of diagnosis, PSA, biopsy ISUP grade group, relative number of positive biopsy cores and clinical stage. Results: A total of 628 patients under AS were evaluated, including 17 RTRs and 611 non-RTRs. A total of 13 RTR cases were matched with 24 non-RTR cases. Median overall follow-up for the RTR and non-RTR matched cases was, respectively, 5.1 (IQR 3.2–8.7) years and 5.7 (IQR 4.8–8.1) years. There were no events of metastasis and biochemical recurrence among matched cases. The matched-pair analysis results in a 1-year and 5-year survival of the RTR and non-RTR patients were, respectively, 100 vs. 92%, and 39 vs. 76% for tumour progression, 100 vs. 91% and 59 vs. 76% for treatment-free survival and, respectively, 100 vs. 100% and 88 vs. 100% for overall survival. No significant differences in tumour progression-free survival (p = 0.07) and treatment-free survival were observed (p = 0.3). However, there was a significant difference in overall survival comparing both groups (p = 0.046). Conclusions: AS may be carefully considered in RTR with low-risk PCa. In our preliminary analysis, no major differences were present in AS outcomes between RTR and non-RTR. Overall mortality was significantly higher in the RTR subgroup.