The effectiveness of chemotherapy for patients with pT3N0M0 renal pelvic urothelial carcinomas: An inverse probability of treatment weighting comparison using Surveillance, Epidemiology, and End Results data.

Introduction: Unlike the established evidence to use chemotherapy for urothelial carcinoma of the bladder, presently there are insufficient data to inform a recommendation on upper urinary tract urothelial carcinoma treatment. The prognosis for patients with stage T4 and positive lymph nodes is poor; however, primary tumors in the renal pelvis are associated with favorable prognoses compared to those located in the ureter. Our study aimed at investigating the effectiveness of chemotherapy in patients with pT3N0M0 renal pelvic urothelial carcinomas (RPUC) who have relative favorable prognosis.

Methods: Patients with pT3N0M0 tumors who underwent radical nephroureterectomy combined with bladder cuff excision between 2005 and 2014 and registered in the Surveillance, Epidemiology, and End Results database were eligible for inclusion (n = 939). Baseline characteristics between the chemotherapy and observation groups were controlled for with inverse probability of treatment weighting (IPTW)-adjusted analysis.

Results: After the IPTW-adjusted analysis, the 5-year IPTW-adjusted rates of overall survival (OS) for the chemotherapy and observation groups were 53.1% and 44.9%, respectively. The IPTW-adjusted Kaplan-Meier curves suggested that chemotherapy was associated with increased OS compared with observation (P = .028). In the IPTW-adjusted Cox proportional hazards regression model, chemotherapy was associated with favorable survival benefits compared with observation (hazard ratio [HR] 0.71, 95% CI 0.52-0.92, P = .031), and this was maintained after bootstrapping (HR 0.72, 95% CI 0.49-0.93). Chemotherapy had a protective effect on OS benefits, which were found in a majority of the results of the subgroup analysis and were consistent with the main results (all P-interactions > 0.05).

Conclusion: Chemotherapy may provide significant OS benefits for patients with pT3N0M0 RPUC. The results of our study could strengthen the evidence for using adjuvant chemotherapy in this rare group of patients.