Incremental Utility of Adjuvant Chemotherapy in Muscle-invasive Bladder Cancer: Quantifying the Relapse Risk Associated with Therapeutic Effect.

The availability of new potent systemic therapies for urothelial carcinoma may change the way we use standard chemotherapy perioperatively. In particular, identifying which patients with muscle-invasive bladder cancer (MIBC) would benefit from adjuvant chemotherapy (AC) is compelling. From a multicenter database we selected 950 patients with cT2-4N0M0 MIBC treated with radical cystectomy (RC), with or without neoadjuvant chemotherapy (NAC), and AC. We used Kaplan-Meier analyses to test 1-yr recurrence-free survival (RFS) rates according to AC use. Nomogram-derived probabilities of 1-yr recurrence after RC were plotted against actual recurrence rates according to AC use. Overall, we did not see evidence of an AC effect on the 1-yr RFS rate (p=0.6). Conversely, the 1-yr RFS rate was higher among patients with pT3-4 or pN1 disease who received AC (75% vs 54%; p<0.001). We were unable to demonstrate a difference between AC and no AC among patients who received prior NAC (1-yr RFS 57% vs 76%; p=0.057). As the most important finding, AC was associated with incremental RFS benefits only for patients with a nomogram-derived 1-yr recurrence probability of >40%. Patient summary: Maximizing disease control with adjuvant chemotherapy was beneficial for patients with muscle-invasive bladder cancer who had a calculated recurrence risk of >40% and did not impact cancer recurrence in lower-risk disease. Therefore, patient stratification using the nomogram available for predicting recurrence is advisable pending external validation.