The benefit of a neoadjuvant instillation of chemotherapy in non-muscle invasive bladder cancer: Interim analysis of the PRECAVE randomized clinical trial

Although an immediate postoperative instillation of chemotherapy (IPOIC) after transurethral resection of bladder tumors (TURBT) is recommended for the prevention of recurrences of non-muscleinvasive bladder cancer (NMIBC), evidence shows there is an important compliance failure worldwide. We believe that an immediate neoadjuvant instillation of chemotherapy (INAIC) can act similarly, reducing the recurrence risk of NMIBC. Here we present the interim analysis of the PRECAVE clinical trial. Patients with clinically diagnosed NMIBC were randomized to receive an INAIC with mitomycin C before TURBT (Group A) or to a control group with TURBT only (Group B). Primary end point was to compare the efficacy of an INAIC in the early recurrence-free survival (RFS). Secondary end points were: RFS in patients who did not receive adjuvant treatments, toxicity, and feasibility. A total of 124 patients with Ta/T1 G1-G3NMIBC were included in the initial analysis (Group A:64, Group B: 60). Demographics, risk classification, complications, and adjuvant treatments were balanced between groups. Eighty-four patients (Group A: 45, Group B: 39) who completed a one-year follow-up were included in the efficacy analysis and no difference was observed in the RFS between groups (p=0.3). In the subgroup of patients who did not receive adjuvant treatments, we found a significant difference in favor of an INAIC (p=0.009) and an 80% reduction in the risk of early recurrences (Hazard Ratio: 0.20; 95% confidence interval: 0.05-0.81; p=0.0024). No differences were observed in adverse events. Only 4 patients did not receive an INAIC despite being planned. In this interim analysis, although we could not demonstrate a reduction in the RFS of all patients, we did find a significant decrease of recurrences in patients who did not receive adjuvant treatments. The administration of an INAIC seems to be safe and our protocol appears feasible and reproductive.