Induction and maintenance of sequential intravesical gemcitabine/docetaxel for intermediate and high-risk non-muscle invasive bladder cancer with different dosage protocols.

INTRODUCTION: The combination of sequential intravesical gemcitabine and docetaxel (Gem/Doce) chemotherapy has been considered a feasible option for BCG (Bacillus Calmette-Guérin) treatment in non-muscle invasive bladder cancer (NMIBC), gaining popularity during BCG shortage period. We seek to determine the efficacy of the treatment by comparing Gem/Doce induction alone vs induction with maintenance, and to evaluate the treatment outcomes of two different dosage protocols. METHODS: A bi-center retrospective analysis of consecutive patients treated with Gem/Doce for NMIBC between 2018 and 2023 was performed. Baseline characteristics, risk group stratification (AUA 2020 guidelines), pathological, and surveillance reports were collected. Kaplan-Meier survival analysis was performed to detect Recurrence-free survival (RFS). RESULTS: Overall, 83 patients (68 males, 15 females) with a median age of 73 (IQR 66-79), and a median follow-up time of 18 months (IQR 9-25), were included. Forty-one had an intermediate-risk disease (49%) and 42 had a high-risk disease (51%). Thirty-seven patients (45%) had a recurrence; 19 (23%) had a high-grade recurrence. RFS of Gem/Doce induction-only vs induction + maintenance was at 6 months 88% vs 100%, at 12 months 71% vs 97%, at 18 months 57% vs 91%, and at 24 months 31% vs 87%, respectively (log-rank, p < 0.0001). Patients who received 2 g Gemcitabine with Docetaxel had better RFS for all-grade recurrences (log-rank, p = 0.017). However, no difference was found for high-grade recurrences. CONCLUSION: Gem/Doce induction with maintenance resulted in significantly better RFS than induction-only. Combining 2 g gemcitabine with docetaxel resulted in better RFS for all-grade but not for high-grade recurrences. Further prospective trials are necessary to validate our results.