Implications for Efficacy and Safety of Total Dose and Dose-Intensity of Neoadjuvant Gemcitabine-Cisplatin in Muscle-Invasive Bladder Cancer: Three-Week Versus Four-Week Regimen.

Background: Neoadjuvant cisplatin-based chemotherapy is standard care prior to radical cystectomy in patients with muscle-invasive bladder cancer (MIBC).

Objective: To assess efficacy and safety of two commonly used neoadjuvant schedules with different total doses and dose-intensities of gemcitabine and cisplatin (GC).

Methods: Data were collected retrospectively from all patients treated between 2010 and 2018 with neoadjuvant chemotherapy according to clinical routine at seven centres in Sweden and Denmark. Patients in Sweden received three cycles of a 4-week schedule (GC-4w: cisplatin 70 mg/m² day 1, gemcitabine 1000 mg/m² days 1, 8, 15, q 28 days) and in Denmark four cycles of a 3-week schedule (GC-3w: cisplatin 70 mg/m² day 1, gemcitabine 1000 mg/m² days 1, 8, q 21 days). Primary endpoint was pathological response at cystectomy (pT0N0 and < pT2N0).

Results: A total of 251 patients were treated with GC-4w and 455 with GC-3w. pT0N0 was significantly higher for patients treated with GC-3w compared to GC-4w, 46% versus 32% (adjusted odds ratio [aOR] 1.80; 95% confidence interval [CI] 1.16-2.80; P = 0.009); and for < pT2N0 60% versus 47% (aOR 1.08; 95% CI 0.70-1.66; P = 0.743). There were no significant differences between GC-4w and GC-3w regarding survival parameters. GC-3w patients discontinued treatment more frequently and showed a higher degree of neutropenia.

Conclusions: A significantly higher complete response-rate was observed in the patient group treated with the more cisplatin-dose-intense 3-week schedule. The side-effect profile was in favor of the 4-week approach while relapse-free and overall survival were similar.