Clinical impact of carboplatin-based neoadjuvant chemotherapy: lack of benefit and surgical delay in muscle-invasive bladder cancer

Cisplatin-based neoadjuvant chemotherapy (NAC) improves outcomes in muscle-invasive bladder cancer (MIBC), whereas the efficacy of carboplatin-based or suboptimal regimens remains unclear. We retrospectively reviewed 265 patients who underwent radical cystectomy, including 164 with MIBC. Among them, 21 received ≥3 cycles of gemcitabine/cisplatin (optimal NAC), 44 received ≤2 cycles of cisplatin-based NAC, 36 received gemcitabine/carboplatin (GCarb) NAC, and 63 underwent cystectomy alone. Propensity score matching was applied to compare the GCarb and no-NAC cohorts based on clinical stage, performance status, and renal function. The pathological complete response rate did not differ between the groups. Disease-free survival tended to be worse in the GCarb cohort (P = .07). Importantly, the median time-to-cystectomy from diagnosis with MIBC was significantly longer with GCarb than no-NAC cohort (3.1 vs. 1.5 months). These findings suggest that GCarb-based NAC may be detrimental by delaying surgery without providing oncological benefit, reinforcing guideline recommendations against its use in MIBC.