Three versus four cycles of neoadjuvant chemotherapy for muscle-invasive bladder cancer: a systematic review and meta-analysis

The optimal cycle of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) remains controversial. This study aimed to compare the efficacy of three and four cycles of NAC in the treatment of MIBC through a systematic review and meta-analysis of the literature. Relevant studies were systematically collected and reviewed in PubMed, Medline, Embase, Web of Science Databases, and the Cochrane Library. Relative ratios (RRs), Hazard ratios (HRs) and their 95% confidence intervals (CIs) were used to estimate outcome measures. Studies comparing the pathological response and prognosis of three versus four cycles of NAC for MIBC were included. Five studies were included in this meta-analysis, including 2190 patients, of whom 1016 underwent three cycles of NAC and 1174 underwent four cycles of NAC. All studies were retrospective cohort studies. We found that 4 cycles of NAC had significantly better cancer-specific survival than 3 cycles (HR = 1.31, 95%CI,1.03-1.67, = 0.029). There was no significant difference in overall survival between patients who received 3 and 4 cycles of chemotherapy (HR = 1.18, 95%CI = 0.83-1.69, = 0.345). Similarly, no significant difference was observed in pathological objective response (RR = 0.95, 95%CI= 0.81-1.11, = 0.515) and complete response rates (RR = 0.87, 95%CI = 0.69-1.11, = 0.256) in MIBC after 3 or 4 cycles of NAC. Three and four cycles of NAC had similar pathological responses and prognosis for MIBC, although the cancer-specific survival rate of four cycles was better than that of three cycles.