Comparison of 3 and 4 cycles of neoadjuvant gemcitabine and cisplatin for muscle-invasive bladder cancer: a systematic review and meta-analysis

BACKGROUND: In muscle-invasive bladder cancer (MIBC), neoadjuvant chemotherapy (NAC) combined with radical cystectomy (RC) is critical in reducing disease recurrence, with GC (gemcitabine and cisplatin) being one of the most commonly used NACs. Different GC schedules have been used, but the best neoadjuvant regimen is still unknown. The clinical outcomes of 3 and 4 cycles of neoadjuvant GC are compared in this systematic review and meta-analysis to determine which is best for patients with MIBC. METHODS: We searched PubMed, Embase, Web of Science, Cochrane Library, CBM, CNKI, WAN FANG DATA, and meeting abstracts to identify relevant studies up to March 2023. Studies that compared 3 and 4 cycles of neoadjuvant GC for MIBC were included. The primary outcomes were pCR, pDS, OS, and CSS. The secondary outcome was recurrence and SAEs. RESULTS: A total of 3 studies, with 1091 patients, were included in the final analysis. Patients that received 4 cycles of GC had a higher pCR (OR = 0.66; 95% CI, 0.50–0.87; p = 0.003) and pDS (OR = 0.63; 95% CI, 0.48–0.84; p = 0.002) than those who received 3 cycles. Regarding recurrence rate (OR = 1.23; 95% CI, 0.91–1.65; p = 0.18), there were no appreciable differences between the 3 and 4 cycles of GC. Survival parameters such as OS (HR, 1.35; 95% CI, 0.86–2.12; p = 0.19) and CSS (HR, 1.06; 95% CI, 0.82–1.38; p = 0.20) were similar. Only one trial reported on the outcomes of SAEs. And there were no statistically significant differences in thrombocytopenia, infection rate, neutropenic fever, anemia, or decreased renal function between patients. The neutropenia of patients was statistically different (OR = 0.72; 95% CI, 0.52–0.99; p = 0.04). CONCLUSION: The 4-cycle GC regimen was superior to the 3-cycle regimen in only the pCR and pDS results. Survival and recurrence rates were similar between the two regimens. In both treatment regimes, the toxicity profile was manageable. However, due to the inherent drawbacks of retrospective research, this should be regarded with caution.