Meta-analysis of neoadjuvant chemotherapy compared to radical cystectomy alone in improving overall survival of muscle-invasive bladder cancer patients

Background Most patients with muscle-invasive bladder cancer (MIBC) developed metastasis within 2 years, even after radical cystectomy (RC). The recurrence rate of MIBC was more than 50% of the cases. A meta-analysis conducted by Yin et al. showed that neoadjuvant chemotherapy (NAC) + RC improves overall survival in MIBC compared with RC only. However, a new meta-analysis by Li et al. concluded that NAC + RC was not superior to RC only in improving overall survival. The inconsistencies of these studies required further comprehensive analysis to recommend NAC use in bladder cancer treatment. Therefore, this meta-analysis aims to analyze previous studies that compare the efficacy of NAC + RC versus RC only to improve overall survival of MIBC. Methods The articles were searched using Pubmed with keywords "muscle-invasive bladder cancer", "neoadjuvant chemotherapy", "cystectomy", and "overall survival". The articles that were published until June 2020 were screened. The overall survival outcome was analyzed as hazard ratio (HR) and presented in a forest plot. Result Seventeen studies were included in meta-analysis with a total sample of 13,391 patients, consist of 2890 received NAC followed by RC and 10,418 underwent RC only. Two studies used methotrexate/vinblastine/doxorubicin/cisplatin (MVAC), two studies used gemcitabine/cisplatin (GC), one study used Cisplatin-based regimen, one study used MVAC or GC, one study used gemcitabine/carboplatin (GCarbo) or GC or MVAC, one study used Cisplatin/Gemcitabine or MVAC, one study used Cisplatin only, one study used Cisplatin-based (GC, MVAC) or non-Cisplatin-based (combined paclitaxel/gemcitabine/carboplatin), one study used GC, MVAC, Carboplatin, or Gemcitabine/Nedaplatin (GN), and five studies did not mention the regimen The overall survival in the NAC + RC only group was significantly better than the RC only group (HR 0.82 [0.71-0.95],p = 0.009). Conclusion NAC + RC is recommended to improve overall survival in MIBC patients. A further study assessing side effects and quality of life regarding NAC + RC is needed to establish a strong recommendation regarding this therapy.