Methotrexate, vinblastine, adriamycin, and cisplatin (MVAC) versus gemcitabine, and cisplatin (GC) as neoadjuvant chemotherapy in muscle-invasive bladder cancer, a systematic review and meta-analysis

e16522 Background: Cisplatin-based neoadjuvant chemotherapy is the standard of care for muscle invasive bladder cancer (MIBC) in cisplatin-eligible patients. This systematic review and meta-analysis provide an updated efficacy and safety comparison between the two most commonly used cisplatin-based regimens; dose-dense (dd) or conventional MVAC versus GC. Methods: We searched different databases for studies comparing MVAC versus GC in the neoadjuvant setting. Outcomes of interest included overall survival, downstaging to pT≤1, pathologic complete response (pCR), recurrence, and toxicity. Meta-analysis was conducted using the random-effects model. Results: We identified 24 studies from inception to March 2020; among them 17 were peer reviewed and 7 were only reported as abstracts in national or international meetings, including a phase 3, randomized-controlled clinical trial. Among peer-reviewed published studies, efficacy outcomes such as OS, downstaging and pCR were comparable between conventional MVAC and GC for MIBC. If including non-peer-reviewed studies, dd-MVAC was associated with favorable efficacy compared to GC in terms of downstaging (OR 1.45; 95% CI 1.15–1.82), and OS at longest follow-up (OR 0.63; 95% CI 0.44–0.81). However, GC was associated with a better safety profile in terms of febrile neutropenia (OR 0.32; 95% CI 0.13–0.80), anemia (OR 0.32; 95% CI 0.18–0.54), nausea and vomiting (OR 0.27; 95% CI 0.12–0.65) compared to dd-MVAC. Compared to MVAC, patients receiving GC had an increased risk of developing grade 3–4 thrombocytopenia (OR 4.70; 95% CI 1.59–13.89) and a lower risk of nausea and vomiting (OR 0.05; 95% CI 0.01-0.31). Certainty in the estimates was very low for most outcomes. Conclusions: Among peer-reviewed published studies, efficacy and safety outcomes were comparable between conventional MVAC and GC for MIBC. However, If including non-peer-reviewed studies, this analysis showed higher efficacy with dd-MVAC. A phase III randomized trial comparing the two regimens is needed to guide clinical practice