A meta-analysis of efficacy and safety of S-1 monotherapy or combination therapy as first-line treatment in metastatic colorectal cancer.

Purpose: To compare the efficacy and safety profile of S-1-based versus non-S-1-based chemotherapy as first-line treatment in mCRC.

Methods: Relevant randomized controlled trials (RCTs) were obtained from PubMed, Embase, and Ovid databases and the Cochrane library from database set up in May 2018. The RCTs of S-1-based monotherapy or combination therapy as first-line treatment were selected. The impact of S-1-based chemotherapy on progression-free survival (PFS) and overall survival (OS) was assessed by pooling data via RevMan 5.3.

Results: Meta-analysis of 10 RCTs showed that S-1-based chemotherapy significantly improved PFS (HR 0.90, 95% CI 0.84-0.97, P = 0.006). In subgroup analysis, there was a statistically significant increase in PFS when S-1-based chemotherapy was compared with 5-FU-based (HR 0.92, 95% CI 0.84-1.00, P = 0.04) or capecitabine-based chemotherapy (HR 0.85, 95% CI 0.73-0.99, P = 0.04). The meta-analysis of OS (HR 0.95, 95% CI 0.86-1.05, P = 0.36), overall response rate (ORR) (HR 0.99, 95% CI 0.84-1.17, P = 0.90), and disease control rate (DCR) (HR 1.61, 95% CI 0.87-3.00, P = 0.13) showed no statistical significance between S-1-based and non-S-1-based chemotherapy. The statistically significant differences in the meta-analysis indicated less incidence of graded 3-4 leucopenia (OR = 0.30, 95% CI 0.13-0.71, P = 0.006) and hand-foot syndrome (HFS) (OR = 0.24, 95% CI 0.10-0.58, P = 0.001) in the S-1-based chemotherapy, and there was no statistically significant difference for other adverse events.

Conclusions: S-1-based chemotherapy in mono or combined therapy was an attractive alternative to standard first-line regimen for patients of mCRC.