Published in:
01-09-2015 | Original Article
S-1 and irinotecan with or without bevacizumab versus 5-fluorouracil and leucovorin plus oxaliplatin with or without bevacizumab in metastatic colorectal cancer: a pooled analysis of four phase II studies
Published in: Cancer Chemotherapy and Pharmacology | Issue 3/2015
Login to get accessAbstract
Purpose
S-1, a novel oral prodrug of 5-fluorouracil (5-FU), and irinotecan with or without bevacizumab is known to be effective in metastatic colorectal cancer (mCRC). However, it is not clear whether S-1 and irinotecan confers benefits compared to 5-FU and leucovorin plus oxaliplatin (FOLFOX) in patients with mCRC. Our aim was to compare the efficacy and safety of these regimens.
Methods
We analyzed 187 patients with previously untreated mCRC who were enrolled in four phase II studies: SIR (S-1 and irinotecan, n = 40), SIRB (S-1 and irinotecan with bevacizumab, n = 51), FOLFOX (5-FU and leucovorin plus oxaliplatin, n = 46), and STOX (stop-and-go strategy of modified FOLFOX-6 with bevacizumab, n = 50). We evaluated efficacy and safety between SIR/SIRB and FOLFOX/STOX.
Results
Baseline characteristics were similar in the two groups composed of SIR/SIRB (n = 91) and FOLFOX/STOX (n = 96). The overall response rates were not significantly different between the two groups (65 % in SIR/SIRB vs. 52 % in FOLFOX/STOX, p = 0.125). The median progression-free survival was 10.9 months in SIR/SIRB versus 12.1 months in FOLFOX/STOX (p = 0.59). The median overall survival was 27.3 months in SIR/SIRB versus 26.8 months in FOLFOX/STOX (p = 0.97). Gastrointestinal adverse events were the most common toxicities in SIR/SIRB, while neutropenia and sensory neuropathy were the most common toxicities in FOLFOX/STOX.
Conclusions
S-1 and irinotecan with or without bevacizumab was well tolerated and showed similar response rates and survival compared to the FOLFOX regimen. This combination should be considered as an experimental first-line treatment for mCRC.