- The urgent need for new effective therapy with better safety profile for metastatic colorectal cancer patients and promising results observed so far in trials with S-1 combined with oxaliplatin in gastrointestinal cancer including colorectal cancer strongly warrants the comparison of S-1 combined with oxaliplatin to capecitabine combination with oxaliplatin acknowledged as a standard regimen in a first-line treatment for advanced colorectal cancer patients.