EORTC Early Clinical Studies Group early phase II trial of S-1 in patients with advanced or metastatic colorectal cancer
Van den Brande, J × Schöffski, Patrick Schellens, J H M Roth, A D Duffaud, F Weigang-Köhler, K Reinke, F Wanders, J de Boer, R F Vermorken, J B Fumoleau, P #
British Journal of Cancer vol:88 issue:5 pages:648-653
Cancer of the colon and rectum is one of the most frequent malignancies both in the US and Europe. Standard palliative therapy is based on 5-fluorouracil/folinic acid combinations, with or without oxaliplatin or irinotecan, given intravenously. Oral medication has the advantage of greater patient convenience and acceptance and potential cost savings. S-1 is a new oral fluorinated pyrimidine derivative. In a nonrandomized phase II study, patients with advanced/metastatic colorectal cancer were treated with S-1 at 40 mg m-2 b.i.d. for 28 consecutive days, repeated every 5 weeks, but by amendment the dose was reduced to 35 mg m-2 during the study because of a higher than expected number of severe adverse drug reactions. In total 47 patients with colorectal cancer were included. In the 37 evaluable patients there were nine partial responses (24%), 17 stable diseases (46%) and 11 patients had progressive disease (30%). Diarrhoea occurred frequently and was often severe: in the 40 and 35 mg m-2 group, respectively, 38 and 35% of the patients experienced grade 3-4 diarrhoea. The other toxicities were limited and manageable. S-1 is active in advanced colorectal cancer, but in order to establish a safer dose the drug should be subject to further investigations.