[S-1 for gastric cancer-S-1 monotherapy and its progress].

Two pivotal phase II studies of S-1 in advanced gastric cancer showed response rates of 44% and 49%, and the overall survival time was 207 and 250 days, respectively. The response rate of S-1 exceeded the response rates of other approved drugs, and was comparable to that of combination chemotherapies such as 5-fluorouracil (5-FU) plus cisplatin (CDDP). These data suggested that S-1 could be used as a first-line drug for gastric cancer with a great advantage in quality of life (QOL), because it is an oral drug and can be used at an outpatient clinic.