[The efficacy of S-1 monotherapy as a 2nd/3rd-line therapy for unresectable recurrent colon cancer: Kanagawa conference of clinical oncology (KCCO)].

Objective: The efficacy of S-1 as part of a 2nd/3rd-line therapy in cases of advanced recurrent colon cancer was studied.
Subjects and Methods: The efficacy of treatment with S-1 (initial dosage: 80 mg/m(2)) was studied in 19 patients with advanced recurrent colon cancer in whom PD was observed after pretreatment with 5-FU-based combination chemotherapy had been performed during the period from December 2003 to April 2006. Patients who underwent a course that exceeded 1 month after the pretreatment and who met the criteria for the appropriate use of S-1 were selected as subjects.
Results: The median age was 65 years (45 to 75 years old) with 10, 6, and 3 patients having a PS score of 0, 1, and 2, respectively, and the details of the duration of the pretreatment was that 12 and 7 patients respectively received 2nd-and 3rd-line therapy. The median duration of the treatment with S-1 was 141 days, and the number of subjects with PR, SD, and PD who underwent S-1 treatment was 2, 7, and 6, respectively, with a response rate of 13. 3% and a disease control rate of 60. 0%. The progression free survival time and the overall median survival time were 5. 4 months and 13. 9 months, respectively. Regarding the effectiveness according to treatment line, particularly in the subjects who were administered S-1 as part of the 2nd-line therapy, good results were observed, thus showing a response rate of 20% and an overall median survival time of 13. 9 months, which exceeded 1 year. The incidence of adverse events was 58%(11 and 19), and the major side effects were neutropenia in 31. 6% (6 and 19) and leukopenia in 21. 1% (4 and 19) of the patients, which are both mild and showed a grade of 2 or lower.
Conclusion: The use of S-1 as part of a 2nd/3rd-line therapy in cases of advanced recurrent colon cancer may contribute to good prognoses.