[Effectiveness of postoperative adjuvant chemotherapy using S-1 plus CDDP for type 4 gastric cancer]

Our aim was to evaluate postoperative adjuvant chemotherapy using S-1 plus cisplatin(S-1/CDDP)for type 4 gastric cancer.We investigated 18 patients who had undergone curative operations for type 4 gastric cancer. They were classified into two groups of patients, one using S-1/CDDP(group A: 9)and one using S-1 alone(group B: 9), after surgery between 2000 and 2010. Median survival time(MST)and survival rates were reported retrospectively. Patients as- signed to group A were treated with the following regimen: S-1, 80-120mg/day(body surface area 1. 25m2: 80mg/day, 1. 25-1. 5m2: 100mg/day, 1. 5m2: 120mg), was administered for 21 consecutive days followed by a 14-day rest period, and CDDP, 60mg/m2, was administered on day 8 for 5 courses. After this course, S-1 80mg/m2 was given for 18 months. S- 1(80-120mg/day, body surface area 1. 25m2: 80mg/day, 1. 25-1. 5m2: 100mg/day, 1. 5m2: 120mg)was administered for 28 days followed by 14-day rest as one course.MST differed significantly between group A and group B (MST; group A: 1, 603 vs group B: 955 days). The overall survival rate at 5 years was 64. 8% in group A and 13% in group B, and the overall survival rate in group A was statistically better than that in group B(p=0. 02).Postoperative adjuvant chemotherapy using S-1/CDDP for resected type 4 gastric cancer contributes to prolonged life, compared with using S-1 in overall survival.