P2-070 - Efficacy and Safety of S-1 Combined with Weekly Cisplatin for Metastatic Gastric Cancer

Abstract

ABSTRACT Background Based on the SPIRITS trial, S-1–cisplatin (SP) has been established as a first-line standard chemotherapy for metastatic gastric cancer in Japan. However, high-dose CDDP requires in-hospital treatment of hydration. S-1 combined with weekly cisplatin (weekly SP) can be administered in an outpatient setting by dividing CDDP into two doses. We studied efficacy and safety of weekly SP retrospectively. Method We conducted a retrospective review of the data of 40 patients (man/woman: 26/14) with metastatic gastric cancer who received weekly SP during March 2008 and June 2011. S-1 was administered orally 80–120 mg/day for 14 days and CDDP 30 mg/m2 was administered on days 1 and 8, repeated every 3 weeks. Toxicities were evaluated according to CTCAE v4.0 and tumor responses were assessed according to RECIST 1.1. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan–Meier method. Result The median age was 69 (45–83). Performance status (0/1/2) was 26/12/2. The unresctable/reccurent cancer was 33/8. The median number of treatment cycles was 7 (3–27); 14 are alive and 3 patients of them still receive weekly SP as a first-line therapy. Tumor responses were CR 1, PR 18, SD 15 and PD 6, and the response rate (RR) was 47.5%. The grade 3/4 toxicities were neutropenia (30%), anemia (12.5%), anorexia (5%), oral mucositis (5%), thrombocytopenia (2.5%), diarrhea (2.5%) and sensory neuropathy (2.5%). The median PFS time was 6.4 months, and the median survival time was 11.4 months. Conclusions Weekly SP for metastatic gastric cancer has less severe toxicity prolile and PFS / OS and RR are similar to SP. Weekly SP appears to be highly efficacious and safe and is a valid option for treatment in an outpatient setting.