Does capecitabine plus cisplatin (XP) give advanced or recurrent gastric cancer (AGC) patients higher early tumor shrinkage (ETS) rate than S1 plus cisplatin (SP) with safety?

Abstract

172 Background: Capecitabine plus cisplatin (XP) is defined as the platform regimen in many global trials (ex: ToGA, AVAGAST) for AGC in first-line setting. But in the Japanese Gastric Cancer Treatment Guideline (4th edition), S-1 plus cisplatin (SP) is mentioned the standard (recommendation 1), XP is considered as recommendation 2. Few reports were existed about the comparison between XP and SP. So we retrospectively compared the efficacy and toxicity of XP and SP for patients with AGC in our hospital. Methods: The selection criteria were pathologically proven AGC (HER2 negative or unknown); no previous chemotherapy; performance status 0-2; able to oral intake; and adequate organ functions. The patients in XP group, capecitabine 1,000mg/m2 was given orally twice daily for 14days followed by a 7-day rest; cisplatin 80mg/m2 on day1 was given by intravenous infusion. In SP group, S1 40mg/m2 was given orally twice daily for 21 days followed by a 14-day rest and cisplatin 60mg/m2 intravenous infusion on day8. Results: The analysis covered 115 patients over the period from May 2008 to June 2014. The median age was 64 years (range 22-81); 76 males and 39 females; PS 0/1/2 score 85/29/1; 31 patients were treated XP and 84 patients were treated SP. Progression-free survival and overall survival were 6.6 and 16.4 months with XP and 6.1 and 13.3 months with SP (no significant difference). The response rates were XP/SP 61%/50%. The ETS (over 20% tumor shrinkage in 6-8weeks) rate were 83% in XP and 61% in SP (p=0.09). The rate of grade 3-4 toxicity in XP/SP were; neutropenia 23%/15%, anemia 16%/20%, nausea 0%/3%, anorexia 3%/ 8%, fatigue 0%/ 4%, hyponatremia 3%/ 0%. There was no treatment death in both groups. Conclusions: It is suggested that XP give AGC patients high ETS rate with safety.