A Phase II Study of Perioperative Capecitabine plus Oxaliplatin Therapy for Clinical SS/SE N1‐3 M0 Gastric Cancer (OGSG 1601)

Lessons Learned Perioperative capecitabine and oxaliplatin (CapeOx) therapy showed favorable efficacy with sufficient pathological response. Small sample size limited the statistical power of this result. Perioperative CapeOx therapy showed good feasibility. Further studies with larger sample size are required to validate this novel approach.Background D2 gastrectomy followed by adjuvant S‐1 is the standard therapy for patients (pts) with stage III gastric cancer (GC) in Japan; however, the outcome is not satisfactory. We examined the efficacy of perioperative capecitabine and oxaliplatin (CapeOx) in pts with GC. Methods The eligibility criteria included confirmed clinical T3(SS)/T4a(SE) N1‐3 M0 GC according to the Japanese Classification (JCGC; 3rd English Edition). Three cycles of neoadjuvant CapeOx (NAC; capecitabine, 2,000 mg/m 2 for 14 days; oxaliplatin, 130 mg/m 2 on day 1, every 3 weeks) were administered, followed by five cycles of adjuvant CapeOx (AC) after D2 gastrectomy. The primary endpoint was the pathological response rate (pRR) according to the JCGC (≥grade 1b). Results Thirty‐seven pts were enrolled on CapeOx. An R0 resection rate of 78.4% ( n = 29) and a pRR of 54.1% ( n = 20, p = .058; 90% confidence interval [CI], 39.4–68.2) were demonstrated. Among 27 pts who initiated AC, 21 (63.6%) completed the treatment. Grade 3–4 toxicities during NAC included neutropenia (8%), thrombocytopenia (8%), and anorexia (8%) and during AC included neutropenia (37%), diarrhea (4%), and anorexia (4%). Conclusion Perioperative CapeOx showed good feasibility and favorable efficacy with sufficient pathological response, although statistical significance at .058 did not reach the commonly accepted cutoff of .05. The data obtained using this novel approach warrant further investigations.