Feasibility Study of Oxaliplatin with Oral S-1 or Capecitabine as First-line Therapy for Patients with Metastases from Colorectal Cancer

Background/Aim: The aim of this study was to determine the feasibility of S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (XELOX) as first-line therapy for patients with initially unresectable metastases from colorectal cancer. Patients and Methods: Fourteen patients with colorectal cancer who underwent elective colorectal resection between January 2009 and December 2010 at the Department of Surgery, Kashiwa Hospital, the Jikei University School of Medicine, with initially unresectable metastatic lesions were enrolled in this study. After curative resection for the primary colorectal cancer, they underwent adjuvant chemotherapy with SOX or XELOX, starting at one month after surgery. Results: Seven patients (50%) received SOX, and the others received XELOX as first-line therapy for initially unresectable metastases from colorectal cancer. Four (29%) patients had complete response for liver metastases over six months after chemotherapy, and liver metastases were subsequently judged to be completely resected by surgery. For the other ten patients, the median progression- free survival was 9.1 months and median overall survival was 24.1 months. There were no patients with grade 3 or 4 adverse reactions throughout the entire chemotherapy. Conclusion: Oxaliplatin with oral S-1 or capecitabine as first-line therapy for patients with initially unresectable metastases from colorectal cancer is safe and feasible. 5-Fluorouracil/folinic acid (5FU/FA) plus oxaliplatin (FOLFOX4 or FOLFOX6) has been the standard systemic regimen in the first-line treatment for patients with metastatic colorectal cancer (1-3). However, infusion of 5-FU with FA has the disadvantages of increased inconvenience, cost, and morbidity related to the use of a portable infusion pump and a central venous catheter. Oral fluoropyrimidine derivatives have been developed to circumvent the problems associated with continuous infusion of 5-FU. S-1 (Taiho Pharmaceuticals Co. Ltd., Tokyo, Japan) combines tegafur with two modulators of 5-FU metabolism and capecitabine (Xeloda; Hoffmann-La Roche, Basel, Switzerland) are effective derivatives used in Japan. This study was undertaken to determine the feasibility of S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (XELOX) as first-line therapy for patients with initially unresectable metastases from colorectal cancer.