[The current status of postoperative adjuvant chemotherapy for colorectal cancer]

To evaluate the significance of postoperative adjuvant chemotherapy, randomized controlled trials of adjuvant chemotherapy after curative resection for colorectal cancer were reviewed. Several multiple-drug systemic chemotherapy (MOF, MMC/FT p.o., MMC/5-FU p.o., MMC/ UFT po) were useful as adjuvant treatment to improve survival or disease-free survival for patients with colorectal cancer. And worldwide meta-analysis found that continuous intraportal 5-FU was suggested to improve survival. Recently, combination chemotherapy trials utilizing 5-FU and levamisole, or 5-FU and leucovorin, demonstrated significant a survival advantage in the patients with high risk colon cancer, and these are widely used as adjuvant treatment for patients with Dukes C resected colon cancer. From results of many Japanese trials, although the effectiveness of adjuvant treatment for colorectal cancer still remain controversial, postoperative adjuvant chemotherapy is thought to improve the disease-free survival of patients after resection of rectal cancer or Dukes C colon cancer.