[Surgery and multidisciplinary treatment for colorectal cancer]

Evaluation of surgery and multidisciplinary treatment for colorectal cancer was performed based on the review of the results of clinical trials. Although most improvement in prognosis for colorectal cancer patients was obtained by the development of surgical techniques until the mid-70's, further extended surgery could not have demonstrated the obvious improvement in survival after the 80's. In this regard, various multidisciplinary treatments were evaluated by a meta-analysis of clinical trials. Among those modalities, preoperative irradiation for rectal cancer, postoperative adjuvant chemotherapy for resected colorectal cancer and biochemical modulation of 5-fluorouracil by methotrexate or leucovorin for advanced colorectal cancers proved to be significantly effective for improvement of prognosis. Clinical trials of immunochemotherapy using either levamisole or PSK for resected colorectal cancers, a trial of hepatic artery infusion for liver metastasis, and a trial of an adjuvant monoclonal antibody treatment, were also reported to demonstrate significant effects. For further progress in multidisciplinary treatment for colorectal cancers, standardization of the appropriate surgical technique for each stage of the disease is much anticipated.