Indications for and results of combined modality treatment of colorectal cancer

Combined modality chemoirradiation is commonly used as a component of treat ment in combination with maximum resection for both high-risk resectable an d locally advanced primary or recurrent rectal cancers. With surgically res ected but high-risk rectal cancers, postoperative chemoirradiation has been shown to improve both disease control (local and distant) and survival (di sease-free and overall) and was recommended as standard adjuvant treatment at the 1990 National Institute of Health (NIH) Consensus Conference on Adju vant treatment For patients with rectal and colon cancers. Subsequent inter group trials are bring conducted to help define optimal combinations of pos toperative chemoirradiation for resected high-risk rectal cancers and to te st sequencing issues of preoperative versus postoperative chemoirradiation. With locally unresectable primary or recurrent colorectal cancers, standard therapy with surgery, external beam irradiation (EBRT) and chemotherapy is often unsuccessful. When intraoperative electron irradiation (IOERT) is co mbined with standard treatment, local control, and survival appear to be im proved in separate analyses from the Mayo Clinic and the Massachusetts Gene ral Hospital (MGH), However routine use of systemic therapy is also needed as a component of treatment, in view of high rates of systemic failure.