Adjuvant treatment of colorectal adenocarcinoma

Colorectal adenocarcinoma is diagnosed in 150,000 Americans yearly, and more than 50,000 die of this disease each year. Recently, as a result of well-controlled, randomized, cooperative group trials, it has been demonstrated that adjuvant therapy of node-positive colon cancer (stage III) and node-positive or negative rectal cancer (stage II or stage III) can reduce recurrence and mortality and significantly improve overall survival. It is now the standard of care to provide adjuvant chemotherapy with 5-fluorouracil and levamisole for patients with node-positive colon cancer and provide adjuvant chemoradiotherapy with both 5-fluorouracil and high-dose radiotherapy for patients with stage II or stage III rectal cancer. It is estimated that these interventions, which are readily tolerated, will reduce the incidence of recurrence by more than 30% in both patient groups at a reasonable economic and health cost. Although the ideal method of therapy for this type of disease is not yet firmly established, it appears that adjuvant therapy for node-negative stage III colon cancer may be effective as well. Recently completed and ongoing cooperative group trials are investigating different combinations of chemotherapy and radiotherapy, including 5-fluorouracil with the biomodulator leucovorin or continuous-infusion 5-fluorouracil with radiotherapy, and comparing different durations of therapy. Other trials are investigating combined modality therapy for the neoadjuvant treatment of locally advanced rectal cancer. New findings in the genetics of colon cancer are being studied as prognostic information or markers to determine whether there are subsets of patients who might benefit from more or less therapy. Randomized placebo-controlled trials have been initiated to study the use of aspirin as a means of colon cancer prevention in high-risk populations. Taken together, the recent advances in our treatment and understanding of colorectal adenocarcinoma have resulted in a major--albeit silent--revolution in therapy and give firm promise for further progress.