<qa>  What was the effect of 5-FU plus leucovorin on colon cancer?Based on the encouraging antitumor activity of 5-FU plus leucovorinLV in patients with metastatic colon carcinoma6,7, several investigators reported their results using this combination in the adjuvant setting. Results of an NSABP C-038 suggested that postoperative 5-FU plus leucovorin reduces the risk of colon cancer recurrence by 30 and the associated mortality by 32 compared with MOFsemustine, vincristine, and 5-FU. Recently, investigators from the IMPACT group9 analyzed the role of adjuvant 5-FU plus high dose leucovorin given 5 days every 28 days for a total of six courses versus no treatment in patients with stage II or III colon cancer. The treatment arm showed a significant reduction by 22 in mortality P0.029 and a 35 reduction in relapse rate P0.0001. Preliminary results from other studies have also suggested benefits of 5-FU plus leucovorin as adjuvant treatment of colon cancer10,11,12. Those studies had employed chemotherapy with 5-FU plus leucovorin, although there were differences in duration of treatment and drug dose among those trials, it is striking that all revealed a similar magnitude of benefit for adjuvant chemotherapy with 5-FU and leucovorin in node positive patients. At the present time, both 5-FU plus levamisole and 5-FU plus leucovorin can be considered acceptable adjuvant chemotherapy regimens for patients with node positive disease. 