Adjuvant therapy for colorectal carcinoma

Adjuvant therapy for colorectal carcinoma has been developed over the last two decades. We have reviewed the history of adjuvant chemotherapy for colorectal carcinoma in the United States, Europe and Japan with regard to the rationale of the chemotherapy regimen and the survival benefit for the establishment of a standard regimen. Treatment with 5-fluorouracil (5-FU) and leucovorin (LV) for postoperative adjuvant chemotherapy had an overall survival benefit, compared with surgery alone, in randomized controlled trials in the United States and Europe for Dukes' C colon carcinoma. In contrast, the survival benefit of adjuvant chemotherapy for Dukes' B colon carcinoma and for rectal carcinoma has not yet been established. In Japan, randomized controlled trials have examined combination treatment with mitomycin (MMC) and oral fluoropyrimidines for colorectal carcinoma compared with surgery alone. A meta-analysis indicated that combination treatment with MMC and oral fluoropyrimidines had a survival benefit for colorectal carcinoma. The survival benefit of combination treatment with irinotecan (CPT-11) + 5-FU + LV or uracil + tegaful (UFT) + LV (Orzel) for adjuvant chemotherapy are currently being compared with 5-FU + LV. Meta-analysis revealed a survival benefit at 2-years in the prevention of liver metastasis following intraportal or intraarterial infusion of 5-FU. The survival benefit of preoperative radiotherapy was superior to postoperative radiotherapy for advanced rectal carcinoma in association with the prevention of local recurrence. Clinical trial data suggest that the current standard regimen of adjuvant chemotherapy is a combination of 5-FU and LV for Dukes' C colon carcinoma and that radiotherapy for local control of rectal carcinoma has a survival benefit.