Postoperative chemotherapy for colorectal cancer by combining 5-fluorouracil infusion and 1-hexylcarbamoyl-5-fluorouracil administration after curative resection.

BACKGROUND

Colorectal cancer is one of the major malignant diseases and, recently, its incidence appears to be increasing. Surgical resectability is an important prognostic determinant; however, recurrent tumors are commonly noted, even after apparently curative surgery. Because such metastatic disease cannot be cured, better adjuvant therapies are urgently called for.

METHODS

We studied the effect of postoperative chemotherapy using 5-fluorouracil (5-FU) infusions and 1-hexylcarbamoyl-5-fluorouracil (HCFU) oral administration for curatively resected Stage II to IV colorectal cancer. This study was prospectively randomized and controlled and 251 (93.3%) of 269 patients were determined to be candidates for statistical assessment. The inductive regimen for Group A included a total of 6 5-FU intravenous injections, 10 mg/kg, on postoperative days 0, 1, 2, 7, 8, and 9. For maintenance therapy, Group A also received oral HCFU, 300 mg daily for 52 weeks beginning 2 weeks after surgery. The regimen for Group B included only 5-FU injections of Group A.

RESULTS

There were no differences in the prognostic factors or doses of 5-FU between Groups A and B. In addition, no difference was observed in the toxicity rate between the two groups. Group A, with 5-FU infusions plus oral HCFU administration, produced a reduction in the recurrence rate and a prolongation of the survival time for patients with rectal cancer. In a retrospective analysis, this protocol was also effective for patients with Stage III to IV, wall invasion-positive, and lymph node metastasis-positive colorectal cancers.

CONCLUSIONS

This study suggests that the combination of 5-FU infusions and the continuous oral administration of HCFU is a reasonable therapeutic approach for patients with surgically resected colorectal cancer and a high risk of recurrence.