Comparision of Weekly and Bi-weekly Schedules of Irinotecan, Leucovorin, and Infusional Fluorouracil in Patients with Stage IV Colorectal Caner

Aims. Irinotecan (CPT-11) is a potent anticancer drug for colorectal cancer. It has been proven to have antitumor activity against metastatic colorectal cancer when used alone as first-line treatment or as second-line treatment. In this study, we investigated the results of treatment with different regimens using irinotecan. Methods. From July 1998 to October 2000, 61 patients with stage IV colorectal cancer were enrolled. Thirty-four patients received a weekly regimen and 27 patients received a bi-weekly regimen. Response to the drug was categorized into four grades including complete response, partial response, stable disease, progression. The severity of adverse effects was evaluated using the National Cancer Institute Toxicity Criteria. Results. Response rates were 11.8% and 7.4% in the weekly and biweekly groups, respectively. The stable disease accounted for 70.6% in the weekly and 59.3% in the bi-weekly groups. The median time to progression showed no difference (6.9 vs. 6 months, p = 0.80). Median overall survival time also showed no difference (9.5 vs. 10.9 months, p = 0.63). In addition, the overall 1-year survival rate was 41.7% and 2-year survival was 11.1%. There were six patients who experienced grade 3 or 4 neutropenia. Vomiting was the most common toxic side effect, followed by alopecia. Fewer patients with diarrhea were noted in both the weekly and bi-weekly groups. Conclusions. Irinotecan was used for stage IV colorectal cancer for which treatment with fluorouracil had failed, and it has acceptable safety. Patients mostly tolerated irinotecan treatment and achieved prolonged overall survival. Neutropenic complications were still a lethal problem, but the incidence decreased after we switched to a bi-weekly regimen.Alower incidence of grade III and IV diarrhea was noted. So we suggest that irinotecan is a safe and potent drug for treatment of patients with advanced colorectal cancer for which fluorouracil treatment had failed.