Sequential Treatment with Irinotecan and Doxifluridine: Optimal Dosing Schedule in Murine Models and in a Phase I Study for Metastatic Colorectal Cancer

Comparison of intraperitoneal with intravenous administration of taxol in experimental peritoneal carcinomatosis

BACKGROUND

Recurrent tumor growth of colorectal carcinoma at the peritoneal site remains an unsolved problem. The aim of this study was to investigate whether the substance taxol (paclitaxel) can alter intraperitoneal tumor spread using different modes of drug application.

METHODS

Intraperitoneal tumor growth was induced using a tumor cell transfer model (10(6) cells) in rats divided into 3 groups: (1) taxol was applied directly into the abdominal cavity, intraperitoneally or intravenously, immediately following intraperitoneal tumor cell transfer; (2) early postoperative intraperitoneal and intravenous chemotherapy was administered on days 5, 10 and 15 after surgical intervention using an intraperitoneal or intravenous port-a-cath; (3) control group. Thirty days after tumor cell transfer, rats were sacrificed, and tumor weight, number of nodes (at greater omentum and peritoneum) and ascites volume were determined.

RESULTS

Taxol generated a significant inhibitory effect on peritoneal tumor growth. Direct intraoperative intraperitoneal application of taxol induced a more pronounced effect compared with early postoperative intraperitoneal application of the antineoplastic drug. Both application modes were superior to the intravenous route (no significant effect).

CONCLUSION

Taxol appears to be a potential chemotherapeutic drug providing a significant effect in the therapeutic management of peritoneal carcinomatosis under experimental conditions. Combination of taxol with cytostatic agents and new drugs generating different effector mechanisms may help to further diminish or even to prevent intraperitoneal tumor growth.

A phase II study of irinotecan in combination with doxifluridine, an intermediate form of capecitabine, in patients with metastatic colorectal cancer

The purpose of this study was to examine the efficacy of a combination treatment of sequential irinotecan and doxifluridine, an intermediate of capecitabine, evaluated by the response rate and safety in patients with metastatic colorectal cancer. In all, 60 metastatic colorectal cancer patients with measurable disease were enrolled. The schedule of the treatment consisted of a 90 min intravenous (IV) infusion of irinotecan 150 mg/m2 for on days 1 and 15, and 600-1,000 mg/body of oral doxifluridine on days 3-14 and 17-28. Cycles were repeated every 35 days. A median of three cycles of the combination therapy (range 1-14 cycles) was administered. A total of 57 patients (95%) completed at least two cycles of the therapy without any dose reductions. There was one complete response and 23 partial responses with an overall response rate of 40% [95% confidence interval (CI): 28-53%]. A total of 19 patients had stable disease, 43(72%) achieved disease control. The median time to progression was 5.9 months and the median overall survival was 20.5 months. Ten (17%) and 17 (28%) patients developed Grade 3-4 leukopenia and neutropenia, respectively. Grade 3-4 fatigue was observed in 7(12%) patients, nausea in five (8%), vomiting in four (7%), and diarrhea,in three (5%) patients. No treatment-related deaths were noted during the study. From these results, the combination of sequential irinotecan and doxifluridine is considered to be an effective, easy-to-administer regimen with acceptable tolerability.