Regional intra-arterial mitomycin C infusion in previously treated patients with metastatic colorectal cancer and concomitant measurement of serum drug level.

Fifty-seven patients with unresectable metastatic colorectal cancer, after failing all conventional chemotherapy, were treated with mitomycin C (MMC) regional intra-arterial infusion. The regional artery (eg, hypogastric, hepatic, etc) was approached percutaneously via the femoral artery and MMC at a dose of 20 mg/m2 in 100 ml of 5% dextrose in water was infused for a 1-hour period; treatment was repeated every 6-8 weeks. Of 51 evaluable patients, five had objective response (three with pelvic tumor, one with liver and lung tumors, and one with liver tumors), 28 had stabilization of tumor, and 18 had no response. Median survival times for the responders, stabilized patients, and nonresponders were 46+, 39, and 22 weeks, respectively, with an overall survival of 32 weeks. The major side effect was necrotizing cellulitis occurring in the buttock following the pelvic infusion. Myelosuppression was manageable and other toxic effects were mild. Using the high-performance liquid chromatography method (total of 25 measurements), the average MMC levels in the peripheral circulation were 205, 62.4, and 16.0 ng/ml, respectively, immediately after injection and 1 and 2 hours following intra-arterial infusion. By 4 hours, no MMC could be detected in the peripheral circulation.