Gemcitabine-UFTE Chemotherapy in Refractory Colorectal Cancer

Although there have been remarkable advances in the treatment of metastatic or recurrent colorectal cancer (MRCRC), long term survival cannot be expected in most patients with MRCRC because of inevitably developing resistance to chemotherapeutic drugs except some MRCRC patients who can undergo complete resection (metastasectomy). Until now, approved cytotoxic drugs for treatment of MCRC are only 3 categories (fluoropyrimidine, oxaliplatin and irinotecan). Recently, molecularly targeted drugs are approved for MRCRC patients, and bevacizumab and cetuximab (for K-ras wild type tumors) are available. When cytotoxic and targeted drugs are appropriately combined, about 24 months of overall survival (OS) can be expected in patients with MRCRC. However, when these drugs are all used or patients cannot afford to receive expensive targeted drugs because of economical problems, there is no option for chemotherapy and best supportive care is the only option, although some patients still have good performance status and medical conditions. Therefore, there are unmet needs for additional salvage chemotherapy regimens for patients with oxaliplatin, irinotecan and fluoropyrimidine-refractory MRCRC. In some previous studies, gemcitabine-based chemotherapy showed some antitumor activities in MRCRC patients. Especially, when combined with fluoropyrimidine, gemcitabine has been shown to exert synergic effects on antitumor activities. On these backgrounds, this phase 2 clinical study was designed. In this study, efficacy and safety of gemcitabine plus UFTE chemotherapy will be evaluated in MRCRC patients.