Clinical evaluation of chemosensitivity testing for patients with colorectal cancer using MTT assay

Abstract

PURPOSE: Colorectal cancer is one of the tumors most refractory to treatment by chemotherapy. The chemosensitivity test should be performed to individualize the chemotherapy for patients with colorectal cancer, which is less sensitive for anticancer drugs. The present study was designed to determine the chemosensitivity in fresh human colorectal cancer, using highly purified tumor cells, and the correlation of this sensitivity with clinical response. METHODS: We determined the chemosensitivity for cisplatin, mitomycin C, adriamycin, and 5-fluorouracil in vitro in 93 fresh human colorectal cancers using the MTT assay and performed chemotherapy according to results of the MTT assay. RESULTS: Inhibition rate of tumor cells for cisplatin was higher than those for other drugs. Fifteen patients who have evaluable lesions received chemotherapy according to results of the MTT assay. Clinical responses were obtained in 5 of 15 patients, and the inhibition rate for cisplatin was higher in responders than in nonresponders. CONCLUSIONS: It is suggested that the chemotherapy according to results of the MTT assay is effective in patients with colorectal cancer.