Sequential methotrexate and 5-fluorouracil: improved response rate in metastatic colorectal cancer.

Abstract
The efficacy of chemotherapy with sequential methotrexate (MTX) and 5-fluorouracil (5-FU) in metastatic colorectal cancer was studied in a multicenter phase II trial using a 7-h time interval. Patients (42) were evaluable for response and 16 achieved objective tumor regression (> 50%). Median survival of all patients was 12.5 mo. MTX and 5-FU are synergistic in human colorectal cancer if given sequentially with a 7-h time interval. This is supported by a review of the literature that reveals a significantly higher response rate in patients treated with a 4 h or more MTX/5-FU interval as compared to a 1 h interval.