High- versus low-dose leucovorin in the modified FOLFOX6 regimen for first-line treatment of metastatic colorectal cancer.

Background In response to the national leucovorin shortage in 2008, our institution adjusted the modified FOLFOX6 (leucovorin, fluorouracil, and oxaliplatin) protocol to utilize a lower dose of leucovorin (20 mg/m). This adjustment was based on prospective studies suggesting that lower doses of leucovorin may be equally effective in other fluorouracil containing regimens. This retrospective study evaluates outcomes in metastatic colorectal cancer (mCRC) patients treated with low- (20 mg/m) vs.