Oxaliplatin/5-FU without leucovorin chemotherapy in metastatic colorectal cancer

Fluorouracil (5-FU) and leucovorin combination therapy have shown synergistic or additive effect against advanced colorectal cancer, but the frequency of mucositis and diarrhea is increased. Most previous studies have used high dose leucovorin (300 approximately 500 mg/m(2)). However, some studies of oxaliplatin and 5-FU with low-dose or high-dose leucovorin in Korea have shown similar response rates. Therefore, we studied the necessity of leucovorin and evaluated the objective tumor response rates and toxicities of a regimen of oxaliplatin and 5-FU without leucovorin every 2 weeks in metastatic colorectal cancer patients.

Twenty-four patients with metastatic colorectal cancer were enrolled between January 2002 and March 2003. Patients received 85 mg/m(2) of oxaliplatin on day 1, a bolus 5-FU 400 mg/m(2) on day 1 and a continuous 5-FU infusion at 600 mg/m(2)/ 22 hours days 1 and 2, every 2 weeks.

Of the 24 patients treated, 17 patients received previous 5FU with leucovorin and/or other chemotherapy. Three patients could not be evaluated. Five partial responses were observed with overall response rate of 21% (n=24). Of the previous chemotherapy group (n=17), 4 partial responses were observed with response rate of 24%. Median overall survival was 18 months (range 4 approximately 32 months) and median progression free survival was 4 months (range 2 approximately 6 months). This regimen was well tolerated and only 1 grade 3 anemia was observed.

Oxaliplatin/5-FU combination therapy without leucovorin achieved a relatively high response rate even in patients resistant to the previous 5-FU chemotherapy, and toxicity was minimal.