Synergistic antitumoral activity of combined UFT, folinic acid and oxaliplatin against human colorectal HT29 cell xenografts in athymic nude mice

This study was designed to asses the inhibition of tumor growth by oxalipla tin combined with UFT and folinic acid (FA). Growth inhibition was studied in nude mice transplanted with human colorectal HT29 tumor cell xenografts and treated for 28 days with oral UFT (20 mg/kg/day) and FA (4 mg/kg/day), i.p. oxaliplatin (10 mg/kg on day 1) or a combination of oxaliplatin, UFT a nd FA, or else not treated (controls). Tumor surface area and weight were r ecorded twice a week, and mice were sacrificed at day 28. Two separate expe riments were performed for each group of 25 mice. At day 28, mean tumor wei ghts (9) were 2.89+/-0.22 (controls), 2.03+/-0.14 (oxaliplatin), 2.02+/-0.2 1 (UFT/FA) and 1.23+/-0.17 (oxaliplatin+UFT/FA). For the three treatment gr oups, tumor weight decreases were 30.1% (p<0.05), 29.9% (p<0.05) and 57.5% (p<0.001), respectively. Combined treatment (UFT/FA+oxaliplatin) reduced tu mor weight by 39% compared to oxaliplatin alone (p<0.05) or UFT/FA (p<0.05) . These results demonstrate the synergistic effect of the combination of ox aliplatin, UFT and FA in this HT29 cell xenograft model, and warrant furthe r investigations in patients with metastatic colorectal cancer. [(C) 2000 L ippincott Williams & Wilkins].