623 Background: Fluoropyrimidine-based combination chemotherapy, in combination with either oxaliplatin or irinotecan, have demonstrated efficacy and tolerability against advanced colorectal cancer (ACC). Methods: Between Jan 2006 and Dec 2007, 478 ACC patients were treated with combination chemotherapy in first-line setting: 5-fluorouracil, folinic acid plus oxaliplatin (FOLFOX, n=172), 5-fluorouracil, folinic acid plus irinotecan (FOLFIRI, n=95), capecitabine plus oxaliplatin (XELOX, n=155), and capecitabine plus irinotecan (XELIRI, n=56). FOLFOX and FOLFIRI were repeated every 2 weeks, whereas XELOX and XELIRI were repeated every 3 weeks until disease progression or unacceptable toxicity occurred or until a patient chose to discontinue treatment. Results: The median age was 58 years (range, 19-84 years) and the median chemotherapy duration for FOLFOX, FOLFIRI, XELOX and XELIRI were 4.9, 4.5, 5.7 and 5.4 months, respectively. Combination chemotherapy regimens were generally well tolerated. The estimated median PFS for all patients was 6.8 months (95% confidence interval, 6.3-7.3 months). No statistically significant difference in PFS was found each regimen used as first-line chemotherapy. Sixty-percent (n=290) of patients received second or further lines of therapy after failure. Conclusions: Fluoropyrimidine-based combination chemotherapy regimens appear to be equally active and tolerable as first-line therapy for ACC. No significant financial relationships to disclose.