OBJECTIVETo evaluate the safety and preliminary efficacy of modified FOLFOXIRI (combination of reducing dosage irinotecan, oxaliplatin and fluorouracil) in first-line treatment for patients with metastatic colorectal cancer.

METHODA total of 53 patients with advanced colorectal cancer receiving modified FOLFOXIRI regimen were recruited continuously from January 2010 to January 2014. Safety profile was recorded based on NCI Common Terminology Criteria for Adverse Events version 3.0 (NCI-CTCAE v3.0). Objective response was evaluated by Response Evaluation Criteria in Solid Tumors version1.1 (RECIST 1.1) after administration of at least 4 cycles chemotherapy. Kras and Braf gene sequencing was tested by dideoxy chain-termination method. Relation between efficacy and two genes was examined.

RESULTSAmong 53 patients, no treatment-related mortality was presented. The rate of grade 3 to 4 adverse event was 32.1% (17/53), including neutropenia 13.2%(7/53), anemia 11.3% (6/53) and fatigue 9.4% (5/53). Overall response rate (ORR) and disease control rate (DCR) were respectively 65.9% (29/44) and 90.0% (40/44). Radical resection rate (R0) was 29.5% (13/44). Efficacy of mFOLFOXIRI regimen plus targeting therapy was assessed in 44 patients. mFOLFOXIRI regimen plus targeting therapy achieved an ORR of 72.7% (8/11), which was higher than the ORR 65.9% (21/33) of triplet regimen alone, but the difference was not statistically significant (P=0.198). Paraffin specimens of 48 colorectal cancer cases were tested. Twenty-one cases were Kras mutant (43.75%), 3 cases were Braf mutant (6.25%). There were no significant differences between two groups (P>0.05).

CONCLUSIONReducing dosage mFOLFOXIRI can be safely used in advanced colorectal cancer and can achieve promising results in terms of short term efficacy.