UGT1A1*28, toxicity and outcome in advanced colorectal cancer: Results from Trial N9741

3520 Background: This report examines UGT1A1*28, toxicity, and outcome in trial NCCTG N9741 patients (pts) receiving combination chemotherapy for advanced colorectal cancer. Methods: Blood samples were collected from 520 pts randomized between 2/18/00 and 7/18/02. Pts were treated with irinotecan/5-fluorouracil (5FU)/leucovorin (LV) (IFL, n=114), oxaliplatin/5FU/LV (FOLFOX, n=299), irinotecan/oxaliplatin (IROX, n=107). 19% of IFL pts received full-dose (125 mg/m2) irinotecan; the rest received a reduced dose (100 mg/m2). Toxicity was evaluated every cycle. Correlation of dichotomous outcomes and genotype status used Fisher’s exact tests. Univariate logistic regression was used to test the association between continuous variables and binary outcomes, including a test of trend, and multivariate logistic regression to adjust for known risk factors: performance status, age, gender. Time to progression (TTP) and overall survival (OS) were tested for association with UGT1A1 using the log-rank test. Statistical ...