Irinotecan plus fluorouracil/leucovorin (IFL) versus fluorouracil/leucovorin alone (FL) in stage III colon cancer (intergroup trial CALGB C89803).

3500 Background: Irinotecan prolongs survival in second line 5FU-refractory metastatic colorectal cancer (MCRC). First line irinotecan, weekly bolus 5FU, and leucovorin (IFL) was superior to daily x 5 bolus 5FU and leucovorin alone (FL) in a phase III trial in MCRC in terms of response rate, progression free survival and overall survival (OS). We conducted a phase III randomized study to evaluate whether IFL was also superior to weekly bolus FL after curative resection for stage III colon cancer. METHODS: Eligible patients had TxN1-2M0 disease, Zubrod 0-2, and no prior chemotherapy. Patients (pts) received either IFL (irinotecan 125mg/m2 over 90 minutes followed by leucovorin 20 mg/m2 IV bolus and then 5FU 500mg/m2 IV bolus, given 4 weeks on, 2 weeks off, x 5 cycles (30 weeks total)) or the Roswell Park schedule of FL (leucovorin 500mg/m2 IV over 2 hours plus 5FU 500 mg/m2 at 1 hour after start of leucovorin, given 6 weeks on, two weeks off, x 4 cycles (32 weeks total)). Pts were stratified for N1 vs. N2 disease, high vs. low grade histology, and preoperative CEA of < 5 ng/ml, ≥ 5ng/ml, or unknown. RESULTS: 1264 pts were randomized between April, 1999 and April, 2001. Median follow up is 2.6 years, and 67% of total expected deaths and 85% of total expected failures have occurred. Median OS and failure-free survival (FFS) have not yet been reached. IFL shows no improvement over FL in terms of either OS (p=0.88) or FFS (p=0.84) Futility boundaries for both of these endpoints have been exceeded. Toxicities are shown in the table. 18 deaths occurred on the IFL arm during treatment vs. 6 deaths on the FL arm (p=0.008). CONCLUSIONS: In stage III colon cancer, IFL, as compared to FL, is associated with a greater degree of neutropenia, neutropenic fever, and death on treatment, with no associated clinical benefit. Weekly bolus IFL should not be used in the management of stage III colon cancer. [Figure: see text] [Table: see text].

Duke Scholars

Author Donna Niedzwiecki Biostatistics & Bioinformatics, Division of Biostatistics