OUTLINE: This is a multicenter study. Patients are stratified by response to irinotecan based chemotherapy regimen (stable disease vs disease progression). Patients receive a test dose of cetuximab IV over 10 minutes on day 1. Patients who do not experience grade 4 anaphylactic reaction receive a loading dose of cetuximab IV over 2 hours beginning 30 minutes after completion of test dose. Patients receive maintenance cetuximab IV over 1 hour on days 8, 15, 22, 29, and 36. Patients receive irinotecan IV over 90 minutes (beginning 1 hour after completion of cetuximab infusion) at the same regimen (dosage and frequency) on which the patient became refractory to irinotecan therapy. Irinotecan is administered at a higher dose on days 1 and 22 OR at a lower dose on days 1, 8, 15, and 22. Courses repeat every 6 weeks in the absence of disease progression or unacceptable toxicity. Patients with unacceptable toxicity to irinotecan may continue on cetuximab maintenance therapy alone at the discretion of the protocol investigator and sponsor. Quality of life is assessed before initiation of study therapy, at the completion of each course, and then at 4 weeks after completion of study. Patients are followed at 4 weeks.