Patients in any stage of the study with responding disease may receive additional doses of the fCEA-TRI vaccine monthly for 2 months and then every 3 months thereafter. Patients who have objective evidence of response (including mixed response) and/or a fall in an elevated serum CEA level after the sixth vaccine and who subsequently develop disease progression while on the extended every 3-month treatment schedule and have no other potentially better treatment alternatives available may continue treatment as per the monthly vaccination schedule for 2 additional months. Patients with stable or responding disease after those two monthly vaccines may continue monthly vaccines at the discretion of the principal investigator.