DISEASE CHARACTERISTICS: Histologically proven metastatic and/or locally recurrent adenocarcinoma of the colon or rectum that is not expected to be cured with standard therapy Patients who previously underwent definitive surgical resection and subsequently develop metastatic disease should have diagnosis reconfirmed with new histologic or cytologic specimen if: More than 5 years have elapsed since primary surgery OR Primary tumor was stage I or II At least 1 measurable lesion (2 cm or more in widest diameter) by CT or MRI scan No CNS metastases