Bortezomib in Treating Patients With Metastatic or Recurrent Colorectal Cancer

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed adenocarcinoma of the colon or rectum that is incurable with conventional therapy Metastatic or recurrent disease At least 1 unidimensionally measurable lesion At least 20 mm by conventional techniques or at least 10 mm by spiral CT scan Disease must be accessible to biopsy No known brain metastases PATIENT CHARACTERISTICS: Age 18 and over Performance status ECOG 0-1 OR Karnofsky 70-100% Life expectancy More than 3 months Hematopoietic Absolute granulocyte count at least 1,500/mm^3 WBC at least 3,000/mm^3 Platelet count at least 100,000/mm^3 Hepatic Bilirubin no greater than 1.25 times upper limit of normal (ULN) AST or ALT no greater than 3 times ULN (less than 5 times ULN if liver metastases present) Renal Creatinine no greater than 1.25 times UNL OR Creatinine clearance at least 50 mL/min Cardiovascular No symptomatic congestive heart failure No unstable angina pectoris No cardiac arrhythmia Other Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No psychiatric illness or social situation that would preclude study compliance No other uncontrolled concurrent illness No ongoing or active infection No other active malignancy within the past 3 years except curatively treated nonmelanoma skin cancer or carcinoma in situ of the cervix No grade 1 or greater peripheral neuropathy due to prior chemotherapy No significant traumatic injury within the past 21 days PRIOR CONCURRENT THERAPY: Biologic therapy Not specified Chemotherapy No more than 1 line of prior chemotherapy (including any combination of fluorouracil, irinotecan, and/or oxaliplatin) for metastatic disease At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered Prior adjuvant chemotherapy allowed No concurrent cytotoxic chemotherapy Radiotherapy More than 4 weeks since prior radiotherapy and recovered No prior radiotherapy to measurable target lesion unless disease progression has occurred after radiotherapy No concurrent radiotherapy to the sole site of measurable disease Surgery More than 21 days since prior major surgery Other No other concurrent investigational agents No concurrent combination antiretroviral therapy for HIV-positive patients