Potential Predictive Biomarkers in Patients Undergoing First-line Chemotherapy for Metastatic Colorectal Cancer

Inclusion Criteria Histologically confirmed metastatic colorectal cancer Unresectable metastatic disease must be confirmed histologically if \> 2 years since primary diagnosis Measurable metastatic disease \> 1 cm by spiral CT scan or \> 2 cm by other methods Scheduled to receive first-line chemotherapy for metastatic disease Chemotherapy must include fluorouracil, capecitabine, irinotecan hydrochloride, or oxaliplatin Exclusion Criteria Inadequate or unusable tissue as the only tissue available Brain metastases or meningeal disease Contraindication to chemotherapy Pregnant or nursing Other severe pathology that is likely to worsen during therapy Dementia or severely impaired mental condition Geographical or psychological reasons that would preclude treatment