Lymphatic Mapping, Sentinel Lymph Node Analysis, and Blood Tests in Detecting and Predicting Early Micrometastases in Patients With Colorectal Cancer

RATIONALE: Diagnostic procedures, such as lymph node mapping during surgery and sentinel lymph node biopsy, may help doctors find micrometastases and predict cancer recurrence.
PURPOSE: This phase II trial is studying how well lymph node mapping during surgery together with sentinel lymph node analysis and blood testing work in detecting and predicting early micrometastases in patients with colorectal cancer.