Matrix Metalloproteinases After Surgery and/or Radiofrequency Ablation in Patients With Liver Metastases From Colorectal Cancer

RATIONALE: Studying samples of blood from patients with cancer in the laboratory may help doctors learn more about changes that occur in DNA and identify biomarkers related to cancer. It may also help doctors predict how patients will respond to treatment.
PURPOSE: This research trial is studying matrix metalloproteinases after surgery or radiofrequency ablation in patients with liver metastases from colorectal cancer.