RATIONALE: Genetic studies may help in understanding the genetic processes that cause some types of cancer.

PURPOSE: Genetic trial to study certain genes of patients who have stage II or stage III colon cancer.

OBJECTIVES:

• Determine the adverse prognostic significance of 8p allelic imbalance (AI) in patients with colon cancer.
• Determine if patient prognosis is dependent on the region of 8p AI.
• Perform fine mapping studies to further localize the putative tumor suppressor gene(s) on 8p.
• Perform multicolor FISH to examine the role that 8p loss and 8q gain play in the prognosis of patients whose tumors exhibit 8p AI.

OUTLINE: Matched normal and tumor DNA is analyzed for 8p allelic imbalance with at least 8 markers: D8S262 and D8S1825 localized to 8p23, D8S254 and D8S261 at 8p22, D8S560 and D8S136 at 8p21, and D8S1820 and D8S283 at 8p12. Normal/tumor tissue pairs are used for fine mapping studies.

DISEASE CHARACTERISTICS:

• Diagnosis of resectable stage II or III adenocarcinoma of the colon
• Participated in NCCTG-914653
• DNA extracted from both normal and tumor tissue

PATIENT CHARACTERISTICS:

Age

• Under 70

Patients with advanced colon cancer previously participating in NCCTG-914653.