A Prospective Study Of The Prognostic Significance Of Microsatellite Instability In Patients With Early Age-Of-Onset Colorectal Cancer

OBJECTIVES:

• Evaluate the prognostic significance (e.g., overall survival) of microsatellite instability (MSI) status in patients with early age-of-onset stage I-III colorectal cancer, assuming the presence of a quantitative interaction between MSI status and family history of cancer.
• Evaluate the development of metachronous neoplasms in this patient population.
• Evaluate the histologic features and genetic changes associated with hereditary nonpolyposis colorectal cancer in this patient population.

OUTLINE: This is a multicenter study. Patients are stratified according to family history using the Amsterdam II criteria for hereditary nonpolyposis colorectal cancer (positive vs negative).

Patients undergo baseline colonoscopy before or within 6 months of initial curative resection and then surveillance colonoscopy at 1, 3, and 5 years (+/- 6 months) after resection. The number, size, location, histology, and method of removal of polyps are documented at the time of colonoscopy. Patients also undergo microsatellite instability (MSI) status testing and complete family history questionnaires at baseline.

The prognostic significance of family history and MSI status is evaluated. The individual histologic features of the tumors are compared with the MSI status to determine their predictive value. The histologic features are also correlated with outcome to determine their prognostic significance.