Colorectal tumour microsatellite instability test results: perspectives from patients.

Purpose: To determine which individuals with colorectal cancer (CRC) were interested in knowing the results of their tumour microsatellite instability (MSI) and immunohistochemistry (IHC) testing. We were also interested in the patients' reasons for choosing to learn their results and in the impact of those results on overall self-assessed quality of life.

Patients And Methods: CRCs from 414 individuals were assayed for MSI and IHC for DNA mismatch repair gene products (MLH1, MSH2, MSH6).