Utility of immunohistochemistry for mismatch repair proteins on colorectal polyps in the familial cancer clinic

Abstract

Background: Immunohistochemistry for loss of expression of one or more of the mismatch repair proteins is performed on colorectal cancer tissue as a screening test for Lynch syndrome; however, its role in pre-malignant polyps remains controversial. Aim: To determine the effectiveness of mismatch repair immunohistochemistry performed on pre-malignant colorectal polyps in identifying Lynch syndrome, focusing on clinical utility and value. Methods: A retrospective audit was conducted of mismatch repair immunohistochemistry performed on non-malignant polyps in patients who attended the Family Cancer Clinic at the Royal Melbourne Hospital. Two hundred and six patient records over a 10-year period..