UPDATE ARTICLES/COMMENTARIES: PDF OnlyMismatch Repair Proteins and Microsatellites Hit Clinical PracticeStahl, Jürgen Author Information On: Choice of management strategy for colorectal cancer based on a diagnostic immunohistochemical test for defective mismatch repair. Cawkwell L, Gray S, Murgatroyd H, Sutherland F, Haine L, Longfellows M, O'Loughlin D, Kronberg O, Fenger C, Mapstone N, Dixon M, Quirke P. Gut 1999;45:409-15 At the Department of Anatomical Pathology, School of Medicine, Flinders University, Adelaide, South Australia. Advances in Anatomic Pathology: March 2000 - Volume 7 - Issue 2 - p 85-93 Buy Abstract Summary: Hereditary nonpolyposis colon cancer (HNPCC) is one of the most common familial cancers with characteristic molecular changes that are different from those found in familial adenomatous polyposis (FAP) coli. Genetic mutations in the germline and somatic cells lead to loss of expression of one of the two most commonly involved mismatch repair genes, hMSH2 or hMLH1, and consequently, to expansion of certain repetitive DNA sequences (microsatellite instability (MSI). The paper describes a distinct subtype of “HNPCC-like” sporadic colonic carcinoma that can easily be identified by immunohistochemistry. Recognition of this subtype of colonic cancer is important because it occurs in the younger age group and is associated with better survival, but also a five-fold chance of developing a second colorectal carcinoma compared to “conventional” colorectal carcinomas. © 2000 Lippincott Williams & Wilkins, Inc.