title: Clinicopathologic factors identify sporadic mismatch repair-defective colon cancers.
abstract: Identification of sporadic mismatch repair (MMR)-defective colon cancers is increasingly demanded for decisions on adjuvant therapies. We evaluated clinicopathologic factors for the identification of these prognostically favorable tumors. Histopathologic features in 238 consecutive colon cancers were linked to MMR status based on immunostaining and BRAF mutation status.MMR defects were identified in 22.7% of the tumors, with 46 classified as sporadic. When the clinical parameters of age, sex, and proximal tumor location were combined with the morphologic features with the highest relative risks (RRs), eg, mucinous differentiation (RR, 9.0), tumor-infiltrating lymphocytes (RR, 7.5), absence of necrosis (RR, 7.5), and expanding growth pattern (RR, 5.0) into a 7-factor index, the presence of at least 4 features identified the MMR-defective tumors with 92.3% sensitivity and 75.3% specificity and excluded 61.5% of the tumors from MMR testing. This clinicopathologic index thus successfully selects MMR-defective colon cancers.
authors.affiliation: Department of Pathology and Cytology, Helsingborg Hospital, Sweden.
authors.forename: Britta
authors.initials: B
authors.lastname: Halvarsson
authors.forename: Harald
authors.initials: H
authors.lastname: Anderson
authors.forename: Katarina
authors.initials: K
authors.lastname: Domanska
authors.forename: Gudrun
authors.initials: G
authors.lastname: Lindmark
authors.forename: Mef
authors.initials: M
authors.lastname: Nilbert
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D053843:DNA Mismatch Repair; D004252:DNA Mutational Analysis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics* / Q000378:metabolism; D012737:Sex Factors
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf