title: Colorectal adenocarcinoma: a pediatric case review with a focus on mismatch repair gene mutations and E-cadherin expression.
abstract: Colorectal adenocarcinoma (CRAC) is exceedingly rare in the pediatric population (fewer than 2 cases per 1 million children). There are 2 major categories of pediatric colorectal adenocarcinoma syndromes: polyposis-related and hereditary nonpolyposis colorectal cancer, also known as Lynch syndrome. Germ line mutations in DNA mismatch repair (MMR) genes (eg, MLH1, MSH2, PMS2, MSH6) have been established as the molecular genetic basis of Lynch syndrome. Another prognostic factor in adult CRAC is the reduced expression of epithelial cadherin (E-cadherin), which has been associated with poor outcome in some adult CRAC cases; however, its role in predicting prognoses in pediatric cases remains unclear. Seven pediatric patients with primary CRAC were reviewed. Available molecular genetic test results were evaluated, and immunohistochemical labeling for MMR proteins and E-cadherin were performed on 5 patients. Four of the 5 patients in our study with available paraffin blocks showed loss of MMR protein expression, consistent with Lynch syndrome. In cases stained for E-cadherin, 3 were strongly positive and 2 were weakly positive; however, with the small sample size and the relatively short follow-up period, an accurate correlation between E-cadherin and prognosis cannot be reached with any degree of certainty. Our findings highlight the importance of genetic testing for MMR gene mutations in children with colorectal cancer and suggest further investigation into the prognostic role of E-cadherin in pediatric CRAC.
authors: Department of Pathology, Emory University, Atlanta, GA 30322, USA.
authors: Raul S
authors: RS
authors: Gonzalez
authors: Sarah C
authors: SC
authors: Shulman
authors: Howard M
authors: HM
authors: Katzenstein
authors: Charlotte K
authors: CK
authors: Steelman
authors: Mark L
authors: ML
authors: Wulkan
authors: Carlos R
authors: CR
authors: Abramowsky
authors: Cynthia
authors: C
authors: Cohen
authors: Gigi K
authors: GK
authors: Davis
authors: Bahig M
authors: BM
authors: Shehata
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D000293:Adolescent; D015820:Cadherins / Q000096:biosynthesis*; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D053843:DNA Mismatch Repair / Q000235:genetics*; D005260:Female; D018095:Germ-Line Mutation; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009367:Neoplasm Staging; D055815:Young Adult
chemical_list: D015820:Cadherins