title: Families at risk for colorectal cancer: risk assessment and genetic testing.
abstract: As befits a common cancer, a family history of colorectal cancer (CRC) is reported by about 10% of individuals. The discovery of the genetic basis of hereditary nonpolyposis CRC and familial adenomatous polyposis has opened up the possibility for determining genetic predisposition to CRC in asymptomatic family members of affected cases. This article reviews the information needed for accurate risk assessment for those with a family history of CRC. Screening recommendations and the current status of genetic testing, including review of available tests such as microsatellite instability, immunohistochemistry for hMSH2 and hMLH1, testing for I1307K, and gene testing for germline mutations in hMSH2 and hMLH1 are discussed. At the current time, reliable, informative genetic testing, capable of application to broad segments of the population, is an unrealized goal. But as the methodology for testing improves and as better appreciation of the significance and meaning of a positive or negative test result ensues conditions for increased use of genetic testing could emerge.
authors.affiliation: Department of Medicine, University of Pittsburgh Medical Center, Pennsylvania, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Schoen
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D018256:Adenomatous Polyps / Q000235:genetics; D000328:Adult; D000367:Age Factors; D000368:Aged; D000465:Algorithms; D020137:Base Pair Mismatch; D002352:Carrier Proteins; D002648:Child; D015331:Cohort Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000235:genetics*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics; D004260:DNA Repair; D004268:DNA-Binding Proteins; D005260:Female; D017491:Genes, APC / Q000235:genetics; D020022:Genetic Predisposition to Disease; D005820:Genetic Testing; D006801:Humans; D007150:Immunohistochemistry; D007585:Jews / Q000235:genetics; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D009154:Mutation; D009363:Neoplasm Proteins / Q000032:analysis; D009687:Nuclear Proteins; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000032:analysis; D012306:Risk; D018570:Risk Assessment
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C501486:MLH1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein