title: Microsatellite instability in sporadic colon cancer is associated with an improved prognosis at the population level.
abstract: Some previous studies have reported an improved prognosis in sporadic colon cancers with microsatellite instability, whereas others have not. In addition, relatively few of those reporting an improved prognosis controlled for tumor stage or were population-based. Therefore, we evaluated the relationship between microsatellite instability and prognosis, tumor stage, and other clinical variables in a population-based study of 1026 individuals. Microsatellite instability was determined by the noncoding mononucleotide repeat BAT-26 and the coding mononucleotide repeat in transforming growth factor-beta receptor type II. Significant relationships were seen between microsatellite instability and proximal tumor location, female gender, young and old age at diagnosis, poor histological differentiation, and low tumor stage (P < 0.01). There was a significant relationship between microsatellite instability and improved prognosis, even after adjusting for stage, with a reduction in the risk of death attributable to colon cancer of approximately 60%. Most of this risk reduction occurred in individuals with American Joint Committee on Cancer stage III tumors, although transforming growth factor-beta receptor type II mutations were associated with a significant reduction in colon cancer death in tumors with distant metastases. We conclude that microsatellite instability in sporadic colon cancer is associated with an improved prognosis at the population level.
authors.affiliation: Departments of Pathology, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA. wsamowitz@msscc.med.utah.edu
authors.forename: W S
authors.initials: WS
authors.lastname: Samowitz
authors.forename: K
authors.initials: K
authors.lastname: Curtin
authors.forename: K N
authors.initials: KN
authors.lastname: Ma
authors.forename: D
authors.initials: D
authors.lastname: Schaffer
authors.forename: L W
authors.initials: LW
authors.lastname: Coleman
authors.forename: M
authors.initials: M
authors.lastname: Leppert
authors.forename: M L
authors.initials: ML
authors.lastname: Slattery
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002140:California / Q000453:epidemiology; D003110:Colonic Neoplasms / Q000235:genetics* / Q000401:mortality*; D005260:Female; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics; D012737:Sex Factors; D016019:Survival Analysis; D014589:Utah / Q000453:epidemiology
chemical_list: D018125:Receptors, Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; D000077294:Receptor, Transforming Growth Factor-beta Type II