title: p53 polymorphism and age of onset of hereditary nonpolyposis colorectal cancer in a Caucasian population.
abstract: OBJECTIVE
  Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal dominant syndrome of familial malignancies. Colorectal and endometrial cancers are most frequently observed. The syndrome results mainly from germ-line mutations in DNA mismatch repair genes. A common G-to-C polymorphism at codon 72 in the p53 gene has been associated with increased risk for lung, nasopharyngeal, oral, prostate, and breast cancers and may be a marker for genetic susceptibility to colorectal cancer. We studied the influence of this p53 polymorphism on HNPCC age of onset.
  
  
  METHODS
  We determined the p53 genotype of 92 Caucasian mismatch repair mutation carriers, of which, 47 had colorectal cancer. The subjects were genotyped by single-strand conformational polymorphism analysis. We tested the association between age of onset and the p53 genotypes by comparing Kaplan-Meier survival curves, evaluating the homogeneity of the curves using the log-rank test and Wilcoxon's test, and estimating the association using the Cox proportional hazards regression model to adjust for potential demographic confounding factors.
  
  
  RESULTS
  The HNPCC patients who were heterozygous developed their colorectal cancer 13 years earlier than HNPCC patients who were homozygous for the wild-type allele.
  
  
  CONCLUSIONS
  Combining knowledge of an individual's p53 genotype with information on other genetic and environmental risk factors may improve risk estimates and help to identify individuals who are genetically susceptible to developing HNPCC at an earlier age.
authors.affiliation: Department of Epidemiology, University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA.
authors.forename: J Shawn
authors.initials: JS
authors.lastname: Jones
authors.forename: Xuedong
authors.initials: X
authors.lastname: Chi
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Gu
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Lynch
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Amos
authors.forename: Marsha L
authors.initials: ML
authors.lastname: Frazier
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002352:Carrier Proteins; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000453:epidemiology / Q000235:genetics*; D004252:DNA Mutational Analysis; D004260:DNA Repair; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D016158:Genes, p53 / Q000235:genetics*; D005828:Genetics, Population; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic / Q000235:genetics*; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012307:Risk Factors; D044465:White People / Q000235:genetics*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D004273:DNA, Neoplasm; 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