title: Clustering of colorectal cancer in families of probands under 40 years of age.
abstract: Although sporadic colorectal cancer (CRC) is relatively uncommon in the young, it may constitute an elevated genetic risk for CRC in these individuals.
  
  
  OBJECTIVE
  This study was designed to determine extent of colorectal cancer in families of probands under 40 years of age.
  
  
  METHODS
  Medical records of all consecutive patients, 40 years of age or younger at the time of CRC surgery, during the time period 1986 to 1994 were examined. Cases of familial adenomatous polyposis and ulcerative colitis were excluded. Via interviews of surviving probands or nearest relatives, dates of birth and death, causes of death, and diagnosis of cancer were recorded on all first-degree relatives (parents, siblings, and offspring), second-degree relatives (grandparents, aunts, and uncles), and any other relatives.
  
  
  RESULTS
  A total of 128 patients, 40 years of age or less at time of CRC resection, were identified. Of these, 45 probands/families were reached by phone, and 45 detailed family histories were obtained. Age range of these 45 probands was 19 to 40 (mean, 33.1) years. In 25 families there was no history of CRC in first-degree, second-degree, or third-degree relatives. Eight of 45 probands (17.8 percent) had at least one first-degree relative with CRC, and three of these eight families fulfilled the Amsterdam criteria for hereditary nonpolyposis colorectal cancer (HNPCC). In all three families, inheritance of CRC appeared to segregate with the maternal side of the family. In addition, 5 of 43 non-HNPCC probands had at least one first-degree, second-degree, or third-degree relative less than 40 years of age, at time of CRC diagnosis.
  
  
  CONCLUSIONS
  Ascertainment of a detailed family history in early age of onset CRC patients identifies frequent familial clustering of CRC and HNPCC in 17.8 percent of cases.
authors.affiliation: Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Guillem
authors.forename: A L
authors.initials: AL
authors.lastname: Bastar
authors.forename: J
authors.initials: J
authors.lastname: Ng
authors.forename: J L
authors.initials: JL
authors.lastname: Huhn
authors.forename: A M
authors.initials: AM
authors.lastname: Cohen
mesh_terms: D000328:Adult; D016000:Cluster Analysis; D015179:Colorectal Neoplasms / Q000235:genetics*; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D010375:Pedigree