title: Hereditary and familial ovarian cancer in southern Ontario.
abstract: BACKGROUND
  Hereditary ovarian cancer may be site specific or may appear in combination with breast cancer or other cancers in a family. The most common hereditary form is the breast-ovarian cancer syndrome. It is estimated that in 100% of these families, there is linkage to a cancer susceptibility gene on chromosome 17q, BRCA1.
  
  
  METHODS
  A positive family history of breast or ovarian cancer was reported for 71 of 450 unselected cases of ovarian cancer identified in Southern Ontario. Detailed pedigrees were completed by telephone interview for 48 of the 71 subjects.
  
  
  RESULTS
  Nine families were identified with five or more cases of breast or ovarian cancer, 14 families with four cases of cancer, and eight families with three cases. Breast cancer appeared in 80% of the ovarian cancer families. There were 81 healthy first-degree female relatives of the cancer cases considered to be at high risk for ovarian cancer.
  
  
  CONCLUSIONS
  It is feasible to use a simple questionnaire on all incident cases of ovarian cancer in a population to identify families with potential hereditary breast-ovarian cancer. Two point nine percent to 6.9% of cases of ovarian cancer appear to be inherited; the majority of the families also will have an excess number of cases of breast cancer.
authors.affiliation: Department of Medicine, McGill University, Montreal, Canada.
authors.forename: S A
authors.initials: SA
authors.lastname: Narod
authors.forename: L
authors.initials: L
authors.lastname: Madlensky
authors.forename: L
authors.initials: L
authors.lastname: Bradley
authors.forename: D
authors.initials: D
authors.lastname: Cole
authors.forename: P
authors.initials: P
authors.lastname: Tonin
authors.forename: B
authors.initials: B
authors.lastname: Rosen
authors.forename: H A
authors.initials: HA
authors.lastname: Risch
mesh_terms: D000328:Adult; D000368:Aged; D019313:BRCA1 Protein; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D002886:Chromosomes, Human, Pair 17; D005260:Female; D030342:Genetic Diseases, Inborn / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics; D009378:Neoplasms, Multiple Primary / Q000453:epidemiology / Q000235:genetics*; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000235:genetics*; D009864:Ontario / Q000453:epidemiology; D010051:Ovarian Neoplasms / Q000453:epidemiology / Q000235:genetics*; D010375:Pedigree; D014157:Transcription Factors / Q000235:genetics
chemical_list: D019313:BRCA1 Protein; D009363:Neoplasm Proteins; D014157:Transcription Factors