title: Familial transitional cell carcinoma.
abstract: OBJECTIVE
  Bladder cancer is a common malignancy, and a frequent cause of urological consultation and surgical intervention. Except for smoking and certain occupational exposures, the etiology of bladder cancer is largely unknown. Although the majority of patients with bladder cancer do not have a family history of transitional cell carcinoma of the urinary tract, the study of familial transitional cell carcinoma may lead to knowledge of the pathogenesis of this disease.
  
  
  METHODS
  To evaluate the current understanding of familial transitional cell carcinoma, we reviewed the contemporary literature for case reports and epidemiological studies about this disease.
  
  
  RESULTS
  Numerous case reports document the clustering of transitional cell carcinoma in families, several of which demonstrate an extremely early age at onset of disease, which argues in favor of a genetic component to familial transitional cell carcinoma. The results of large epidemiological studies also suggest the existence of familial transitional cell carcinoma, and first degree relatives appear to have an increased risk for disease by a factor of 2. Familial clustering of smoking does not appear to be the cause of this increased risk.
  
  
  CONCLUSIONS
  Familial transitional cell carcinoma may be the result of a genetically transmitted predisposition to disease, at least in some affected families. Further studies are required to identify candidate genes that may be responsible for this form of bladder cancer.
authors.affiliation: James Buchanan Brady Urological Institute, Department of Urology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Kiemeney
authors.forename: M
authors.initials: M
authors.lastname: Schoenberg
mesh_terms: D002295:Carcinoma, Transitional Cell / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D001749:Urinary Bladder Neoplasms / Q000453:epidemiology / Q000235:genetics*