Cancer risks in A-T heterozygotes

Int J Radiat Biol. 1994 Dec;66(6 Suppl):S177-82. doi: 10.1080/09553009414552011.


It is well established that ataxia-telangiectasia (A-T) patients suffer a grossly elevated risk of cancer, particularly lymphoma and leukaemia, but the possibility of an excess cancer risk of cancer in heterozygotes carriers of A-T mutations is more controversial. A number of studies indicate that female relatives of A-T patients suffer excess risk of breast cancer; based on an overview of all currently available data the estimated relative risk of breast cancer to A-T heterozygotes is 3.9-fold (95% CI 2.1-7.2). There is some suggestion that relative risk declines with age. In contrast, there is no consistent evidence of a risk from any other cancer; the estimated risk from all studies is 1.9 (95% CI 1.5-2.5) but some studies show a larger effect whilst others show no excess risk. On the basis of these results and the likely frequency of the A-T gene, A-T heterozygotes would account for between 1 and 13% of breast cancer cases, with 3.8% being the best estimate. However, unless the breast cancer risk has been seriously underestimated, the A-T gene will make little contribution to familial breast cancer.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adult
  • Aged
  • Ataxia Telangiectasia / complications*
  • Ataxia Telangiectasia / genetics*
  • Breast Neoplasms / etiology
  • Breast Neoplasms / genetics*
  • Family Health
  • Female
  • Heterozygote*
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / epidemiology*
  • Neoplasms / etiology
  • Neoplasms / genetics
  • Risk Factors
  • United Kingdom / epidemiology