Inherited Predisposition and Prostate Cancer
Within the medical community, it is recognised that a family history of prostate cancer can increase an individual’s chance of developing the disease. Evidence from several studies show that the risk to an individual increases as the number of blood relatives on one side of the family affected by prostate cancer increases, and as the age of diagnosis of an affected family member decreases. Risk also depends on how closely related affected family member(s) are.
It has been estimated that between 5% and 15% of prostate cancer cases can be attributed to the inheritance of gene alterations, but discovering which genes are responsible has proven to be extremely difficult. Unlike other common cancers where a small number of high-risk genes account for a large proportion of high-risk families, it is thought that an inherited predisposition to prostate cancer can be caused by a number of different genes. So far, scientists have discovered several potential prostate cancer predisposition genes, and research is underway to either confirm or dismiss the role that these genes play in prostate cancer development.
It is, however, thought highly likely that a family history of breast and ovarian cancer could increase an individual’s chance of developing prostate cancer, and a link between prostate cancer development and the Breast Cancer predisposition genes BRCA1 and BRCA2 has been proposed. BRCA1 and BRCA2 play a major role in hereditary breast and ovarian cancer, and it has been noted that several families which carry alterations in these particular genes (and as a result have a high breast and ovarian cancer incidence), have a higher than average number of prostate cancer cases.
IMPACT is a new international study which is investigating the role that the BRCA1 and BRCA2 gene alterations play in prostate cancer development. It is currently recruiting participants within the UK, and is looking for men from families which are known to carry BRCA1 or BRCA2 gene alterations (please note both men who carry the gene alterations, and men who have had a negative test result and who therefore do not carry the gene alteration, are eligible for this study). You can read more about this study if you visit the about IMPACT section of this website.
As discussed, it is thought that there are several other genes which may play a role in inherited predisposition and prostate cancer. In some international populations there have been reports that alterations within specific genes such as CHEK2, NBS1 and ATM can also predispose to the disease. Researchers are currently following these leads in other populations, to determine if these genes do confer an increased risk in other countries. It seems that in some international populations, alterations in these genes can confer an increased prostate cancer risk, but this may not be true for all countries. Although at the moment IMPACT is only recruiting carriers of alterations in the BRCA1 and BRCA2 genes, in some countries carriers of other gene alterations may be included as further information about these alterations becomes available.
It should be noted that not every one who has an inherited predisposition will go on to develop cancer. If, however, you are worried about your own family history of cancer, then please visit the Genetics and Cancer: what can I do? section of this website for advice.
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