When Angelina Jolie’s double mastectomy hit the headlines in May this year there was a lot of press coverage including discussions about BRCA 1 and 2 genes. These conversations centered on women and their risk of breast or ovarian cancer. But, what about BRCA 1 and 2 in relation to prostate cancer, is there any?
This is an excellent question, but first it would be helpful to understand what are BRCA1 and BRCA2 genes. Why are BRCA genes a problem when they mutate and specifically what does a BRCA gene mutation mean for men?
BRCA1 and BRCA2, found mostly in breast tissue (sometimes referred to as the helping genes) contribute to stopping cells from becoming cancerous by producing proteins that fix damage to the DNA. All of the cells in our body, no matter where they are undergo daily DNA damage and repair which are helped by the BRCA genes. In reality in a single normal day the DNA in each cell can be damaged between 1,000 and 1,000,000 times! Luckily, we’ve evolved very efficient ways to either repair the DNA damage or destroy the un-repairable cells.
An important part of the repair process are the BRCA genes, so any faults or BRCA mutations reduce our ability to repair the DNA damage we suffer in other cells each day. As these mistakes build up in our DNA our chances of our cells becoming cancerous increase.
Since BRCA genes are primarily breast cancer genes, do BRCA mutations only affect women? No, both men and women can inherit a ‘faulty’ BRCA1 or 2 gene from either their mother or father and these mutations can have an effect on everyone.
In women, having a mutation in either BRCA1 or BRCA2 is linked to an increased risk of developing breast or ovarian cancer, and a BRCA2 mutation is thought to confer the bigger risk. Men with BRCA1 or 2 mutations are also at increased risk of developing male breast cancer, although this is still much lower than for women.
So, lets get to prostate cancer and BRCA1 and BRCA2 mutations, do they cause prostate cancer?
No, we don’t yet know of any one gene, or group of genes, that can identify men with, or at high risk of, prostate cancer. Answering this question is important and it needs to be answered, but we do not yet have the answer. We do know that there are a number of locations within the DNA that increase a man’s risk of developing prostate cancer when they contain DNA damage or mistakes.
We know that some of these increased risk locations are within the BRCA1 and 2 genes. However, mutations in BRCA1 and 2 are only found in 0.44% and 1.2% prostate cancer cases respectively. So, while the risk of prostate cancer is increased for men with these mutations, the majority of prostate cancer cases are not linked to BRCA1 or BRCA2 mutations.
Don’t despair if you do have a BRAC mutation because we have two copies of every gene. If you have a BRCA1 or 2 mutation, it means that only one copy of the gene is faulty, but the other one still works perfectly and will allow you to live normally. However, if anything happens to this second working copy of the gene, that’s when DNA damage repair would be affected.
One study suggests that a man with a BRCA1 mutation is 3.4 times more likely to develop prostate cancer by age 65 than a man without this mutation. This is 8.6 times more likely for a man with a BRCA2 mutation.
Is there any evidence that BRCA1 or 2 mutations affect prostate cancer prognosis?
A study at http://www.ncbi.nlm.nih.gov/pubmed/23569316 looked at the effect of BRCA1 and 2 mutations on prostate cancer prognosis specifically the predicted outcome of the disease. This study concluded that prostate cancer in men with a BRCA1 or 2 mutation was more likely to be aggressive and to spread beyond the prostate.
We need to confirm, but the researcher suggests that men who are known to have a BRCA1 or 2 mutation when they are diagnosed with prostate cancer should be treated as high-risk patients immediately.
So, how do I find out if I have a BRAC gene mutation? It is possible to go to a genetic specialist for testing. Genetic testing usually involves taking a vial or two of blood. At the moment there’s not enough evidence to say whether or not being tested for BRCA1 or 2 mutations should be done, even in men with a family history of cancer. If you have a family history of cancer and are concerned about your cancer risk, you should discuss this with your doctors.
Joel T Nowak, M.A., M.S.W.