HealthInfo Canterbury
Inherited cancer & BRCA genes
About 5% of breast cancer and 15% of one type of ovarian cancer is inherited, meaning it's passed down in families.
People who get inherited cancer (also called familial cancer) have an error or mutation in their genes. Women who have a mutation are more likely to get breast or ovarian cancer. Men with a mutation are more likely to get prostate cancer (mainly in their 40s and 50s) and breast cancer.
BRCA1 and BRCA2 (pronounced "bracka" one and two) are the most common genes to have a mutation causing breast and ovarian cancer.
BRCA genes
BRCA1 and BRCA2 are genes that help to repair your DNA. If your BRCA genes have a mutation, you don't repair damaged DNA properly, which increases your risk of getting breast and ovarian cancer.
Testing for faulty genes
It's quite rare to have a BRCA gene mutation. Only about one in every 800 people has a mutation, so not everyone should be tested for this or other genes that cause cancer.
But there are thousands of possible mutations, so it's best to start testing with a family member who has or has had breast or ovarian cancer. If tests find they have a specific gene mutation, other family members can be tested to see if they have the same one.
You're more likely to have a BRCA or other breast cancer gene mutation if you or someone in your family has had:
- breast or ovarian cancer before the age of 40
- triple negative breast cancer before the age of 50
- breast cancer in both breasts
- breast cancer in a man
- high-grade epithelial ovarian cancer
- breast and ovarian cancer.
It is also more common if you have Ashkenazi Jewish ancestors.
If any of these apply to you, speak to your GP. They can refer you to the Genetic Health Service see if you should be tested for a gene mutation.
Faulty genes and cancer
Not everyone with a BRCA or other breast cancer gene mutation will get cancer but your chances of getting breast and ovarian cancer are much higher than people who don't have the mutation.
If you or your partner has a BRCA mutation, your children each have a 50% chance of having the same mutation.
Next steps
If you have a BRCA gene mutation, there are ways to reduce your chances of getting breast or ovarian cancer. These include getting risk-reducing surgery, regular mammograms and regular examinations by a breast surgeon.
There is no way to screen for ovarian cancer so it's recommended that women who have finished their families and are aged around 40 have their ovaries and fallopian tubes removed. This removes the risk of getting ovarian cancer but means that you'll start menopause younger than most women. Your doctor will refer you to a gynae-oncologist for this.
As with all cancers, stopping smoking, having a healthy diet and lifestyle and not being overweight may also reduce your risk.
If you have any more questions about BRCA or other cancer gene testing, talk to your GP.
Written by HealthInfo clinical advisers. Last reviewed December 2021.
SourcesReview key: HICCR-38555
