Inherited breast and ovarian cancer
On this page
- About inherited breast and ovarian cancer
- Inherited breast and ovarian cancer genes
- Managing a higher risk of breast and ovarian cancer
- Breast screening for women with a higher risk of breast cancer
- Risk-reducing breast surgery
- Risk-reducing bilateral salpingo-oophorectomy
- Risk-reducing drugs for breast cancer
- How we can help
Breast cancer is one of the most common cancers in the UK. It affects 1 in 8 women (around 13%) and 1 in 870 men (around 1%) during their lifetime.
Ovarian cancer is less common. 1 in 52 women (around 2%) will be diagnosed with ovarian cancer during their lifetime.
Many people have someone in their family who is affected by one of these cancers. Only a small number of cases are clearly linked to inherited cancer genes.
An inherited gene mutation that increases the risk of breast and ovarian cancer is more likely if there is a pattern of cancer in your family. These are examples of patterns:
- One of your first-degree relatives was diagnosed with breast cancer before the age of 40. First-degree relatives are your parents, brothers, sisters and children.
- Several family members have been diagnosed with breast cancer or ovarian cancer.
- A male relative was diagnosed with breast cancer.
- A relative had breast cancer in both breasts (bilateral breast cancer).
- You have a family history of cancer and you are from an Eastern European or Ashkenazi Jewish (Eastern European Jewish) background.
If you are worried about the pattern of cancer in your family, start by talking to your GP. If needed, they will refer you to a genetics specialist.
Inherited mutations in several different genes can cause an increased risk of breast and ovarian cancer.
BRCA1 and BRCA2
The genes most often linked to breast and ovarian cancer are called BRCA1 and BRCA2. BRCA is short for BReast CAncer.
Women with an inherited BRCA1 or BRCA2 gene mutation have a higher risk of developing breast or ovarian cancer during their lifetime.
Men can also inherit a BRCA1 or BRCA2 mutation, but they are less likely to develop cancer because of it. They may have a higher than average risk of prostate cancer or breast cancer.
For both men and women, a mutation may also cause a slightly higher than average risk of some other types of cancer.
PALB2, ATM and CHEK2
Women with an inherited mutation in the PALB2, ATM or CHEK2 genes have a moderate risk of developing breast cancer during their lifetime. Women who also have many relatives or younger relatives with breast cancer have a higher risk of developing it. They may also have a slightly higher than average risk of some other types of cancer.
One type of ATM mutation, called c.7271T>G, seems to cause a high risk of breast cancer in women.
Men can also inherit mutations in these genes, but they are less likely to develop cancer because of them.
BRIP1, RAD51C and RAD51D
Women with an inherited mutation in the BRIP1, RAD51C or RAD51D genes have a moderate risk of developing ovarian cancer during their lifetime.
It is not known if it causes a higher risk of other cancer types in women or in men.
Other rare inherited conditions that can increase breast cancer risk in women include:
- Cowden syndrome
- hereditary diffuse gastric cancer
- Li-Fraumeni syndrome
- Peutz Jeghers syndrome
- neurofibromatosis type 1.
These conditions are caused by inherited mutations in genes, including the TP53, CDH1, PTEN and SKT11 genes. There are also likely to be other gene mutations we currently do not know about. This means some families have a clear pattern of breast or ovarian cancer, but genetic tests do not find a mutation.
Genetic Alliance UK offers information and support about rare inherited conditions.
If your family history or genetic test shows you have a higher risk of breast and ovarian cancer, there are ways to reduce that risk. This may include:
- screening tests
Screening tests look for early signs of cancer or for changes that happen before a cancer develops.
- risk-reducing treatments
Women with a high risk of breast and ovarian cancer may be offered:
- surgery to remove the breasts (called risk-reducing breast surgery)
- surgery to remove the ovaries and fallopian tubes (called risk-reducing bilateral salpingo-oophorectomy)
- risk-reducing drug treatment for a number of years.
- being aware of the symptoms of breast and ovarian cancer
Cancer can often be successfully treated, especially when it is found at an early stage. Knowing what is normal for your body means you are more likely to recognise any changes that could be a sign of cancer. We have more information about the possible symptoms of breast cancer and of ovarian cancer. We also have information about possible symptoms of breast cancer in men.
- lifestyle changes
Your genetics specialist can explain if there are factors in your lifestyle that affect your cancer risk. Your genetics specialist, GP or practice nurse can give you more information about healthy living.
Screening for ovarian cancer
So far in the UK, screening is not offered for ovarian cancer. Current screening tests cannot find ovarian cancer early enough to make it more treatable. Researchers are still trying to find the most effective way to screen for ovarian cancer. Some women are offered screening as part of a clinical trial. Your doctor can explain if this is available and the possible risks and benefits of taking part in a clinical trial.
Surgery to remove the ovaries and fallopian tubes reduces the risk of cancer in and near the ovary by over 95%. It may also reduce the risk of breast cancer so may be offered as well as risk-reducing breast surgery to certain women.
Women who decide to have their ovaries removed will start the menopause if they have not already. They will no longer be able to get pregnant. If you want children, you may want to think about having the operation after you have completed your family. Most women who have this operation have it after 35, before the menopause.
After surgery, you usually take hormone replacement therapy (HRT) until the age you would expect to have the menopause. This protects your bone and heart health, and prevents menopausal symptoms. In this situation, HRT does not increase the risk of breast cancer.
Anti-oestrogen drugs can be taken to reduce the risk of developing breast cancer. These drugs reduce the risk of oestrogen receptor-positive (ER positive) breast cancer.
Treatment involves taking a tablet every day for 5 years. For some women, this can reduce the risk of getting breast cancer by 30 to 40%. The drugs most commonly used are tamoxifen and anastrozole or raloxifene.
If you have not been through menopause, you will usually be offered the choice of taking tamoxifen. You need to use contraception while you are taking it. It is not suitable for women who are trying to get pregnant.
Anastrozole and raloxifene can only be used by women who have gone through the menopause.
Side effects of risk-reducing drugs
The most common side effects of risk-reducing drugs are menopausal symptoms. These can include:
- hot flushes
- vaginal discharge and dryness.
Your doctor or nurse will give you more information about possible side effects.
Tamoxifen can also slightly increase your risk of womb cancer and blood clots. These problems are more common in women who take tamoxifen after they have gone through the menopause.
Anastrozole and exemestane can increase the risk of bone thinning (osteoporosis). Tamoxifen can also increase this risk when taken before the menopause. Women at risk of osteoporosis are usually given drugs to help protect their bones.
Women with a BRCA1 gene change do not generally get ER positive breast cancer. So if you have a BRCA1 gene change, risk-reducing drugs may not be as effective.