Inheriting the breast cancer gene - what doctors want you to know about the chances, risks and testing
Breast cancer can be passed down genetically, but there are other important factors to consider…
Breast cancer is the most common form of cancer in the UK - and it’s likely that you are already aware of its heartbreaking impact on families. Statistics show one woman is diagnosed every ten minutes, leading to around 55,000 cases and 11,500 deaths annually.
However, you may be less aware of inherited breast cancer. According to Breast Cancer UK, 15% of people with the condition have a family history of the disease - and inherited mutations in genes account for about 4-6% of all cases.
Just because you may carry the gene mutation, it doesn’t necessarily mean you will develop the condition. A number of factors - including lifestyle - can impact your chances. It's now possible to find out about your own predisposition to breast cancer - so you can take steps to reduce your risk. Celebrities, including Angelia Jolie, Christina Applegate, Anastasia and Sharon Osbourne underwent preventative mastectomies after finding they had the genetic mutations. However testing is an emotional decision that should be carefully considered.
If inherited breast cancer is on your mind for whatever reason, seek support from a healthcare professional - and stay up-to-date with the latest NHS advice
How do genes affect your breast cancer risk?
“There are two primary genes associated with breast cancer – BRCA1 and BRCA2,” says Dr Tim Woodman, medical director of cancer and policy at Bupa. “While everyone has these genes, a fault or mutation can increase the chances of developing breast cancer. A person can inherit a mutation from either their mother or father at birth."
If one parents has the faulty gene, you have a 50% chance of inherting it. "If both parents have faulty BRCA genes, your chance of inheriting them increases to 100%.” adds Dr Woodman.
Carrying a BRCA gene mutation doesn't guarantee you will develop breast cancer, but it does increase your risk. For example, while the general risk for a woman born after 1960 is 14%, it jumps to 45-70% for those with a BRCA mutation
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Several other factors contribute, including hormones and lifestyle choices. “About 5-10% of all breast cancers may be linked to an inherited gene variant - the vast majority occur by chance,” points out Dr Charlie Chan, consultant surgeon at Nuffield Health Cheltenham Hospital.
Can you be tested for the breast cancer gene?
“An increasing proportion of breast cancer patients are being offered genetic testing,” explains Dr Chan. “If a close family member has been diagnosed with a breast cancer gene variant, other family members may be offered testing.
If a close family member has been affected by the condition, you should speak to a healthcare professional. “It is best to discuss family history concerns with your GP first,” explains Dr Chan. “They can refer you to your nearby family history breast cancer clinic or genetics service. It is important to gather as much information about your family tree before seeing a specialist.
“If the family history risk is high enough to consider genetic testing - which is normally performed either with a saliva sample or with a blood test - it is crucial that you are counselled fully before the test is done. In particular, it is important to explore what you might do if testing showed a positive result."
Pros and cons of knowing your genetic risk
Knowing your genetic risk may bring you comfort. It could encourage you to seek earlier treatment and make better lifestyle choices that could reduce your risk of developing the illness.
“However, some people may find the results of their test more difficult to cope with", says Dr Woodman. "Especially if a faulty gene is found, and they have to let other family members know. It’s important to remember that genetic testing simply highlights your risk – it won’t tell you for certain whether you’ll develop breast cancer, so making positive lifestyle choices can have a real impact on reducing that risk.”
“It is crucial you have expert genetic counselling prior to a test,” insists Dr Chan. “It is important for you to consider what you might do, if the test result were to show that you’re carrying an abnormal breast cancer gene. It is also important to discuss the potential impact on the rest of the family”
When to tell children (and how)
“Speaking to your child about breast cancer genetic testing can be difficult, especially if it’s prompted by a family member experiencing the condition,” notes Dr Woodman. “Children under the age of 18 can’t be tested for faulty breast cancer genes, as they need to know the full implications and be old enough to make an informed decision. However, learning about genetic testing from parents can be a good way to introduce a conversation about accountability and prevention.”
Dr Chan agrees: “There is no single right or wrong way to discuss a breast cancer gene finding with children. Studies have shown that most parents report their children were not concerned after discussing a their BRCA result.” However, he adds, ensure that the setting is right for you to share such sensitive information with a child - including the place and time of day.
“Take a gradual approach with age-appropriate language,” recommends Dr Chan. “Be open and honest, as well as encouraging questions and ongoing discussion.” You can also seek emotional support for your child from their school, a family health professional or charities like Jeans For Genes.
3 ways to lower your cancer risk if you have the gene
1. Healthy lifestyle choices
"If you find out that you have a faulty breast cancer gene, it may encourage you to look at your lifestyle choices and make changes that could lead to a lowered risk,” notes Dr Woodman. “Along with making sure you’re eating healthily and doing at least 150 minutes of moderate intensity exercise each week, it’s useful to avoid certain things that could increase your chance of getting breast cancer.” This includes stopping smoking and not drinking more alcohol than the daily recommended units.
Dr Woodman continues: “Those with a faulty BRCA gene should avoid becoming overweight, and also consider stopping taking the oral contraceptive pill and look at alternative forms of contraception.” It is also recommended to discuss hormone replacement therapy (HRT) use with a doctor.
2. Preventive surgeries and treatments
“Some women with a known breast cancer gene may benefit from some medicines or surgeries that may help reduce their risk of developing the disease,” says Dr Woodman. “A health professional or genetic counsellor will discuss what your options are and their potential side effects.
“Your healthcare professional may recommend medicines such as anastrozole, tamoxifen or raloxifene. For some women, this can reduce their risk of getting breast cancer for years. Others may also consider surgery - such as a preventative mastectomy, where the breasts are removed, can reduce their risk of developing breast cancer by around half.”
Dr Woodman notes: “However, having a preventative mastectomy is major surgery, so deciding to have one shouldn’t be taken lightly, as the recovery can be physically and emotionally demanding.” Similarly, Dr Chan adds: “It is important to recognise that these operations reduce the likelihood, but cannot remove the risk of cancer completely.”
3. Regular check-ups and screenings
“If a woman is found to have an abnormal breast cancer gene, normally she would be offered enhanced screening,” explains Dr Chan. “This would usually be annual MRI scanning for women under the age of 35 - after this age, it will be in the form of annual mammograms.”
Further support
You can find out more information about inherited breast cancer from a number of charities, including Breast Cancer UK, Cancer Research UK, Breast Cancer Now, CoppaFeel! and the National Hereditary Breast Cancer Helpline.
There is a list of resources - including books - compiled by Cancer Research UK. Meanwhile, Breast Cancer UK hosts The B Well Club Podcast.
Frequently asked questions
Can you still get breast cancer if you don't have the gene?
“You can still get breast cancer even if you don’t have a faulty breast cancer gene,” says Dr Woodman, referring to the vast majority of cases. “It’s not always clear why someone develops breast cancer and another person doesn’t, but we know that there are several things that can increase your likelihood - thought to be a combination of genetics, hormones and lifestyle.
“Known factors that have been linked to a raised risk include being aged 50 or over, having a close relative - such as a parent or sister - who has had breast or ovarian cancer, starting your periods early, starting menopause late, never having a child, having a child after the age of 30, taking any kind of hormonal contraception pill, or having the hormonal coil fitted, being overweight in menopause and drinking alcohol to excess.”
Is inherited breast cancer more aggressive?
“Inheriting faulty breast cancer genes can leave you more susceptible to more aggressive forms of breast cancer,” says Dr Woodman. “For example, a faulty BRCA1 gene is linked to developing triple-negative breast cancer. The chances of developing breast cancer from a faulty BRCA gene are low though – only 10% of women diagnosed have the gene mutation.”
Which parents passed the breast cancer gene
“The breast cancer genes can be passed down by either parent, from either a mother or a father,” confirms Dr Chan. If both carried the gene, then your chance of inheriting it from them is 100 per cent.
Dr Tim Woodward is the medical director of cancer and policy at Bupa Health Insurance. He qualified as a doctor in 1981 from St George’s Hospital, London, and worked as an NHS GP for 15 years, before moving into medical management and then joining Bupa in 2012. He is a member of the European Society for Medical Oncology, and is passionate about using scientific advances - particularly in genomics - to drive quality, safety and clinical effectiveness in cancer care.
Dr Charlie Chan is consultant surgeon specialising in breast disease at Nuffield Health Cheltenham Hospital. He qualified from St Bartholomew's Hospital in London in 1986 and trained in Oxford, where he was a clinical lecturer. His DPhil research was on tumour angiogenesis at the Institute of Molecular Medicine. He has been a NHS consultant at the Royal Bournemouth and Cheltenham General Hospitals, and in 2012 left the NHS to work solely in private practice.
Lauren is a freelance writer and editor, with more than eight years of experience working in digital and print journalism. She has penned news and features for titles including Women's Health, Daily Telegraph, Cosmopolitan, The Times, Stylist, The Guardian, Woman & Home, Dazed, The Sun's Fabulous, Yahoo UK and Grazia.
Lauren specialises in covering health and wellness topics—ranging from nutrition and fitness, to health conditions and mental wellbeing. She also runs a weekly newsletter called Well, Actually..., which has been named a Substack Featured Publication.