Breast cancer genetic screening: who is it for, and where does family history fit?
Breast cancer genetic screening starts with a conversation about your relatives rather than a lab test, and it is aimed at women whose family history or ancestry points to an inherited BRCA1 or BRCA2 change, which about 1 in 300 to 500 women overall carries. It is one of the health checks for women where a short family record does most of the early work.
It is common to think about this after a relative's diagnosis, and wanting to know where you stand is a good reason to ask. A harmful change in either gene (called a pathogenic variant in the US, and a faulty gene in many UK services) can be passed down in families and raises the chance of breast and ovarian cancer. Family history is the everyday way of spotting that pattern: a short record of which relatives had which cancers, so you and your care team can decide together whether a test is worth considering.
What is breast cancer genetic screening?
Genetic screening for breast cancer risk looks for inherited changes in the BRCA1 and BRCA2 genes. It does not look for cancer itself; it describes a chance, passed down through a family, of developing breast or ovarian cancer later in life.
That makes it a different check from a mammogram (part of breast screening, as the NHS program is called in the UK), which has its own page and its own schedule.
The words differ by country, though the ground they cover is much the same. In the US the conversation is usually with a genetic counselor; in the UK it runs through a clinical genetics service. The family pattern is often called hereditary breast and ovarian cancer in the US and familial breast cancer in the UK.
Family history is the record; genetic testing is one possible next step from it. A family record can be complete and useful without ever leading to a test.
Why does the evidence point to family history first?
The evidence supports starting with family history because that is where a harmful BRCA change is most likely to be found. In a meta-analysis summarized by the US Preventive Services Task Force (USPSTF, 2019), about 1 in 5 women recruited for a family history of breast or ovarian cancer carried one. Those women were invited into studies because of the cancers in their families, so the figure is not the chance for every woman with one relative who had cancer; and even in those groups, most women did not carry a harmful variant.
Ancestry is the other signal. The USPSTF reports harmful BRCA1/2 variants in 2.1% of Ashkenazi Jewish women overall, several times the figure for women in general. The two countries act on this differently: in the US, ancestry is one of the things a risk assessment asks about, while in the UK the NHS (2026) offers BRCA testing to anyone aged 18 or over with at least one Jewish grandparent.
What a change means for the woman who carries one comes from the National Cancer Institute (2024): lifetime breast cancer risk is over 60% with a harmful BRCA1 or BRCA2 change, compared with about 13% in the general population. Ovarian cancer risk rises too, more with BRCA1 than with BRCA2, from a general-population figure of about 1.1%; the ranges for each gene are in the facts list below.
Taken together, the picture is of a change that is uncommon but matters a good deal for the women who carry it. That is why testing is aimed where a result is most likely to be found and most useful, and why a simple family record comes before any test.
How often to review family history, and the route to a test
A family history is usually taken once and then updated when something changes. Many women find it easiest to raise at a routine visit with their primary care provider (a GP in the UK), rather than waiting for a worry to prompt it.
A record made years ago describes your relatives as they were then, so mentioning a new diagnosis in a close relative at the next routine visit keeps the advice current.
From there the routes differ. In the US, the USPSTF (2019) recommends a short risk assessment tool for women with a relevant family history or ancestry, followed by genetic counseling and testing if the tool comes back positive. In the UK, the NHS (2026) describes a GP asking about your relatives' cancer types and ages at diagnosis and, if risk looks raised, referring you to a specialist breast or genetics clinic.
In either country the first step is a question, not a commitment: taking a family history does not sign you up for a test, and being offered counseling does not oblige you to have one.
What did the studies show, and what did they not show?
The studies show that harmful BRCA changes are more common in women recruited for a family history than in women overall, and that carrying one raises lifetime risk substantially. They do not show what will happen to any one woman: each figure describes a group.
A lifetime risk is the chance added up across a whole life, not the chance in any one year, and the ovarian figures are given as ranges because they are estimates. The two genes carry different numbers, so a result is best read gene by gene.
The ancestry figure is a prevalence, meaning how many women in a group carry a variant. That is a different kind of number from a lifetime risk, which describes what may happen to the women who do carry one. Every figure here is for BRCA1 and BRCA2, so it speaks to those two genes and no further.
The UK pathway described by the NHS is a referral route rather than a study result. What the studies leave open is the personal part: how a result would sit with you, and what you would want to do with it. That is the conversation a genetic counselor (or a clinical genetics service in the UK) is there for.
Family history and genetic testing by life stage
| Stage | Figure | Why | Read more |
|---|---|---|---|
| Childhood | No BRCA test at this stage | Family history at this age is something parents hold: a note of which close relatives had breast, ovarian or bowel cancer is the record later conversations draw on. | Health checks |
| Puberty | UK: BRCA testing from 18 with a Jewish grandparent | The NHS ancestry route opens at 18, so the teenage years are a gentle time to learn the family record, with no test to arrange yet. | Health checks |
| Reproductive years | Once, then update | Breast, ovarian or bowel cancer in close relatives may mean earlier screening or genetic testing. | Health checks |
| Perimenopause | Update after a relative's diagnosis | A new breast or ovarian cancer diagnosis in a close relative is the kind of change that is worth adding to the record at this stage. | Health checks |
| Menopause | No routine BRCA testing without a relevant family history or ancestry (USPSTF grade D) | Reaching menopause does not by itself change who is offered risk assessment; family history and ancestry do. | Health checks |
| Postmenopause | A record worth sharing | Your own history is family history for your relatives; cancer types and ages at diagnosis are the details their GP or primary care provider asks about. | Health checks |
Guidance by country
Facts
Common questions
Do I need breast cancer genetic screening if no one in my family has had cancer?
Probably not as a routine check. The USPSTF (2019) gives this a grade D, meaning it recommends against routine BRCA risk assessment, counseling or testing for women with no relevant family history or ancestry. If a relative is diagnosed later, or you learn something new about your family, the conversation can be reopened at any routine visit.
What should I gather before a family history conversation?
A one-page list is a good place to start: each close relative, the type of cancer they had and roughly how old they were when it was diagnosed. Breast, ovarian and bowel cancers are the ones to note first. A best estimate is fine where the details are hazy, and an older relative can often fill in the gaps.
Does the age a relative was diagnosed make a difference?
It can. In the USPSTF (2019) figures, harmful BRCA1/2 variants were found in 6.0% of women diagnosed with breast cancer before age 40, well above the figure for women in general. A diagnosis at a young age in a relative is worth mentioning to your primary care provider (a GP in the UK), even if the exact age is a guess.
What if I notice a breast change while waiting for a referral?
A new breast lump or any breast change is worth a prompt visit with your primary care provider (a GP in the UK); it does not need to wait for a genetics appointment. A genetic test would not answer it, because testing describes an inherited chance and does not look for cancer. Mentioning your family history at that visit gives the fuller picture.
Can I be tested because of my ancestry, even if no one had cancer?
Ancestry can count on its own. In the US, the USPSTF (2019) lists ancestry alongside personal and family history as a reason for a risk assessment, with genetic counseling following a positive result. In the UK, the NHS ancestry route does not depend on a relative having had cancer, and your GP is the person to ask.
Next steps
If this is on your mind, a short family record is something you can bring to your next routine visit with your primary care provider (your GP in the UK). If the pattern looks raised, you can ask whether a risk tool, a genetic counselor or, in the UK, a referral to a specialist breast or genetics clinic suits you. Some women choose testing, some choose closer screening, and some decide neither is needed right now. You can weigh your family, your values and your care team's advice and decide what fits you, because this is not one size fits all.
See a doctor promptly if you have
- a new breast lump or any breast change
- any bleeding 12 months or more after your last period
Sources
The guidelines and studies this page draws on.
- BRCA-Related Cancer: Risk Assessment, Genetic Counseling, and Genetic Testing (final recommendation), US Preventive Services Task Force (2019)
- BRCA Gene Changes: Cancer Risk and Genetic Testing, National Cancer Institute (2024)
- Breast cancer: causes, NHS (2026)