A common question in primary care and at family gatherings: “My mother / sister / aunt had breast cancer — what does that mean for me?”

The answer depends on the specific family pattern rather than on any single relative’s diagnosis. Most family history of breast cancer does not raise an individual’s risk meaningfully above the population baseline. Some patterns do, sometimes substantially. The point of formal assessment is to know which group you are in — and what, if anything, to do about it.

This piece walks through the practical version of that assessment: what counts as a significant family history, who to talk to first, what genetic testing involves, and what choices become available for patients in the high-risk group.

What counts as significant

Not every family history needs assessment. The patterns that do warrant a conversation with a GP and possibly onward referral:

A first-degree relative (mother, sister, daughter) with breast cancer under 40.
Multiple first-degree relatives with breast cancer at any age.
A relative with bilateral breast cancer (cancer in both breasts).
A male relative with breast cancer — uncommon, and a stronger signal of an inherited cause.
A relative with ovarian cancer at any age — particularly important when combined with breast cancer in the family.
A relative with pancreatic cancer — sometimes part of a BRCA-related family pattern.
Ashkenazi Jewish ancestry — associated with a higher background frequency of certain BRCA mutations.
A known genetic mutation in the family (BRCA1, BRCA2, PALB2, TP53, others).

A single relative diagnosed in their 70s or 80s usually does not constitute a significant family history. The pattern matters more than the count.

For more detail, see the family history glossary entry.

What does not count as significant

Equally worth saying clearly:

A grandmother or great-aunt who had breast cancer in her 70s — this alone does not raise your risk meaningfully.
A relative who had breast cancer that was treated and cured many years ago — relevant to the family pattern, but not a separate concern.
Several relatives with cancers in different organs (lung, colon, etc.) — these do not usually share a genetic basis with breast cancer.
Worry about cancer in general without a specific family pattern — important to share with a GP, but not in itself an indication for genetic testing.

The most useful single thing a patient can do is gather the family history accurately before a GP appointment — who had what cancer, at what age, on which side of the family — rather than working with vague impressions.

The pathway

For patients whose family history meets the threshold above, the pathway typically runs through three stages:

1. GP appointment

The starting point. The GP records the family history, performs an initial risk assessment using a structured tool, and decides whether to refer onward. For most patients with a single concerning feature, the GP will reassure and arrange routine breast screening at the appropriate age. For those whose pattern warrants formal assessment, the GP refers to a family-history clinic or clinical genetics service.

For more on the threshold for referral, see the referral criteria page.

2. Family-history clinic / clinical genetics

This is where the formal assessment happens. The first appointment usually involves:

A detailed family-history interview, with confirmation of relatives’ diagnoses where possible.
A formal risk calculation using validated tools — Tyrer-Cuzick, BOADICEA, or Manchester score. See breast cancer risk assessment.
A discussion of genetic testing — what it can and cannot tell you, and who in the family is the right starting point for testing.
A surveillance plan — what imaging, at what frequency, starting at what age.
A discussion of chemoprevention (tamoxifen or aromatase inhibitors) for moderate-to-high-risk patients.

For high-risk patients, a separate appointment with a breast surgeon to discuss risk-reducing options is the next step, often after time to consider.

3. Genetic testing (where indicated)

Genetic testing is most informative when:

There is already a confirmed family mutation — the patient’s test gives a clear positive or negative.
An affected family member is available to test first — a positive result in an affected relative makes testing of unaffected relatives definitive.
The family pattern strongly suggests an inherited cause, even without an identified mutation.

A typical modern test is a panel test that looks at BRCA1, BRCA2, PALB2, CHEK2, ATM, TP53, and several other relevant genes simultaneously. Results take several weeks. For more on what BRCA results mean, see the BRCA glossary entry.

What changes if you test positive

A positive result for a high-risk gene mutation (BRCA1, BRCA2, PALB2, TP53) opens up three options. None is obligatory; most patients consider all three over time.

Enhanced surveillance

For most BRCA carriers:

Annual breast MRI from age 30 (sometimes 25 for very high risk).
Annual mammography added from age 40.
Clinical examination at intervals.

The aim is to catch any cancer that does develop at the earliest, most curable stage. Surveillance does not prevent cancer — it detects it early.

Chemoprevention

Drugs that reduce the chance of developing breast cancer:

Tamoxifen (5 years, in pre-menopausal patients) reduces breast cancer incidence by approximately 30–50% in high-risk patients.
Aromatase inhibitors (anastrozole, letrozole, exemestane) for post-menopausal patients have a similar protective effect.

Side effects (hot flushes, joint aches, bone-density loss with aromatase inhibitors, small thrombosis risk with tamoxifen) need weighing against the benefit. Chemoprevention is a real option for some moderate- and high-risk patients but is not for everyone.

Risk-reducing surgery

Bilateral risk-reducing mastectomy reduces breast cancer risk by approximately 90–95% in BRCA carriers. It is a major operation performed on healthy breast tissue, and the decision is rarely urgent. See risk-reducing mastectomy and the glossary entry.

For BRCA1, BRCA2, and PALB2 carriers, risk-reducing salpingo-oophorectomy (removal of the fallopian tubes and ovaries) is also recommended in the late 30s for BRCA1 and the early 40s for BRCA2, performed by a gynaecological surgeon. It reduces ovarian cancer risk substantially and is a separate decision from the breast-side surgery.

These options are not exclusive. Many patients have years of surveillance before considering surgery; some start with chemoprevention; some choose surgery in their late 20s or early 30s; some choose surveillance for life and never have surgery. All are reasonable.

What changes if you test negative

A negative test result depends on context:

Negative test in someone whose family has a known mutation — true negative. The patient is at general-population risk and the family-history considerations no longer apply.
Negative test in someone whose family does not have an identified mutation — less definitive. There may still be a family-history risk that is not driven by a BRCA-type mutation. Surveillance may still be recommended on the basis of the family pattern, even with a negative test.

For most patients, a negative test is a meaningful reassurance that does change long-term management. But it is not always the end of the conversation.

What changes if you test for a “variant of uncertain significance”

Genetic tests sometimes return a VUS — a change in a gene whose effect is not clearly known. This can be unsettling to receive, but the practical answer is usually:

Treat the patient as if the VUS were absent, while monitoring for the gene’s classification to be updated as more evidence accumulates over time.
Continue family-history-based surveillance rather than treating the VUS as if it were a confirmed mutation.
Re-contact the genetics service in a few years if the VUS classification has changed.

The genetics team explains this carefully if it comes up.

Common questions

My mother had breast cancer at 65 — should I be tested?

A single first-degree relative diagnosed in their 60s gives a modest increase in risk over the general population, but usually not enough to change routine surveillance, and rarely enough to warrant genetic testing. The standard NHS Breast Screening Programme is appropriate. Risk increases more meaningfully with multiple affected relatives, younger ages at diagnosis, or other features.

What if I’m adopted and don’t know my biological family history?

Adopted patients can still be assessed for risk based on personal factors (breast density, hormonal history, biopsy history). Genetic testing is sometimes offered without family history — particularly if the patient has had an early-onset cancer or specific concerning features. The family-history clinic can advise.

Does it matter which side of the family the cancer is on?

Yes — both sides count, but they are assessed separately. A father with three sisters with breast cancer is a strong family-history signal even though the patient’s mother’s side may be unaffected. Risk-assessment tools take both maternal and paternal patterns into account.

What about my children?

If a high-risk gene mutation is identified, first-degree relatives (parents, siblings, children) have a 50% chance of carrying the same mutation. Testing of relatives — sometimes called cascade testing — is a separate decision for each individual, usually arranged through clinical genetics. Children are not typically tested before adulthood unless there is a specific clinical reason.

Will my insurance cover testing?

NHS testing is free for patients meeting the family-history criteria. Private testing is available for self-pay or via some private medical insurers; insurer policies vary, and it is worth confirming before booking. Once a high-risk result is identified, risk-reducing surgery is usually covered by major UK insurers as part of cancer-prevention treatment.

What to do next

If you are unsure whether your family history warrants assessment:

Start with your GP. They will record the family history accurately and decide on the appropriate next step. If onward referral is indicated, the route is via NHS family-history clinic or clinical genetics service.
Bring as much detail as you can — names, ages at diagnosis, types of cancer, relationships. The most useful 30 minutes you can spend before the GP appointment is making sure the family history is correct.

For private specialist consultation — particularly for risk-reducing surgery once genetic status is known — contact Sarah or Nadiya, Dr Tsang-Wright’s PAs, at [email protected] or 07785 274 744.