Breast Care A-Z · Concept · BRCA

BRCA

also: BRCA1, BRCA2, BRCA gene, BRCA mutation, BRCA testing, BRCA gene testing · pronounced BRACK-uh, or B-R-C-A

BRCA1 and BRCA2 are genes that help repair DNA; an inherited fault in either one significantly raises the lifetime risk of breast and ovarian cancer. You may be considering genetic testing because of a family history, or working out what a positive result means for screening and risk-reducing options.

Quick answers

If I test positive, do I have to have surgery?

No. Surgery is one option among three (the others being surveillance and chemoprevention). Many BRCA carriers choose surveillance for years before considering surgery, or never proceed to surgery. The decision is yours and is rarely urgent.

How accurate is the test?

Modern BRCA testing for known mutations is highly accurate. The interpretation is more nuanced when a variant of uncertain significance (VUS) is identified — a change in the gene whose effect is not clearly known. The genetics team explains this carefully if it comes up.

Will my insurance cover testing?

NHS testing is available to people meeting family-history criteria, free of charge. 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.

BREASTORY ENCYCLOPEDIA · PLATE XXXVI GENETICS · HEREDITARY CANCER SYNDROMES BRCA gene mutation BRCA1 · BRCA2 · hereditary breast and ovarian cancer syndrome tumour suppressor gene mutations conferring high lifetime risk of breast and ovarian malignancy i FIG 01 DNA Double Helix · Gene Loci · Mutation Pathway iii — mutation site Chromosome 17 — BRCA1 i — BRCA1 locus (17q21) Chromosome 13 — BRCA2 ii — BRCA2 locus (13q12) DNA damage double-strand break BRCA protein tumour suppressor DNA repair homologous recombination iv — DNA repair failure when BRCA mutated v — tumour suppressor function lost → accumulating somatic mutations → malignancy BRCA PROTEIN FUNCTION Normal pathway: DNA double-strand break → BRCA1/2 protein → homologous recombination repair → intact genome Mutant pathway: Break → no functional BRCA protein → error-prone repair → accumulating mutations → malignancy BRCA mutations follow autosomal dominant inheritance TESTING PATHWAY Clinical criteria met family hx Genetic counselling pre-test BRCA testing blood/saliva 4–8 weeks NICE NG151 criteria: ≥10% probability via Manchester / BOADICEA scoring Cascade testing offered to relatives i FIG 02 BRCA1 vs BRCA2 — Comparative Gene Characteristics BRCA1 BRCA2 Chromosome 17q21 13q12 Gene size 81 exons, ~81 kb 27 exons, ~70 kb Breast cancer risk ~72% lifetime ~69% lifetime Ovarian cancer risk ~44% lifetime ~17% lifetime Pancreatic risk Slightly elevated Notably elevated Prostate risk Slight increase Elevated (~20–30%) Male breast cancer Slight increase ~6% lifetime Tumour subtype Often triple-negative Often hormone receptor+ Age of onset Typically younger (<50) Slightly older presentation Prevalence ~1 in 500 general population ~1 in 400 general population i FIG 03 BRCA Carrier vs General Population Cancer Risks Cancer type General population BRCA carrier Female breast ~12% lifetime ~70% lifetime Ovarian ~1.3% lifetime ~17–44% lifetime Contralateral breast ~6% after first cancer ~30–50% Pancreatic ~1–2% lifetime ~3–4% (higher in BRCA2) Male breast ~0.1% lifetime ~6% lifetime (BRCA2) Prostate ~12% lifetime ~20–30% (BRCA2) Melanoma ~2% lifetime Slight increase Colorectal ~5% lifetime No significant increase Overall mortality Background rate Significantly elevated i FIG 04 BRCA Clinical Pathway Family hx identified ≥2 affected Risk criteria assessed BOADICEA Genetics referral NHS clinic BRCA test performed blood/saliva Result + counselling post-test Risk-mgmt plan MDT Risk management options: enhanced surveillance / chemoprevention (tamoxifen/raloxifene) / risk-reducing surgery BRCA1/2 carriers eligible for annual MRI from age 30; mammography from 40 (NICE NG151) Risk-reducing mastectomy reduces breast cancer risk by ~95%; salpingo-oophorectomy reduces ovarian risk ~80% PARP inhibitors (olaparib, niraparib) now standard-of-care treatment for BRCA-mutated cancers Cascade testing: all first-degree relatives offered predictive testing upon positive probands result i FIG 05 Related Genes — Hereditary Breast Cancer Syndromes BRCA1 HIGH RISK 17q21 · Tumour suppressor ~72% breast, ~44% ovarian PARP inhibitor sensitive BRCA2 HIGH RISK 13q12 · Tumour suppressor ~69% breast, ~17% ovarian Also prostate, pancreatic PALB2 HIGH RISK 16p12 · BRCA2 partner ~35–58% lifetime breast risk Included in panel testing TP53 HIGH RISK 17p13 · Li–Fraumeni syndrome >80% lifetime breast risk Childhood cancers also CHEK2 MODERATE RISK 22q12 · Cell cycle checkpoint ~25–30% lifetime breast risk Also colorectal, prostate ATM MODERATE RISK 11q22 · DNA damage response ~25% lifetime breast risk Ataxia-telangiectasia carrier i FIG 06 Key Statistics 1 in 400 carry a BRCA mutation in general population [1] Antoniou 2003 ~72% lifetime breast cancer risk BRCA1 carriers [2] Chen 2007 ~44% lifetime ovarian cancer risk BRCA1 carriers [2] Chen 2007 10× higher breast cancer risk vs general population [3] NICE NG151 i FIG 07 References 1. Antoniou A et al. Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations. Am J Hum Genet. 2003;72:1117. 2. Chen S, Parmigiani G. Meta-analysis of BRCA1 and BRCA2 penetrance. J Clin Oncol. 2007;25:1329–1333. 3. NICE NG151. Familial breast cancer: classification, care and managing breast cancer and related risks. 2023. 4. NICE DG27. BRCA1 and BRCA2 testing guidance. 2022. 5. Kuchenbaecker KB et al. Risks of breast, ovarian, and contralateral breast cancer for BRCA1/2 mutation carriers. JAMA. 2017;317:2402–2416. 6. Robson M et al. Olaparib for metastatic breast cancer in patients with a germline BRCA mutation. NEJM. 2017;377:523. 7. Mavaddat N et al. Polygenic risk scores for prediction of breast cancer and breast cancer subtypes. Am J Hum Genet. 2019;104:21. All content for educational purposes only. Genetic testing should be performed and interpreted by a qualified clinical geneticist. Risk figures are population averages; individual risk is modified by other variants, reproductive history, and lifestyle factors. Clinically authored by Dr Fiona Tsang-Wright , FRCS (Gen Surg) GMC 4549831 · ORCID 0000-0003-4801-026X
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Definition
BRCA1 and BRCA2 are genes that everyone has — they normally help repair damaged DNA in cells. Inherited mutations in either gene meaningfully raise lifetime breast, ovarian, and (in BRCA2) prostate and pancreatic cancer risk, and trigger structured surveillance and risk-reducing options under UK NICE familial cancer guidance.
≈ 72% BRCA1 cumulative breast cancer risk by age 80 1
≈ 69% BRCA2 cumulative breast cancer risk by age 80 1
≈ 90% Risk reduction from bilateral prophylactic mastectomy 4

Common questions The questions patients ask first

If I test positive, do I have to have surgery?
No. Surgery is one option among three (the others being surveillance and chemoprevention)2. Many BRCA carriers choose surveillance for years before considering surgery, or never proceed to surgery. The decision is yours and is rarely urgent.
How accurate is the test?
Modern BRCA testing for known mutations is highly accurate. The interpretation is more nuanced when a variant of uncertain significance (VUS) is identified — a change in the gene whose effect is not clearly known. The genetics team explains this carefully if it comes up.
Will my insurance cover testing?
NHS testing is available to people meeting family-history criteria2, free of charge. 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 if I'm a man with a BRCA mutation?
Men with BRCA mutations have a small but raised risk of male breast cancer1 (BRCA2 more than BRCA1) and a raised risk of prostate cancer. Surveillance is offered for both. Risk-reducing mastectomy is rarely considered for men because the absolute breast cancer risk, while raised, remains relatively low. Children of either sex have the same 50% chance of inheriting the mutation.

BRCA1 and BRCA2 are two genes that, when working normally, help repair DNA damage in cells; inherited mutations in either gene substantially increase the lifetime risk of breast and ovarian cancer and are the most common high-risk genetic cause of these cancers in the UK.

A BRCA mutation is a change in one of these two genes that interferes with their normal function. People who inherit a BRCA mutation have a significantly higher lifetime risk of breast and ovarian cancer than the general population. Knowing your BRCA status — through genetic testing — can change decisions about screening, chemoprevention, and (in some cases) risk-reducing surgery.

Orientation Why you might be reading about this

You may have a family history of breast or ovarian cancer and be considering genetic testing, or you may have already tested positive for a BRCA mutation and be working out what that means for the next decade of your life. Either way, the BRCA conversation is one of the more consequential in private breast practice. This page explains what BRCA is, what testing involves, and what the practical implications are.

Related terms: Mastectomy · Sentinel lymph node biopsy · Mammogram · DCIS · Risk-reducing mastectomy

Definition What BRCA1 and BRCA2 do

BRCA1 and BRCA2 are tumour suppressor genes — genes that, when functioning normally, help cells repair DNA damage and prevent uncontrolled cell division. Everyone has two copies of each gene (one inherited from each parent).

When a person inherits a mutation in BRCA1 or BRCA2 — a change in the gene that stops it working properly — the cells of the body have less effective DNA repair, and over time the chance of developing certain cancers rises. The mutations are inherited in an autosomal dominant pattern, which means that:

  • A person who carries a BRCA mutation has a 50% chance of passing it to each child1.
  • Both men and women can carry and pass on BRCA mutations.

Risk numbers What having a BRCA mutation means in numbers

The lifetime risk figures vary slightly between studies, but the patient-facing figures used in UK practice are approximately:

Breast cancer risk by age 80 Ovarian cancer risk by age 80
General population (UK) ~12% ~2%
BRCA1 carrier ~72% (65–79%) ~44% (36–53%)
BRCA2 carrier ~69% (61–77%) ~17% (11–25%)

BRCA mutations also raise the lifetime risk of other cancers — particularly prostate cancer and pancreatic cancer in men with BRCA mutations — and a small additional risk of melanoma. The breast and ovarian risks are by far the largest.

Testing Testing for BRCA mutations

Genetic testing for BRCA is widely available on the NHS2 and privately, with an established pathway:

  1. Family-history risk assessment — usually with a clinical geneticist or family-history clinic. The risk is estimated using tools such as Tyrer-Cuzick or BOADICEA, taking into account who in the family has had breast or ovarian cancer, at what ages, and other factors.
  2. Genetic counselling — a structured conversation about what testing involves, what the possible results mean, and the implications for the patient and their relatives. Genetic testing is rarely done without counselling first.
  3. The test itself — a blood sample, sent for DNA analysis. Results take several weeks. Modern panels usually test for mutations in BRCA1, BRCA2, and several other related genes (PALB25, CHEK2, ATM, TP53) at the same time, because some of those have similar risk implications.
  4. Result and follow-up — a positive result triggers a discussion of surveillance, chemoprevention, and (if appropriate) risk-reducing surgery. A negative result in someone with a known family mutation is reassuring; a negative result where no family mutation has been identified is less informative.

Positive result What changes with a positive result

Knowing you carry a BRCA mutation does not automatically change the day-to-day; what it changes is the range of choices available to you over the years that follow:

Enhanced surveillance

For most BRCA carriers, annual breast MRI from age 30 (sometimes from 25) is recommended, often with annual mammography added from age 402. The aim is to detect any cancer that develops at the earliest possible stage. Surveillance does not prevent cancer; it catches it early.

Chemoprevention

Tamoxifen (typically for 5 years, in pre-menopausal patients4) and anastrozole or exemestane (in post-menopausal patients) reduce breast cancer incidence by around 30–50% in high-risk patients6. They have side effects — hot flushes, joint aches, a small thrombosis risk with tamoxifen — and the decision is individual.

Risk-reducing surgery

Bilateral risk-reducing mastectomy reduces breast cancer risk by approximately 90–95% in BRCA1 and BRCA2 carriers378. It is a major operation and a personal decision; surveillance and chemoprevention are reasonable alternatives. See risk-reducing mastectomy.

Risk-reducing salpingo-oophorectomy — removal of the fallopian tubes and ovaries — is recommended from age 35{nd}40 for BRCA1 carriers and age 40{nd}45 for BRCA2 carriers, once the patient has completed their family, performed by a gynaecological surgeon27. It reduces ovarian cancer risk substantially and also reduces breast cancer risk7.

Information for relatives

A positive BRCA result has implications for first-degree and second-degree relatives — parents, siblings, children, aunts and uncles. The clinical genetics team works with the patient on how to share the result and arrange testing for relatives who want it.

Negative result What changes with a negative result

A negative test in someone whose family has a known BRCA mutation is a true negative — the patient is not at the elevated risk associated with the mutation, and the family-history considerations no longer apply.

A negative test in someone whose family does not have an identified mutation is less definitive — there may still be a family-history risk that is not driven by a BRCA mutation, and surveillance may still be recommended on the basis of the family pattern even with a negative test.

At consultation What to discuss at consultation

For patients considering BRCA testing, conversations are usually with a clinical geneticist or a family-history clinic rather than a surgeon. For patients with a known BRCA result who are considering surgical risk reduction, the conversation moves to a surgical consultation, typically covering:

  • The risk-reduction figures specific to your gene and your age.
  • The alternatives — surveillance, chemoprevention — and how they compare to surgery.
  • The operation itself: nipple-sparing or skin-sparing technique, reconstruction options, recovery, and outcomes.
  • Timing — most patients consider this decision over months, not weeks.

For background, see risk-reducing mastectomy and contralateral risk-reducing mastectomy for patients with a previous breast cancer.

Resources Further reading

Sources & guidance

Every figure on this page is anchored to a published source. Tap a number in the text or below to jump to the reference.

  1. cohort Kuchenbaecker KB, Hopper JL, Barnes DR, et al. Risks of Breast, Ovarian, and Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers. JAMA. 2017 ;317(23):2402-2416 doi:10.1001/jama.2017.7112 Cited for: Lifetime breast cancer risk in BRCA1 (~72%) and BRCA2 (~69%) carriers; ovarian cancer risk; contralateral risk.
  2. guidance National Institute for Health and Care Excellence (NICE). Familial breast cancer: classification, care and managing breast cancer and related risks in people with a family history. NICE clinical guideline CG164. London: NICE. 2019 https://www.nice.org.uk/guidance/cg164 Cited for: Risk thresholds (population/moderate/high), surveillance schedules, genetic testing criteria, chemoprevention guidance.
  3. cohort Hartmann LC, Sellers TA, Schaid DJ, et al. Efficacy of bilateral prophylactic mastectomy in women with a family history of breast cancer. New England Journal of Medicine. 1999 ;340(2):77-84 doi:10.1056/NEJM199901143400201 Cited for: ~90% breast cancer risk reduction from bilateral prophylactic mastectomy in high-risk women.
  4. meta analysis Early Breast Cancer Trialists' Collaborative Group (EBCTCG). Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials. The Lancet. 2011 ;378(9793):771-784 doi:10.1016/S0140-6736(11)60993-8 Cited for: Magnitude and durability of tamoxifen benefit in ER-positive breast cancer; ~50% reduction in recurrence over 5 years.
  5. cohort Antoniou AC, Casadei S, Heikkinen T, et al. Breast-cancer risk in families with mutations in PALB2. New England Journal of Medicine. 2014 ;371(6):497-506 doi:10.1056/NEJMoa1400382 Cited for: PALB2 lifetime breast cancer risk (~33-58%); landmark cohort establishing PALB2 as a high-penetrance gene.
  6. rct Cuzick J, Sestak I, Forbes JF, et al. Anastrozole for prevention of breast cancer in high-risk postmenopausal women (IBIS-II): an international, double-blind, randomised placebo-controlled trial. Lancet. 2014 ;383(9922):1041-1048 doi:10.1016/S0140-6736(13)62292-8 Cited for: IBIS-II: anastrozole reduces breast cancer incidence in high-risk postmenopausal women — chemoprevention evidence.
  7. cohort Domchek SM, Friebel TM, Singer CF, et al. Association of risk-reducing surgery in BRCA1 or BRCA2 mutation carriers with cancer risk and mortality. JAMA. 2010 ;304(9):967-975 doi:10.1001/jama.2010.1237 Cited for: Risk-reducing mastectomy and salpingo-oophorectomy in BRCA carriers: cancer-incidence reduction and all-cause mortality benefit.
  8. guideline National Institute for Health and Care Excellence. Early and locally advanced breast cancer: diagnosis and management (NG101). NICE. 2018 ;Last updated 2024 https://www.nice.org.uk/guidance/ng101 Cited for: UK guideline for surgical management including risk-reducing operations and reconstruction pathway.