What are breast cancer susceptibility genes?

We all have two copies of every gene in our body, inherited from each of our parents. Genes have different functions and instruct our cells to do different things.

Breast cancer susceptibility genes are a group of genes that protect the body from developing a breast cancer, usually through correcting DNA mistakes and repairing DNA copies.

If there’s a pathogenic change in one of these genes, it means they won’t be able to function properly. With a gene not working properly, some of that protection against cancer is lost.

Over time, DNA mistakes can accumulate which puts someone with a change in one of these genes at risk of developing breast and other related cancers over their lifetime.

Read the genomics toolkit which covers breast cancer.

Below is more information about individual genes and their associated risks if there is a pathogenic change in them.

BRCA1 and BRCA2

BRCA1 and BRCA2 are genes involved in DNA repair. Constitutional (germline) pathogenic variants in these genes are associated with hereditary breast and ovarian cancer (HBOC), as well as other cancers.

For more information on BRCA1 and BRCA2, please refer to GeNotes: Genomic notes for clinicians.

Estimated lifetime cancer risk for carriers of germline pathogenic variants in BRCA1 and BRCA2:

A table showing the estimated lifetime cancer risk for carriers of germline pathogenic variants in BRCA1 and BRCA2.

Kuchenbaecker KB, Hopper JL, Barnes DR et al. ‘Risks of Breast, Ovarian, and Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers‘. JAMA 2017: volume 317, issue 23, pages 2402 2416. doi :10.1001/jama.2017.7112

 

 

 

BRCA1

 

Cumulative cancer risk per age bracket for a female carrying a BRCA1germline pathogenic variant (UKCGG)

Age (years) Breast Cancer Ovarian Cancer
21 - 30 4% -
31 - 40 24% 2%
41 - 50 43% 8%
51 - 60 56% 20%
61 - 70 66% 41%
71 - 80 72% 44%

 

Population lifetime risk of breast cancer: 13% (According to Cancer Research UK, 2023.

For more detail, please see UKCGG: BRCA1Germline Pathogenic Variant Carriers Management Guidelines for Healthcare Professionals.

 

 

Other Cancers: Risk for those with PV in BRCA1

Cancer Type BRCA1 Population
Male Breast 0.4% Rare
Prostate 17% 12%
Pancreatic 3% 2%

 

 

Cumulative risk for a contralateral breast cancer (time since first breast cancer): ~2-2.5%/year

Age Percentage
<5 years 13%
>5-10 years 23%
>10-15 years 32%
>15-20 years 40%
>20-45 years 53%

 

 

BRCA2

Cumulative cancer risk per age bracket for a female carrying a BRCA2 germline pathogenic variant (UKCGG)

Age (years) Breast Cancer Ovarian Cancer
21 - 30 4% -
31 - 40 13% <0.5%
41 - 50 35% 1-2%
51 - 60 53% 7%
61 - 70 61% 15%
71 - 80 69% 17%

 

Population lifetime risk of breast cancer: 13%, according to Cancer Research UK, 2023

For more detail, please see UKCGG: BRCA2Germline Pathogenic Variant Carriers Management Guidelines for Healthcare Professionals.

 

Cumulative Risk for Contralateral Breast Cancer (Time Since First Breast Cancer)

Time Since First Breast Cancer Percentage
<5 years 8%
>5-10 years 16%
>10-15 years 21%
>15-20 years 26%
>20-45 years 65%

 

Other Cancers: Risk for those with PV in BRCA2

Cancer Type BRCA2 Population
Male Breast 4% Rare
Prostate 41% 18%
Pancreatic male 4-5% 2%
Pancreatic female 2% 2%

 

PALB2

PALB2 is a gene involved in homologous recombination repair. Heterozygous constitutional (germline) pathogenic variants in PALB2 are associated with increased cancer risks, predominantly breast cancer.

Learn more about PALB2 by visiting GeNotes: Genomic notes for clinicians.

Estimated lifetime cancer risk for carriers of germline pathogenic variants in PALB2:

 

A table showing the estimated lifetime cancer risk for carriers of germline pathogenic variants in PALB2. 

 

Yang, Xin et al. “Cancer Risks Associated With Germline PALB2 Pathogenic Variants: An International Study of 524 Families.” Journal of clinical oncology: official journal of the American Society of Clinical Oncology vol. 38,7 (2020): 674 685. doi:10.1200/JCO.19.01907

 

Genomics toolkit PALB2 chromosome 16
Nepomuceno, T.C.; De Gregoriis , G.; De Oliveira, F.M.B.; Suarez Kurtz, G.; Monteiro, A.N.; Carvalho, M.A. The Role of PALB2 in the DNA Damage Response and Cancer Predisposition. Int. J. Mol. Sci. 2017 18 , 1886. https://doi.org/10.3390/ijms18091886

“On the basis of the combined data, the estimated risks to age 80 years were 53% (95% CI, 44% to 63%) for female breast cancer, 5% (95% CI, 2% to 10%) for ovarian cancer, 2% 3% (95% CI females, 1% to 4%; 95% CI males, 2% to 5%) for pancreatic cancer, and 1% (95% CI, 0.2% to 5%) for male breast cancer.”

ATM

People with an inherited mutation in ATM have increased risk for certain cancers.

Learn more about the ATM mutation by visiting the Facing Our Risk website.

Estimated lifetime cancer risk for carriers of germline pathogenic variants in ATM:

A table showing the estimated lifetime cancer risk for carriers of germline pathogenic variants in ATM. 
 

"Ataxia Telangiesctasia Mutated." The ATM gene is located on chromosome 11. ATM helps to control cell growth and repair damaged DNA.

CHEK2

People with an inherited mutation in CHEK2 have increased risk for certain cancers.

Learn more about CHEK2 by visiting the Facing Our Risk website.

Estimated lifetime cancer risk for carriers of germline pathogenic variants in CHEK2:

A graph showing the estimated lifetime cancer risk for carriers of germline pathogenic variants in CHEK2. 

Male CHEK2 pathogenic variant carriers have an increased risk of male breast cancer (approx 1% based on limited data), and could be linked to an increased risk of other cancers.

 

CHEK2 stands for Checkpoint Kinase 2. The gene is located on chromosome 22. CHEK2 helps control how cells divide. Increased risk of breast cancer: 20-40%.

An image showing the location of CHEK22 on chromosome 22.
 

CHEK2 Gene - GeneCards | CHK2 Protein | CHK2 Antibody

RAD51C and RAD51D

People with an inherited mutation in RAD51C and RAD51D have increased risk for certain cancers. 

Learn more about RAD51C and RAD51D by visiting the Facing our Risk website:

Estimated lifetime cancer risk for carriers of germline pathogenic variants in RAD51C and RAD51D:

A table showing the estimated lifetime cancer risk for carriers of germline pathogenic variants in RAD51C and RAD51D.

 

Both are located on chromosome 17, involved in DNA repair (Homologous Recombination).

RAD51C and RAD51D gene card
 

Increased risk of breast cancer: 20-40%. Women with a RAD51C or RAD51D alteration are more likely to develop ‘Triple Negative’ Breast Cancers.

 

Management recommendations for a pathogenic variant

BRCA1

For detail, please see UKCGG: BRCA1Germline Pathogenic Variant Carriers Management Guidelines for Healthcare Professionals.

 

BRCA2

For detail, please see UKCGG: BRCA2Germline Pathogenic Variant Carriers Management Guidelines for Healthcare Professionals.

 

RAD51C and RAD51D

Surveillance:

  • Breast: Should be based on individualised risk assessment using tools such as CanRisk *, and in accordance with NICE guidelines on familial breast cancer (CG164).
    • Moderate risk surveillance (lifetime risk of 17-29%): annual mammograms 40 49 years then NHSBSP
    • High risk surveillance (lifetime risk of ≥30% but <40%): annual mammograms 40-59 years then NHSBSP
    • Very high risk surveillance (lifetime risk of ≥40% and 10 year risk of 8% 25 29 yrs , 30 39 years or 12% 40 49 years ): refer to VHR breast screening programme
  • Tubo-Ovarian: Not currently recommended. No evidence based screening programme. Should be offered only as part of an ethically approved research study

 

Risk reducing surgery:

  • Tubo-Ovarian: For RAD51C and RAD51D carriers with ≥5% lifetime risk, RRSO should be considered from 50 years. It can be considered in carriers younger than 50 years following individualised risk assessment*, including assessment of menopausal symptoms and shared decision making.
  • Risk reducing early salpingectomy with delayed oophorectomy should currently only be offered in the context of a research study
  • Breast: Consider discussion of risk reducing mastectomy if lifetime risk ≥30%, in conjunction with an individualised risk assessment* and appropriate counselling.

*Individualised breast, contralateral breast and ovarian cancer risk estimates which incorporate germline PV carrier status, personal risk factors and where relevant breast cancer receptor status, polygenic risk score and breast density, are available at https://canrisk.org/ (Lee et al., 2021) SOURCE: www.ukcgg.org

For more detail, view the UKCGG leaflets and guidelines.

 

UK consensus recommendations for clinical management of cancer risk for women with germline pathogenic variants in cancer predisposition genes: RAD51C, RAD51D, BRIP1 and PALB2

Breast: Should be based on individualised risk assessment using tools such as CanRisk*, and in accordance with NICE guidelines on familial breast cancer (CG164).

  • Moderate risk surveillance (lifetime risk of 17-29%): annual mammograms 40-49 years then NHSBSP
  • High risk surveillance (lifetime risk of ≥30% but <40%): annual mammograms 40-59 years then NHSBSP
  • Very high risk surveillance (lifetime risk of ≥40% and 10 year risk of 8% 25-29 yrs , 30-39 years or 12% 40-49 years ): refer to VHR breast screening programme

Hanson, H., Kulkarni, A., Loong, L., Kavanaugh, G. et al. “UK consensus recommendations of cancer risk for women with germline pathogenic variants in cancer predisposition genes: RAD51C, RAD51D, BRIP1 and PALB2 .” Journal of Medical Genetics, BMJ. 2022; 0: 1 13. doi : 10.1136/jmg 2022 108898

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Reading List

  • Calzone, K. A., Kirk, M., Tonkin, E., Badzek , L., Benjamin, C., & Middleton, A. (2018). The global landscape of nursing and genomics. Journal of Nursing Scholarship, 50(3), 249 256 https://doi.org/10.1111/jnu.12380
  • Coulson J. (2022). ‘Understanding the role of genomics in nursing practice.’ Nursing standard (Royal College of Nursing (Great Britain), 10.7748/ns.2022.e12053. Advance online publication. https://doi.org/10.7748/ns.2022.e12053
  • Cuthill, V. (2023), ‘Demystifying Genomics in Cancer Care’, Macmillan Cancer Support. Available at: Demystifying genomics in cancer care | Macmillan Cancer Support
  • Hanson, H., Kulkarni, A., Loong, L., Kavanaugh, G. et al. (2022) ‘UK consensus recommendations of cancer risk for women with germline pathogenic variants in cancer predisposition genes: RAD51C, RAD51D, BRIP1 and PALB2.’ Journal of Medical Genetics, BMJ. 0: 1 13. doi: https://doi.org/10.1136/jmg-2022-108898
  • Launer , J. (2021) ’Effective Clinical Conversations: The Art of Curiosity’ Postgrad Med J, 97, pp 339 340. DOI: Effective clinical conversations: the art of curiosity (bmj.com)
  • NHS England, (2022) ‘Accelerating genomic medicine in the NHS’, NHS England. Available at: NHS England » Accelerating genomic medicine in the NHS
  • Patch, C. & Middleton, A. (2018) ‘Genetic counselling in the era of genomic medicine’, British Medical Bulletin, 126(1), 27 36. DOI: https://doi.org/10.1093/bmb/ldy008
  • Pichini , A & Bishop, M. (2022) ‘A nationally agreed cross professional competency framework to facilitate genomic testing’ Genetics in Medicine. 24(8), 1743 1752. DOI: https://doi.org/10.1016/j.gim.2022.04.023
  • Roberts, E., Howell, S., Evans, G. (2023) ‘Polygenic risk scores and breast cancer risk prediction.’ The Breast, 67, 71-77 DOI: https://doi.org/10.1016/j.breast.2023.01.003
  • Yang, Xin et al. “Cancer Risks Associated With Germline PALB2 Pathogenic Variants: An International Study of 524 Families.” Journal of clinical oncology: official journal of the American Society of Clinical Oncology vol. 38,7 (2020): 674 685. doi:10.1200/JCO.19.01907