Why do I need to perform BRCA testing early?

IN THIS ARTICLE

Importance of early testing

The identification of BRCA1/2 and other mutations, the availability of genomic testing, and the development of therapies that target some of these mutations has dramatically changed the evaluation and management of breast cancer.

Breast cancer is the most common type of cancer among women and has an 85% ≥5-year survival rate.*1,2

Females in the general population born after 1960, have a 1 in 7 or 15% risk of developing breast cancer in their lifetime.3

In patients with a germline BRCA1 or BRCA2 mutation, this risk rises to around 50% by age 70, with cumulative risk rising up to ~85%.4-7

Historically, BRCA testing was used mainly as a means to assess an individual’s risk of recurrence, their risk of developing other BRCA-related cancers, the likelihood of the mutation being passed onto relatives, and their own hereditary risk. Now, germline BRCA tests can be used to inform treatment decisions, by tailoring treatments based on the presence or absence of different biomarkers.6,7

Historical and Current use of BRCA Testing
Historical and Current use of BRCA Testing

Germline testing is important to understand a patient’s:8-10

Predisposition:8,9

  • Patients with a germline BRCA mutation have an increased risk of developing cancers such as breast cancer, ovarian cancer, pancreatic cancer, gastrointestinal cancers, melanoma and prostate cancer8,9
  • Patients with a germline BRCA mutation can pass this on to their children7

Treatment options:10

  • Patients with a germline BRCA mutation may have better responses to some treatments with more targeted approaches8
  • Identifying patients with a germline BRCA mutation can influence patient management, specifically related to surgical interventions that may be well-suited to their needs10

Monitoring needs:8,10

  • Identifying patients with a germline BRCA mutation can influence patient management, and point towards high-risk screening and risk reduction methods where necessary8,10

There are several reasons to perform early BRCA testing including:8

  • To identify a potential cause of cancer in an individual
  • To provide an accurate cancer risk assessment and individualised screening/prevention for individuals and their relatives
  • To provide an opportunity for targeted therapy. Performing early testing to know BRCA status means physicians can draw up targeted treatment plans for patients
  • To evaluate surgical options. Performing early testing to understand BRCA status means physicians can evaluate a patient’s options for prophylactic surgery

Test routinely to inform treatment decisions
Test routinely to inform treatment decisions

Test routinely to inform treatment decisions

Testing is important to help inform treatment decisions for breast cancer patients. Guidelines recommend germline BRCA testing to help inform treatment options.6,10

ABC 4/ESMO guidelines state genetic testing should be considered as early as possible in the advanced breast cancer (ABC) setting.11

In the ABC setting, results from genetic testing may have therapeutic implications and should therefore be considered as early as possible.
Genes to be tested for depend on personal and family history; however, at present, only germline mutations in BRCA1/2 have proven clinical utility and therapeautic impact.
Testing for other additional moderate to high penetrance genes may be considered if deemed appropriate by the geneticist.

The American College of Breast Surgeons guidelines suggest that identifying a mutation early can potentially impact treatment recommendations.10

For patients with newly diagnosed breast cancer, identification of a mutation may impact local treatment recommendations (surgery and potentially radiation) and systemic therapy.10

Test routinely to evaluate hereditary risk
Test routinely to evaluate hereditary risk

Test routinely to evaluate hereditary risk

The presence of a germline BRCA mutation increases the risk of development of breast cancer as well as several other common cancers, including ovarian, prostate and pancreatic.7,12

There is a 50% chance of a child inheriting a BRCA mutation from a mother or father carrying a harmful mutation. Identifying a germline BRCA mutation in a patient diagnosed with breast cancer can help to identify any family members who would benefit from germline mutation testing, as they may be at a higher risk of developing the disease.12

Eligibility for testing is based on the presence of factors understood to be associated with an increased likelihood of harbouring a germline BRCA mutation but priority is still largely given to patients with a hereditary risk.6,12

ABC, advanced breast cancer; BRCA, breast cancer gene, ESMO, European Society for Medical Oncology; gBRCA, germline BRCA.

References:

  1. Cancer Research UK. Breast cancer survival statistics. Available at: https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/breast-cancer/survival#heading-Zero [Accessed February 2021].
  2. Breast Cancer Research Foundation. Breast cancer statistics and resources. Available at: https://www.bcrf.org/breast-cancer-statistics-and-resources#:~:text=Breast%20cancer%20is%20the%20most%20common%20cancer%20in%20women%20overall,140%20of%20184%20countries%20worldwide. [Accessed February 2021]
  3. Cancer Research UK. Breast cancer risk. Available at: https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/breast-cancer/risk-factors#heading-Zero (Tab Lifetime risk of breast cancer) [Accessed February 2021].
  4. Kuchenbaecker KB et al. JAMA. 2017; 317: 2402-2416.
  5. Rebbeck TR et al. JAMA. 2015: 313(13); 1347-1361.
  6. Hoogerbrugge N and Jongmans MC. Eur J Hum Genet. 2016; 24: S19-S26.
  7. Pal et al. Cancer Control. 2012; 19: 255-66.
  8. Larsen MJ et al. Breast Cancer (Auckl). 2014: 8; 145-155.
  9. Miller-Samuel S et al. Semin Oncol. 2011; 38: 469-480.
  10. Manahan ER et al. Ann Surg Oncol. 2019; 26: 3025-3031.
  11. Cardoso F et al. Ann Oncol. 2018: 29; 1634-1657.
  12. National Cancer Institute. BRCA1 and BRCA2: Cancer Risk and Genetic Testing. Available at: https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet [Accessed February 2021].
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