Genetics-based test for breast cancer risk

The challenge

Worldwide, breast cancer is the most common cancer in women, with over 2 million new cases each year.[1] In Europe, mammographic screening of women aged 50-74 diagnoses approximately 58% of all breast cancer cases.[2] Mammography is cost-effective and reduces the risk of dying from breast cancer by 20-40%.[3][4][5]

Women’s risk of breast cancer depends on many environmental and genetic factors.[6] Yet, in Europe, only age-based selection is used for mammographic screening. The lack of risk-based selection for screening affects outcomes for patients.

At risk women under 50 are not commonly screened, even though this group accounts for more than 20% of breast cancer cases in Europe (over 117,000 patients).[7] A lack of effective screening for younger women means those affected by breast cancer are not diagnosed and treated as soon as they could be. As a result, women who are diagnosed at the age of 40 years or younger are currently 30% more likely to die from breast cancer than women diagnosed at the age of 51 to 60.[8]

Meanwhile, over screening causes problems for older women who are at low risk of breast cancer. Over screening of low-risk women over 50 leads to false positives, personal inconvenience and overdiagnosis.[9]

To improve the effectiveness of mammographic screening for breast cancer there needs to be a risk-based way to identify subgroups of women for targeted screening programmes. Targeted screening based on genetic risk could allow precision prevention of breast cancer. This could decrease the societal and economic burden of the condition, while adding healthy life years for participating women.[10]

The solution

The BRIGHT project team are working on a genetics-based test for breast cancer risk, to identify those who would benefit from targeted breast cancer screening. The solution is a predictive, polygenic risk score test, which has been evaluated and validated using population data from both the Estonian and UK Biobank.

A polygenic risk score tells you how a person’s breast cancer risk compares to others with a different genetic constitution. The test enables targeted screening through genetic risk estimation, for women from the of age 35. Test results will be provided with follow-up actions for future risk management.

The solution will help to enable the identification of breast cancer in younger women whose condition may have otherwise been missed or diagnosed at a later stage. It will also help to reduce mortality rates in the younger age group.

Expected impact

The project team plan to develop their test so that it complies with The European Union In Vitro Diagnostics Regulation. They will conduct three clinical pilot studies and cost-efficiency analyses of the precision breast cancer screening approach using Estonia, Sweden, and Portugal as initial test sites. Their aim is to drive large-scale adoption of their polygenic risk score approach to breast screening management.

By enabling precision prevention by targeted screening, BRIGHT promises to improve patient outcomes and significantly reduce breast cancer mortality. The project also has the potential to reduce the societal burden of breast cancer and save costs from the treatment of advanced cancer. Ultimately, BRIGHT promises to increase quality of life for women with a high risk of breast cancer, through early detection and more successful treatment.

External Partners
  • Antegenes OÜ
  • Estonian Health Insurance Fund
References

[1] Based on calculations using data from: (IARC), T., 2022. Global Cancer Observatory. [online] Gco.iarc.fr. Available at: <https://gco.iarc.fr/> [Accessed 11 April 2022].

[2] Based on calculations using data from: (IARC), T., 2022. Global Cancer Observatory. [online] Gco.iarc.fr. Available at: <https://gco.iarc.fr/> [Accessed 11 April 2022].

[3] Marmot, M. G. et al. (2013). The benefits and harms of breast cancer screening: an independent review. British journal of cancer, 108(11), 2205–2240.

[4] Myers, E. R. et al. (2015). Benefits and Harms of Breast Cancer Screening: A Systematic Review, JAMA. 314(15, 1615–1634.

[5] Tabár, L. et al. (2019). ‘The incidence of fatal breast cancer measures the increased effectiveness of therapy in women participating in mammography screening’, Cancer, 125(4), 515–523.

[6] Fasching, P. A., et al. (2011). Breast Cancer Risk – Genes, Environment and Clinics. Geburtshilfe und Frauenheilkunde, 71(12), 1056–1066.

[7] (IARC), T., 2022. Global Cancer Observatory. [online] Gco.iarc.fr. Available at: <https://gco.iarc.fr/> [Accessed 11 April 2022].

[8] Partridge, A. H. et al. (2016). Subtype-Dependent Relationship Between Young Age at Diagnosis and Breast Cancer Survival.  Journal of Clinical Oncology, 34(27), 3308–3314.

[9] Houssami, N. (2017). Overdiagnosis of breast cancer in population screening: does it make breast  screening worthless?’, Cancer biology & medicine, 14(1), 1–8.

[10] Mühlberger, N. et al. (2021). Cost effectiveness of breast cancer screening and prevention: a systematic review  with a focus on risk-adapted strategies. The European journal of health economics : HEPAC : health economics in prevention and care. Germany, 22(8), 1311–1344.

Neeme Tõnisson
| Research Professor | Estonian Biobank / Institute of Genomics, University of Tartu
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Peter Padrik
| CEO / Oncologist | Antegenes OÜ
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