Scientists identify 4 new genes associated with breast cancer

An international team of scientists from Canada and the UK has identified four new genes associated with breast cancer, and potentially more, that could be included in tests to identify women at increased risk.

Globally, more than 2.3 million women suffer from breast cancer, and it is the second leading cause of cancer death among women.

Current genetic tests for breast cancer only consider a few genes, such as BRCA1, BRCA2, and PALB2.

However, these only explain a minority of the genetic risk, suggesting that more genes remain to be identified.

The study, published in the journal Nature Genetics, found evidence for at least four new breast cancer risk genes, with suggestive evidence for many others.

The identification of these new genes will contribute to our understanding of the genetic risk of breast cancer.

This new knowledge will help improve risk prediction by better identifying those women at higher risk of the disease.

This will better inform approaches to breast screening, risk reduction and clinical management.

The discovery of these novel genes also provides crucial information on the biological mechanisms underlying cancer development, potentially opening the way to identifying new treatments.

The aim is to integrate this information into a comprehensive risk prediction tool currently used worldwide by health professionals.

"Improving genetic counselling for high-risk women will promote shared decision-making regarding risk reduction strategies, screening and determination of treatment options," said Professor Jacques Simard of Universite Laval in Quebec, Canada.

“Although most of the variants identified in these new genes are rare, the risks can be significant for women who carry them. For example, alterations in one of the new genes, MAP3K1, appear to give rise to a particularly high risk of breast cancer,” added Simard, a researcher at the Genomics Center of the CHU de Quebec-Universite Laval Research Center.

The team studied genetic changes in all genes in 26,000 women with breast cancer and 217,000 women without breast cancer. These included women from eight countries in Europe and Asia.

Before the findings can be used in a clinical setting, scientists need to validate the results in further datasets.

"We need additional data to determine more precisely the risks of cancer associated with variants in these genes, to study the characteristics of the tumours, and to understand how these genetic effects combine with other lifestyle factors affecting breast cancer risks," said Professor Douglas Easton, Director of the Centre for Cancer Genetic Epidemiology of the University of Cambridge.