News: Understanding the genetics of breast cancer | Breast Cancer UK

News: Understanding the genetics of breast cancer

Published 3 May 2016

New research that identifies gene mutations in breast tumours could lead to improved, targeted treatments for breast cancer, but questions remain as to what causes so many gene mutations in the first place.   

International researchers led by Dr Nik-Zainal from the Wellcome Trust Sanger Institute, Cambridge, have sequenced the genomes (DNA) from breast tumours of 560 individuals and identified 93 genes that, if mutated, can lead to breast cancer.

The work, published yesterday in Nature (1), and Nature Communications (2), provides a comprehensive understanding of the genetic changes associated with breast cancer and may help further our understanding of some of the important biological processes associated with the disease. The research is likely to lead to improved, targeted treatments for the many different types of breast cancers that can arise.

The 93 genes associated with breast cancer included 5 not previously identified. These mutated genes and their protein products may be targets for new drugs. Researchers also identified 20 “mutational signatures” – characteristic DNA patterns - that influence tumour development, including 13 new signatures.

Furthermore, they found that women with BRCA1 or BRCA2 mutations tended to have different mutational signatures, compared to those with other mutations.

Breast Cancer UK welcomes the results of the research, which may lead to better, more targeted treatments. However, the origins of the breast cancers are still unclear. What is causing the genes to mutate?

We know some of the probable causes – alcohol, obesity, radiation exposure, accumulation of random mutations due to ageing - but it is still unclear what is responsible for around a third to a half of all breast cancer cases.

Until we understand this, prevention will be elusive. We continue to urge the government to direct more of its research spending toward understanding the causes of breast cancer, including those associated with environmental chemicals.

Read our letter to George Osbourne regarding spending on prevention 


1. Nik-Zainal, S. et al. (2016). Landscape of somatic mutations in 560 breast cancer whole-genome sequences. Nature. DOI:10.1038/nature17676. Published early online May 2.

2. Morganella, S. et al. (2016). The topography of mutational processes in breast cancer genomes. Nature Communications 7. DOI:10.1038/ncomms11383. Published early online May 2.

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