For the first time, researchers at King’s College London (KCL) have shown the connection between a person’s genetic risk score and their risk of developing the disease after irregular cells have been detected in breast tissue, KCL informs.

The research, published in Cancer Epidemiology, Biomarkers & Prevention and funded by Breast Cancer Now, included over 2,000 women in the UK who had been tested for 313 genetic changes, known as a genetic risk score.

These patients had already been diagnosed with either ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS)—the most common types of abnormal cells found in breast tissue.

A genetic risk score estimates a person's inherited likelihood of developing a disease or trait by combining the influence of multiple common genetic variants.

Screening allows breast cancers to be caught at an earlier stage and is typically offered every three years to women aged 50 to 71 via the NHS Breast Screening Programme.

However, this has led to a large number of women being diagnosed with abnormal cells in their breast tissue which are not invasive cancer but may become cancer in the future.

At the moment it is not possible to know which women with abnormal cells will go on to develop invasive breast cancer, so they are offered a variety of treatments. This can range from increased surveillance to surgery, radiotherapy and anti-estrogen therapy.

The results of this study show that the genetic risk score could be useful in this prediction, meaning that treatments could be more personalized, rather than giving everyone the same treatment approach. In some cases, this could avoid unnecessary invasive treatments altogether, which can take a toll on patients both physically and emotionally.

Until now, treatment decisions have mostly been based on how the cells look under a microscope. But this research shows that a genetic risk score can also help predict which women are more likely to develop invasive breast cancer.

The study authors stressed the importance of taking into account not only the microscopic characteristics of the cells, but also genetic risk and lifestyle factors, to provide women with more accurate information about their personal risk and help them make informed treatment choices.

However, the researchers note that while these initial findings show promise for paving the way for more personalized treatment decisions in the future, more research is needed before this test can be used more widely.