King's College London

Studying a person’s genetic makeup can predict if they will go on to develop invasive breast cancer after abnormal cells have been found in their breast tissue.

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

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.

Breast cancer is the most common cancer in women, with around 55,000 women diagnosed each year in the UK. The earlier breast cancer is diagnosed, the better the chance of successful treatment so being able to predict who might be at risk is crucial.

“The results of this study show that the genetic risk score could be useful in this prediction, meaning that treatments could be more personalised, 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. Focusing more on individual risk could improve overall well-being and help reduce the stress that comes with being overtreated.”

Professor Elinor Sawyer, senior author and a Consultant Clinical Oncologist at King’s College London, said:

In my clinical practice, I see many women diagnosed with DCIS or LCIS. Until now, treatment decisions have mostly been based on how the cells look under a microscope. Our research shows that a genetic risk score can also help predict which women are more likely to develop invasive breast cancer.

Dr Simon Vincent, chief scientific officer at Breast Cancer Now, said: “This study offers evidence that genetic risk scoring could be a useful tool for predicting future breast cancer in women diagnosed with ductal carcinoma in situ or lobular carcinoma in situ – which are the most common pre-invasive abnormal cells found in the breast. Understanding who is most likely to develop invasive disease in the future could help to tailor care for those most at risk, inform treatment decisions and improve individual wellbeing for women.

“While these initial findings show promise for paving the way for more personalised treatment decisions in the future, more research is needed before this test can be used more widely."