The risk of heart disease in breast cancer patients can be predicted from routine examinations

Automated analysis of routine breast cancer screenings can predict which women have a one-in-four greater risk of developing cardiovascular disease, according to research presented at the 12th European Breast Cancer Conference.

Women who have been treated for breast cancer may have an increased risk of developing cardiovascular disease, and in some groups the risk of dying from cardiovascular disease is higher than the risk of dying from breast cancer.

The new study shows that those who are most at risk can be detected by computer analysis of the CT scans taken to plan cancer treatments. The researchers say that identifying patients at increased risk for cardiovascular disease could allow steps to be taken to reduce risk.

The research was presented by Professor Helena Verkooijen, from the Division of Imaging and Oncology of the Utrecht University Medical Center in the Netherlands. She said: “We have seen a great improvement in breast cancer survival, thanks in part to better treatment. However, treatments have side effects and some treatments, such as radiation therapy and certain types of anticancer drugs, can Increasing the risk of cardiovascular disease. In my opinion, treating breast cancer means striking the right balance between maximizing the chances of addressing the tumor and minimizing the risks of side effects, including the risk of cardiovascular disease. “

The study included around 14,000 breast cancer patients who were treated with radiotherapy in three large hospitals in the Netherlands between 2005 and 2016.

Professor Verkooijen and her colleagues used a measure called the coronary artery calcium score (CAC). This is an estimate of the amount of calcium in the walls of the heart arteries and is known to be a strong risk factor for cardiovascular disease because calcifications can lead to narrowing or blockage of blood vessels.

The researchers developed a deep learning algorithm that could measure the presence and extent of coronary artery calcifications from CT scans already underway to help plan each woman’s radiation treatment. This allowed them to automate CAC measurement for all women with minimal additional workload.

The researchers followed the women for an average of 52 months to see if any of them developed cardiovascular disease. In women without calcifications (zero score), 5% went to hospital or died of cardiovascular disease. In women with a score between one and ten, 8.9% were hospitalized or died of cardiovascular disease. In women with a score of 11-100, the figure was 13.5%, in women with a score of 101-400 it was 17.5% and in women with a score greater than 400 it was 28, 3%.

When the researchers took into account the women’s age and the year they were diagnosed, they found a 3.7 times higher risk of cardiovascular disease in women with the highest score (above 400), compared to women without calcifications. . In women who were treated with a particular type of chemotherapy called anthracycline, the association between a high CAC score and cardiovascular risk was even stronger.

The researchers acknowledge that they were unable to account for other risk factors for cardiovascular disease, such as smoking, high blood pressure and diabetes, in this study, although these are factors they are looking at in another study.

Professor Verkooijen said: “We believe this is the first time that someone has conducted a large-scale study like this. We have shown that we can use routine CT scans to indicate which breast cancer patients are most likely to develop cardiovascular disease. Now more research is needed to find out what can be done to help minimize this risk, for example whether to monitor or treat the cardiovascular health of patients. “

The researchers are now working to put their technique to use for predicting cardiovascular disease risk in various radiotherapy units in the Netherlands. Higher risk patients in this study will be offered more cardiovascular screenings and lifestyle advice, and their CAC score will be used to plan their breast cancer treatment.

Professor Nadia Harbeck, from the University of Munich (LMU) in Germany, chairs the 12th European Conference on Breast Cancer and was not involved in the research. She said: “Our key goal is to treat breast cancer effectively. However, it is equally important that we do not over-treat patients because cancer therapies can have serious, long-term side effects.”

“This is a smart study because it shows us how the CT scans that we are already taking can also be used to find out which women are at the highest risk for cardiovascular disease. We expect more results from these researchers and hope they can show us how best to help women. who have an increased risk of cardiovascular disease. ”

Provided by the European Organization for Research and Treatment of Cancer