Coronary-artery calcium (CAC) measured automatically on radiotherapy-planning CT scans in women being treated for breast cancer may be used to spot those at increased risk for cardiovascular disease, researchers say. "We've shown that we can use routine radiotherapy CT scans to indicate which breast cancer patients are most likely to develop cardiovascular disease," said Dr. Helena M. Verkooijen of University Medical Center Utrecht in the Netherlands. "Now we need to do more research to find out what can be done to help minimize this risk, for instance whether patients' cardiovascular health should be monitored or treated," she told Reuters Health by email. Cardiovascular disease (CVD) is common in women with breast cancer and in older patients competes with breast cancer as the leading cause of death, Dr. Verkooijen and colleagues note in JAMA Oncology. CAC on CT scans is an independent risk factor for CVD, they add, but CAC scoring "is usually performed manually and can be tedious and time consuming." However, the team has developed a deep-learning calcium-scoring algorithm for automated CAC scoring on dedicated cardiac CT scans. To examine the utility of this information, the researchers studied data on close to 16,000 patients with breast cancer who received radiotherapy between 2005 and 2016. Their mean age at CT scan was 59 years. CAC scores were used to classify CVD evidence in patients via Agatston risk categories (0, 1-10, 11-100, 101-399, >400 units). Overall, 70% of patients had no CAC. Scores of 1 to 10 were seen in 10%, 11 to 100 in 11.5%, 101 to 400 in 5.2%, and greater than 400 in 3.1%. Over a median follow-up of 51.2 months, CVD events occurred in 5.2% in patients with no CAC and in 28.2% in those with CAC scores higher than 400. Compared with patients without CAC, the adjusted risk of fatal and nonfatal CVD was 1.1, 1.8, 2.1 and 3.4 higher in patients with a CAC score of 1 to 10, 11 to 100, 101 to 400, and greater than 400, respectively. Coronary-artery calcium was particularly strongly associated with coronary-artery disease in those with the highest scores (HR, 7.8). The association between CAC and CVD was strongest in patients treated with anthracyclines and those who received a radiation boost. "Timely and accurate identification of high-risk patients might allow mitigation of cardiovascular risk, including management of CVD risk factors and switching to less cardiotoxic treatment regimens," the researchers say. Dr. Sherry-Ann Brown, director of Cardio-Oncology at the Medical College of Wisconsin, in Milwaukee, told Reuters Health by email that "according to this cohort study, CAC scoring on radiotherapy-preparation CT scans can be used as a quick and low-cost method to classify patients with breast cancer who are at a higher risk of CVD, enabling CVD risk-reduction measures to be implemented." "This," she added, "is something we have wanted to see and study for a long time, as we recognize more and more the potential value of synergistic screening in cardiology and medical and radiation oncology. Combining cardiovascular risk screening with treatment planning for breast cancer can enhance and optimize multidisciplinary preventive care and management for individuals with cancer." Dr. Brown was not involved in the study. —David Douglas Source
