Lung cancer screening with low-dose chest computed tomography (CT) may reveal more than simply lung cancer. According to new research published in CMAJ (Canadian Medical Association Journal), these CTs can detect coronary artery calcium, a high-risk factor for coronary artery disease (CAD), in patients without cardiac symptoms.

"Lung cancer screening, while mainly meant to lower the number of deaths from lung cancer, could also help fight coronary atherosclerosis, which is the second most common cause of death in middle-aged adults, by finding it and figuring out who is at risk," writes Dr. Gary Small from the University of Ottawa Heart Institute in Ottawa, Ontario, with other authors.

As part of the Ontario Health Lung Cancer Screening Pilot for People at High Risk, 83% (1232) of the 1486 people screened for lung cancer between March 2017 and November 2018 had coronary artery calcium, with high levels in 30% (439). More than half of the patients (52% were men), the average age was 66 years, and 68% (1017) were current smokers.

Because lung cancer is the main cause of cancer deaths in Canada, screening programs across the country have implemented low-dose CT for those at risk. These CTs can also easily detect coronary calcification, which is a sign of coronary artery disease, the leading cause of cardiac death.

"If appropriate therapeutic responses are instituted, lung CT findings could affect survival from 2 leading causes of death: lung cancer and coronary artery disease," the paper's authors note.

The success of this pilot program will depend on how clinicians interpret and manage coronary artery calcium readings. However, clinicians must be mindful that there may be negative consequences, such as inappropriate examination following coincidental detection.

The authors advocate for additional research into how to handle people with accidentally identified coronary artery calcium but also recommend that "continued attention to cardiovascular disease prevention is warranted and could be amalgamated into lung cancer screening initiatives to promote health."