CT for Early Lung Cancer Detection Also Helps Identify Coronary Artery Blockage

Lung Cancer and Coronary Artery Disease: Two Silent Diseases Together

Lung cancer is the leading cause of cancer-related deaths worldwide. Meanwhile, narrowing in the vessels supplying the heart, known as coronary artery disease (CAD), is the most common cause of cardiovascular deaths. Both diseases often progress without early symptoms and increase mortality. A new study suggests that lung cancer screening with low-dose computed tomography (CT) may also detect signs of CAD, such as coronary artery calcification (CAC), in people without cardiac symptoms. This could mark a major turning point because a single screening method may help address two important causes of death.

On 2 December 2024, Canadian Medical Association Journal published this study by Caires and colleagues, shedding light on the potential role of lung cancer screening in diagnosing CAD.

Study Background: Why Does It Matter?

Low-dose chest CT screening is widely used to detect lung cancer early in high-risk individuals. However, scans may also reveal other important findings, such as calcification (calcium deposits) in the coronary arteries. Calcification indicates plaque accumulation in these arteries and is an important biomarker associated with increased cardiovascular risk.

Senior author Dr. Gary Small of the University of Ottawa Heart Institute noted that, beyond reducing deaths from lung cancer, these scans could also help diagnose and stratify the risk of coronary atherosclerosis, the second most common cause of death in middle-aged people. This was another potential benefit he highlighted.

Study Details and Findings

The study involved 1486 high-risk patients in the Ontario Health Lung Cancer Screening Pilot Program between 2017-2018. Their demographic characteristics were as follows:

• 52% of participants were men.
• The mean age was 66.
• 68% of patients (1017 people) were current smokers.

Results:

• Coronary artery calcification was detected in 83% of participants (1232 people).
• In 30% of these individuals (439 people), calcification was considered extensive.

Study Implications: Potential Survival Benefits for Both Diseases

Researchers noted that chest CT screening might reduce deaths from CAD as well as lung cancer. However, they emphasized that this depends on several critical factors:

1. Physicians' Ability to Interpret and Manage Findings: Incidental findings such as coronary artery calcification may lead to unnecessary investigations and excessive interventions.
2. Developing Treatment Strategies: Appropriate treatments must be identified and implemented for people with coronary calcification.

Potential Risks:

Alongside the benefits of low-dose CT screening, the risks of unnecessary intervention must be considered. The study particularly highlighted the need to integrate cardiovascular prevention strategies into lung cancer screening programs.

What Should Happen Next?

Researchers called for further studies on managing incidental findings such as coronary artery calcification. A multidisciplinary approach to their management could improve survival in both diseases.

This pilot program by Dr. Small and colleagues offers a new public health approach that addresses two serious diseases together. A clear understanding of the risks and benefits of these methods among clinicians and patients will be critical to the success of such programs.

Conclusion: Two Important Risks, One Solution

Low-dose chest CT screening could become a transformative tool for cardiovascular health as well as lung cancer screening. This innovative approach may broaden the scope of future health screening programs. Public health policies and clinical practice should therefore adopt such integrated approaches, as the researchers recommend.

Note: The findings highlight the importance of individualized treatment approaches in disease management, in addition to early detection and prevention.