Lung cancer screening using low-dose computed tomography (CT) has become an essential tool for early detection among high-risk individuals. This initiative primarily aims to identify lung cancer in its nascent stages, improving survival rates. However, these scans often reveal more than just pulmonary abnormalities. Coronary artery calcium (CAC), a hallmark of coronary artery disease, is frequently identified during such imaging. While this finding is incidental, it provides a critical opportunity to address a parallel health challenge: cardiovascular disease, another leading cause of death. By incorporating cardiovascular risk assessment into lung cancer screening programmes, healthcare providers can tackle two major public health issues simultaneously, leveraging the existing infrastructure for broader preventive care.

 

The Overlap of Risks

Lung cancer and coronary artery disease are inextricably linked through shared risk factors. Smoking, a primary cause of lung cancer, also accelerates atherosclerosis, a key mechanism underlying coronary artery disease. Other factors, including hypertension, dyslipidaemia and diabetes, are similarly prevalent in individuals undergoing lung cancer screening. These overlapping risks make the population being screened for lung cancer particularly predisposed to undiagnosed coronary artery disease. Studies have consistently demonstrated a high prevalence of CAC among those screened, with substantial numbers showing extensive calcification, often indicative of advanced atherosclerosis.

 

The prognostic implications of CAC are significant. Extensive calcification is a well-established predictor of adverse cardiovascular outcomes, including myocardial infarction, stroke and sudden cardiac death. Furthermore, the risk is independent of other traditional cardiovascular risk factors, underscoring the importance of its detection. In the context of lung cancer screening, CAC detection enables clinicians to identify patients who may benefit from preventive interventions, such as statin therapy or lifestyle modifications. These measures, if initiated early, can significantly reduce the risk of cardiovascular events, complementing the primary goal of reducing lung cancer mortality.

 

Prognostic Value of Coronary Artery Calcium

CAC identified during lung cancer screening is more than a coincidental finding; it serves as a robust marker of cardiovascular risk. Research indicates that extensive CAC, often defined by an Agatston score exceeding 400, is associated with a markedly increased risk of all-cause mortality and cardiovascular events. Importantly, this predictive value persists even when adjusted for competing risks such as cancer-related mortality. In high-risk populations, the annualised rates of cardiovascular events and deaths are significantly higher among those with extensive CAC compared to those with minimal or no calcification. This highlights the potential of CAC as a stratification tool for cardiovascular risk within lung cancer screening programmes.

 

The ability to predict cardiovascular outcomes through CAC assessment provides a compelling argument for its routine evaluation during lung cancer screenings. Patients with advanced CAC can be prioritised for targeted interventions, ranging from pharmacological treatments to closer clinical monitoring. Moreover, the data underscores the broader preventive potential of lung cancer screening programmes, shifting them from a single-disease focus to a more integrated health initiative. By addressing cardiovascular risks, these programmes can provide holistic care, reducing the burden of two major causes of death and improving overall population health.

 

Challenges and Opportunities in Integration

Despite its potential, incorporating CAC assessment into lung cancer screening programmes is not without challenges. One of the key issues lies in determining the appropriate clinical response to CAC findings. While extensive CAC warrants preventive measures, the management of mild to moderate calcification is less clear. Unnecessary testing or overtreatment could burden healthcare systems, creating inefficiencies and potentially causing patient anxiety. Striking a balance between vigilance and restraint is essential to maximise the benefits of this integrated approach.

 

Logistical hurdles also exist. Assessing CAC during lung cancer screenings requires additional training for radiologists to recognise and quantify calcification accurately. Furthermore, standardised protocols must be developed to guide the interpretation of CAC findings and subsequent clinical actions. These protocols should aim to integrate cardiovascular risk management seamlessly into existing screening workflows, ensuring minimal disruption while enhancing the overall value of the screening process.

 

However, these challenges are surmountable and pale in comparison to the potential benefits. The integration of CAC assessment represents a cost-effective approach to preventive healthcare, leveraging existing infrastructure to address multiple health risks simultaneously. This dual-purpose use of low-dose CT scans exemplifies efficiency in resource utilisation, aligning with the broader goals of public health to reduce morbidity and mortality across populations. Moreover, it paves the way for a multidisciplinary approach to patient care, promoting collaboration between oncologists, cardiologists and primary care providers.

 

Lung cancer screening programmes offer an unprecedented opportunity to enhance cardiovascular health by incorporating the assessment of coronary artery calcium. The high prevalence and prognostic significance of CAC in screening populations underscore its potential as a valuable marker of cardiovascular risk. By addressing both lung cancer and coronary artery disease within a single screening initiative, healthcare systems can achieve a dual impact, improving outcomes for two of the leading causes of death.

 

This integrated approach represents a paradigm shift in preventive healthcare. Beyond the early detection of lung cancer, it highlights the importance of a comprehensive view of patient health, recognising the interplay of various risk factors and conditions. While challenges in implementation remain, the potential to transform lung cancer screening into a holistic preventive strategy is both innovative and essential. As healthcare systems worldwide strive to optimise resources and improve population health, embracing the dual benefits of lung cancer screening could set a new standard for integrated care.

 

Source: Canadian Medical Association Journal

Image Credit: iStock


References:

Caires MC, Mbondo Kasuku K, Mengesha B et al. (2024) Prognostic importance of extensive coronary calcium on lung cancer screening chest computed tomography. CMAJ, 196:E1362-9.



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lung cancer screening, cardiovascular health, coronary artery calcium, low-dose CT, dual benefits, early detection, preventive care, public health Low-dose CT lung cancer screening offers dual benefits, detecting early-stage cancer and coronary artery calcium to address cardiovascular risks.