Multivariable analysis from a new study demonstrates that the computed tomography (CT)-based coronary artery calcium (CAC) score offers better preoperative prognostic capability than coronary artery stenosis severity or the CT-based fractional flow reserve (CT-FFR) for predicting long-term survival in elderly patients with lung cancer who undergo surgery.
For the retrospective study, recently published in Academic Radiology, researchers compared the CACS, CT-FFR and coronary artery stenosis severity in a total cohort of 896 elderly patients with lung cancer.
In a multivariable analysis, the study authors found that patients with a preoperative CACS > 40 had a 53 percent higher risk of all-cause mortality after surgery and a 142 percent higher risk of non-lung cancer death.
The researchers noted that CT-FFR < 0.8 and moderate to severe coronary artery stenosis had no significant impact upon overall survival rate and non-lung cancer mortality in the cohort.
“The results showed that CACS performed better than the severity of coronary artery stenosis and CT-FFR in assessing the prognostic impact of coronary artery factors in elderly patients with lung cancer. … CACS exhibits greater sensitivity in detecting coronary atherosclerosis before it causes coronary artery stenosis and myocardial ischemia, which is crucial for risk assessment in patients with asymptomatic atherosclerosis,” wrote lead study author Zetao Liu, M.D., who is affiliated with the Department of Thoracic Surgery at the West China Hospital and Sichuan University in Sichuan, China, and colleagues.
Based on multivariable analysis, the researchers developed and assessed a predictive nomogram that emphasized CACs > 40 and six other independent factors, including smoking history, pathological type, pathological stage, and surgical procedure, for evaluating long-term survival in this patient population.
The nomogram demonstrated higher area under the receiver operating characteristic curves (AUCs) than tumor node metastasis (TNM) staging for predictions of one-year (90.9 vs. 64.5), three-year (83.4 vs. 62.4) and five-year overall post-op survival (77.9 vs. 63.3), according to the study authors.
Three Key Takeaways
1. CACS is a superior prognostic marker. Preoperative coronary artery calcium score (CACS) outperformed both CT-FFR and coronary artery stenosis severity in predicting long-term survival in elderly lung cancer patients undergoing surgery. The study authors noted that CACS > 40 was linked to significantly higher all-cause and non-lung cancer mortality.
2. Tailored treatment approaches. A CACS > 40 was associated with a significantly higher risk of non-lung cancer death in patients undergoing lobectomy but had no significant effect in those undergoing sublobar resection, supporting more conservative treatment (e.g., SBRT or sublobar surgery) for high-risk patients.
3. Enhanced prognostic tool. The nomogram incorporating CACS and six other clinical variables (e.g., smoking history, pathological stage) provided superior predictive accuracy for 1-, 3-, and 5-year survival compared to traditional TNM staging.
The study authors also found that a CAC > 40 had a significant impact on non-lung cancer death risk for patients who had lobectomy procedures (hazard ratio of 2.94) but no significant impact upon survival rates for patients who had sublobar resection.
“Considering the potential risk of coronary artery disease in elderly lung cancer patients and the close relationship between CACS and non-lung cancer death, CACS may serve as a crucial marker to separate out patients at high risk of non-lung cancer death,” noted Liu and colleagues. “For these identified patients, less aggressive cancer treatments, such as stereotactic body radiation therapy (SBRT) or sublobar resection, may be considered to achieve greater survival benefits.”
(Editor’s note: For related content, see “Meta-Analysis Assesses Prognostic Role of CT-Based Coronary Artery Calcification in Patients with Lung Cancer,” “Computed Tomography Study Examines Potential of Automated Coronary Artery Calcium Scoring with Deep Learning” and “FDA Clears Updated AI Software for CT-Based Coronary Artery Calcium Assessment.”)
Beyond the inherent limitations of a single-center retrospective study, the authors noted that the performance of revascularization procedures in some patients prior to surgery may have affected the assessment of prognostic indicators. The researchers also noted that major adverse cardiovascular events (MACEs) were not assessed and acknowledged that poor image quality of CCTA for some patients prevented software assessment for CACS scores.
