Abstract
BACKGROUND: Coronary artery disease (CAD) is associated with cancer. The role of inflammation in the association of CAD with cancer remains unclear. The study investigated whether inflammation could impact the relationship between CAD and lung cancer. METHODS: The study involved 96 newly diagnosed lung cancer patients without receiving anti-cancer therapy and 288 matched non-cancer patients. All the patients underwent coronary angiography and were free from previous percutaneous coronary intervention or coronary artery bypass grafting. SYNTAX score (SXscore) were used to assess severity of CAD. High SXscore (SXhigh) grade was defined as SXscore > 16 (highest quartile). Neutrophil-to-lymphocyte ratio (NLR) served as an inflammatory biomarker. NLR-high grade referred to NLR > 2.221 (median). RESULTS: Among 384 study patients, 380 patients (98.96%) had NLR value (median: 2.221, interquartile range: 1.637-3.040). Compared to non-cancer patients, lung cancer patients had higher rate of SXhigh among total study patients (P = 0.014) and among patients with NLR-high (P = 0.006), but had not significantly higher rate of SXhigh among patients with NLR-low (P = 0.839). Multivariate logistic regression analysis showed that SXhigh was associated with lung cancer [odds ratio (OR) = 1.834, 95% CI: 1.063-3.162, P = 0.029]. Subgroup analysis showed that SXhigh was associated with lung cancer among patients with NLR-high (OR = 2.801, 95% CI: 1.355-5.794, P = 0.005), however, the association between SXhigh and lung cancer was not significant among patients with NLR-low (OR = 0.897, 95% CI: 0.346-2.232, P = 0.823). CONCLUSIONS: Inflammation could lead different association between anatomical severity of CAD and lung cancer. Severity of CAD was significantly associated with increased risk of lung cancer among patients with high inflammation rather than among patients with low inflammation.