Association between Serum Angiotensin-converting Enzyme 2 Level with Postoperative Morbidity and Mortality after Major Pulmonary Resection in Non-small Cell Lung Cancer Patients

BACKGROUND: To explore the association between serum angiotensin-converting enzyme 2 (ACE2) levels and postoperative morbidity and mortality after major pulmonary resection in non-small cell lung cancer (NSCLC) patients. METHODS: Preoperative and postoperative serum ACE2 levels in 320 NSCLC patients who underwent major pulmonary resection were measured. The serum ACE2 levels on postoperative day 1 were divided into quartile categories. RESULTS: After adjustment for age, sex, body mass index, current smoking status, forced expiratory volume in 1 second, coronary heart disease, hypertension, diabetes mellitus, chronic obstructive pulmonary disease, and tumour clinical stages, the risk of developing postoperative morbidities was significantly higher in the lowest serum ACE2 level quartile than in the highest quartile (hazard ratio, 2.12; 95% CI, 1.57-6.23; p=0.008). NSCLC patients with a serum ACE2 level ≤3.21 ng/mL had significantly higher rates of pneumonia, pleural effusion, atrial fibrillation as well as higher in-hospital mortality after major pulmonary resection, compared with those with a serum ACE2 level >3.21ng/mL. CONCLUSIONS: The serum ACE2 level one day post surgery is an independent risk factor for postoperative morbidities after major pulmonary resection in NSCLC patients. Thus, it could be used as a prognostic factor for postoperative morbidities after major pulmonary resection in NSCLC patients.