Association of Low Body Mass Index with Poor Clinical Outcomes after Resection of Non-small Cell Lung Cancer

Background/Aim: This study was performed to evaluate the influence of the body mass index (BMI) on disease-free survival and overall survival (DFS and OS) in patients with resected non-small cell lung cancer (NSCLC). Patients and Methods: Overall, 546 of 780 (70%) patients with stage I to III NSCLC who underwent surgical resection were randomly selected. The patients were subdivided into three groups: low BMI (<18.5 kg/m²), normal BMI (18.5 to <25.0 kg/m²), and high BMI (≥25.0 kg/m²). Cox proportional hazards regression analyses were performed to identify variables associated with survival. Results: In all patients, a low BMI was an independent prognostic factor for both DFS and OS (p=0.0175 and p=0.0134, respectively). In patients with stage I, a low BMI was also an independent prognostic factor for both DFS and OS (p=0.0066 and p<0.0001, respectively). Conclusion: A low BMI was an independent prognostic factor after surgical resection of stage I NSCLC. Molecular targeted therapies, such as epidermal growth factor receptor inhibitors, anaplastic lymphoma kinase-tyrosine kinase inhibitors, and immune checkpoint inhibitors targeting the programmed cell death-1/programmed cell death-ligand 1 (PD-L1) pathway have greatly improved the clinical course for patients with non-small cell lung cancer (NSCLC), especially advanced-stage NSCLC (1-7). However, lung cancer remains the leading cause of cancer-related death worldwide (8). Even in patients with stage I to IIIA NSCLC, the clinical course is unsatisfactory despite the fact that surgical resection is the main treatment option (9). Therefore, it is important to identify useful, simple, and inexpensive prognostic markers in patients with resectable NSCLC.