Protein Programmed Death-Ligand 1 Expression in Non-Small Cell Lung Cancer (NSCLC) and Its Correlation to Smoking Status in North Sumatera Population

Abstract

Tobacco smoking is associated to the increase risk of lung cancer, and smoking could also trigger the tumour proportion score from programmed death ligand (PD-L1). This study aims to identify the correlation of non-small cell lung cancer (NSCLC) with the PD-L1 expression and smoking profile on the North Sumatra Population. Lung cancer is a significant health issue worldwide, where it is the leading cause of death in men. In Indonesia, lung cancer ranks second in terms of incidence overall and first in men. The 5-year prevalence of lung cancer in Indonesia is 10.85 per 100,000 population. The case fatality rate (CFR) for lung cancer in Indonesia is 86.91%. This research implemented a descriptive study with cross-sectional design. 100 of patients with lung cancer were recruited, however; only 52 patients were diagnosed with NSCLC based on histopathological results. Subsequently, 35 samples were included in accordance to inclusion criteria. Staining on Ventana 22C3 platform was performed in Dharmais Cancer Hospital, and tumour proportion score was assessed by two experts of Pathologist. This study was carried out from August 2019 to September 2020. Results: Characteristics of patients with NSCLC to the PD-L1 expression were found more in male patients with percentage of 88.6%, whereas the most common type of cancer is adenocarcinoma, accounting for 97.14% of cases with mild degree smoking index for 45.7% (Brinkman index) and IV-stage of clinical status for 68.6%. The tumour proportion score with 1-49% was 51.4% with high expression of PD-L1 (positive) for 74.28%, while lower expression of PD-L1 accounted for 45%. There is a correlation between PD-L1 expression and smoking status in NSCLC patients, with p-value of 0.037 (<0.05).