Understanding Non-Small Cell Lung Cancer Heterogeneity - Histopathological and Molecular Perspectives: A Retrospective Cross-Sectional Study in A Tertiary Care Centre of Karnataka, India

Abstract

Introduction: Non-small cell lung cancer (NSCLC) is the commonest lung malignancies, and early description of the histopathological and molecular subtype of lung cancer has important prognostic relevance and management implications. 
Objective: To assess histopathological and molecular subtypes of NSCLC and the associated factors.
Methodology: This retrospective study with universal sampling was conducted at a tertiary care hospital in Karnataka, between January 2016 and September 2019. NSCLC diagnosis was confirmed through both CT imaging and histopathological examination following lung biopsy. The research encompassed a thorough examination of clinical data, histopathological subtypes, and the molecular mutation status of the cases. Data entry was carried out using Microsoft Excel, while statistical analysis was performed with SPSS version 22. 
Results: A total of 176 cases (125 male, 51 female) that fulfilled the inclusion criteria were included in the present study with mean age of 61.8 (±11.2) years. The most prevalent subtype of Non-Small Cell Lung Cancer (NSCLC) was squamous cell carcinoma (37.5%), followed by acinar (21.6%) and lepidic subtypes (18.8%). Among male patients, squamous cell carcinoma was notably common (48.0%) whereas among female patients, acinar subtype was more common. Among patients with a history of smoking, squamous cell carcinoma emerged as the most predominant subtype (50.0%). Molecular mutation analysis was carried out among 97 study participants, among patients aged 50 years or less, ALK mutation was the most common subtype, in the age group of 51 to 60 years and 61 to 70 years, EGFR mutation was the most common subtype and KRAS mutations are more prevalent among patients over 70 years (60.0%). Among females, EGFR mutations are most prevalent (68.8%), and non-smokers exhibited a higher prevalence of EGFR mutations (65.1%). 
Conclusion: Emphasis needs to be given for combining histopathological and molecular analysis in NSCLC diagnosis, personalized treatment strategies, which can lead to improved outcomes.