Association of Sociodemographic Characteristics and Smoking with Various Subtypes of Lung Cancer: A Record Based Study

Introduction: Lung cancer is a major cause of cancer-related deaths in India. The occurrence of adenocarcinoma is more common than squamous cell carcinoma in many areas, even among the non-smokers. Aim: To assess whether histological types of lung cancer vary with sociodemographic factors, smoking status, and the form of smoked tobacco. Materials and Methods: This retrospective record-based study reviewed 342 lung cancer cases from May 2022 to December 2024 at a tertiary centre with 310 cases being confirmed histological subtypes. Records with missing demographic or smoking details were excluded, along with 32 Fine-Needle Aspiration Cytology (FNAC) cases that did not have subtype information. Demographic details with smoking categories, and type of smoked tobacco were collected from patient files and cross-checked. Active, passive, and non-smokers were identified from the documentation, and tobacco forms were listed. The collected data and variables were analysed with the Chi-square test, and mean age across subtypes was calculated with Analysis of Variance (ANOVA). Results: Adenocarcinoma formed the largest group (37.4%), followed by squamous cell carcinoma (33.2%), large cell carcinoma (16.1%), and small cell carcinoma (13.2%). Men included approximately 80.6% of the sample, and the mean age was 62.68 years. More than half of the patients were active or passive smokers, while 23.2% had never smoked. The distribution of histological types was similar among the genders, age, and rural or urban areas. Smoking status did not change the histological pattern (p=0.246). The type of smoked tobacco also showed no difference in subtype distribution (p=0.976). Conclusion: Adenocarcinoma is the dominant lung cancer subtype and occurs in all sociodemographic and exposure groups. Routine histologic and molecular analysis for every patient is needed to guide the treatment protocol and improve diagnostic accuracy.