Background:According to estimates, the global cancer burden increased to 18.1 million new cases and 9.6 million deaths in 2018..Lung cancer is the most common cancer-related cause of death in both men and women. In most Western and Asian countries, adenocarcinoma has now surpassed squamous cell carcinoma. In India, however, the clinical and pathological picture of lung cancer varies greatly.Aim: The goal of this study is to look at the clinicopathological and immunohistochemical profiles of 100 patients of lung cancer in a North Indian tertiary care occupational centre.Material and methods:This is a retrospective study of lung carcinoma patients who were diagnosed with biopsy-proven lung cancer in the previous four years (between May 2016 and May 2020). Patients were diagnosed using the WHO classification of lung malignancies 2015as nonsmall cell lung carcinoma (SCC), adenocarcinoma, nonsmall cell lungcarcinoma not otherwise defined [NSCLCNOS]), small cell lung carcinoma, and others based on morphology in H&E stained sections. In all cases, immunohistochemistry (IHC) was used to help the sub-classification. In some cases, IHC was used to detect EGFR and ALK rearrangements.Result:The average age of the patients in our study was 61.04 years old (12 percent were under 50 years old and 6% were under/equal to 45 years old). Smokers made up 54 percent of all lung cancer patients. COPD was seen in 43.8 percent of lung cancer patients, and it was often linked to smoking. 4.5 percent of the patients had a history of ATT ingestion, while 36.6 percent of the patients had no relevant medical history. Cough (26%) was the most common symptom, followed by chest pain (23%), and shortness of breath (28%) in almost equal percentages and were most frequently occurring together.Squamous cell carcinoma (38 percent), adenocarcinoma (27 percent), non-small cell carcinoma-not otherwise specified(NOS) (5 percent), adenosquamous carcinoma (3 percent), and small cell carcinoma (17 percent) were the subtypes with the highest percentages histologically, with immunohistochemical confirmation.Conclusion:Along with age, radon exposure, environmental pollution, occupational exposures, gender, race, pre-existing lung disease, and genetic factors, cigarette smoking is the leading cause of lung cancer and lung cancer in the occupational category
