Cancer is a group of diseases caused by uncontrolled cell growth, invasion and spread of cells from the site of origin or primary sites to other sites in the body. Most cancers, 85%, arise in epithelial cells and are classified as carcinomas. Lung cancer is one of the most commonly diagnosed major cancers and the common cause of cancer death. Almost all carcinomas in lung cancer are similar to those in cancer at other sites, which occur due to repeated deposition of genetic abnormalities that convert Beningn epithelium into Beningn epitheliumFactors causing lung cancerSmoking : statistics reveal that 87% of lung carcinomas occur in active smokers. Industrial risks: exposure to certain industrial hazards such as uranium, asbestos increases the risk of developing lung cancer Air pollution: pollutants such as radon, a ubiquitous radioactive gas causes lung cancer when inhaled Molecular genetics: Exposure to the above factors alters the genetic components, and ultimately leads to the neoplastic phenotype. Lung cancer is divided into two types, namely small cell carcinoma and non-small cell carcinoma. The two types have some similarities in molecular damage, while others are quite specific. The dominant oncogenes frequently implicated in lung cancer are c-MYC, KRAS, c-MET and c-KIT. And the most inactivated tumor suppressor genes are p53, RBI, p16 (INK-4a) and several loci on chromosome 3p, where many tumor genes such as FHIT, RASFFIA and other genes that have not yet been identified are present in the loci. In small cell lung carcinoma, various genes such as C-KIT(40-70%),MYCN and MYCL(20-30%),p53(90%),3P(100%),RB(90%) and BCL2(75 -90%) are mainly involved while as in non-small cell lung...... middle of paper ...... surgical intervention should be performed if the cancer does not exceed the stage N0/1. Compared to small cell carcinoma, NSLC is less sensitive to chemotherapy, but less sensitive to chemotherapy and radiotherapy. Small cell carcinoma is widely metasized at the time of diagnosis and treatment, although palliative, can significantly prolong survival. Other therapies such as laser phototherapy, cytotherapy and brachytherapy are also used. Like the rise of no. Through the identification of biomarkers, early detection of lung cancer by non-radiological means becomes possible. Biomarkers still under evaluation include markers of genetic, histological, and phenotypic changes in tissues associated with carcinogens. Most of these methods involve screening bronchial epithelia, in the form of biopsies, obtained from sputum or blood samples. The most convenient way to obtain samples is bronchoscopy..