Lung cancer basically divided into Small cell lung cancer (SCLC) and non small cell lung cancer (NSCLC).NSCLC is most predominant about 85% lung cancer cause due to NSCLC. The NSCLC is further divided into adenocarcenoma,squamous cell carcenoma,and large cell lung carcenoma. The SCLC metastasizes affects other organs such asliver,bones,brain,adrenal glands apart from lungs.Squamous cell carcenoma drives from squamous cells that line the respiratory tract,adenocarcenoma drives from the cells that lines the alveoli (air sacs).The large cell lung carcenoma arises from the cells that lines of the lungs. Cancer causes due to genetic mutation.This mutations are called somatic mutations. Somatic mutations in TP53,EGFR and KRAS is more common in lung cancers. TP53 instruct to make a protein p53 found in nucleus of cells all over the body. The EGFR and KRAS genes are instruct to make a protein which is present in the cell membrane.
Mutations on somatic cells will disturbs the cell cycle and induce cell proliferation which lately results in tumour formation. The mutated P53, EGFR and KRAS genes causes lung cancer. P53 has direct contact with DNA acts a suppressor of tumour and guards the cell divisions. When these genes are mutated they induce expression of different genes (especially P53) leading to lung cancer.
