Interior of the cecum and lower end of ascending colon with the ileocecal valve labeled as colic valve. Endoscopic image of cecum with arrow pointing to ileocecal valve in foreground.
Lung cancer is a malignant tumour that starts in the cells of the lung. Malignant means that it can spread, or metastasize, to other parts of the body. When cancer starts in lung cells, it is called primary lung cancer. The lung is part of the respiratory system. You use your lungs when you breathe.
What is Lung Cancer? Lung cancer arises when a series of mutations in normal lung cells cause them to become abnormal and grow out of control. These changes can take place anywhere from the bronchus (the windpipe), down to the small air sacs in the periphery of the lungs (the alveoli) where oxygen exchange takes place. It's important to note that lung cancer is a multifactorial.