Lung cancer is the uncontrolled growth of abnormal cells that start off in one or both lungs; usually in the cells that line the air passages. The abnormal cells don’t develop into healthy lung tissue, they divide rapidly and form tumors.
As tumors start to become large and more numerous, they undermine the lung’s ability to help provide oxygen to the bloodstream. Tumors that remain in one place and don’t appear to spread are known as “benign tumors”.
Malignant tumors, the dangerous one, spread to other parts of the body either through the bloodstream or the lymphatic system. Metastasis refers to cancer spreading beyond its site of origin to the other parts of the body. When cancer spreads it’s much harder to treat successfully.
Primary lung cancer originated in the lungs, while secondary lung cancer will start somewhere else in the body, metastasizes and reaches the lungs. They are considered different types of cancers and are not treated in the same way.
