Lung cancer is a disease of uncontrolled cell growth

Lung cancer is a disease of uncontrolled cell growth in tissues of the lung, and is caused by smoking tobacco or secondary smoking. Air pollution, asbestos and various genetic factors increase the risks of lung cancer.

Treatment varies depending on whether the cancer is non- small cell lung carcinoma, which is usually treated with surgery, or a small cell lung carcinoma which responds better to chemotherapy and radiation. This is because small cell lung cancer has usually spread beyond the lung when it is diagnosed and so it is not possible to remove it all with surgery.

If investigations confirm lung cancer, a CT or PET scan is used to determine whether the disease is localized and will respond to surgery or whether it has spread and cannot be cured surgically. Blood tests and spirometry (lung function testing) are also necessary to assess whether the patient is well enough to be operated on. If spirometry reveals poor respiratory then surgery may not be recommended.
Surgery itself has an operative death rate of about 4.4%, depending on the patient's lung function and other risk factors. The type of surgery available will depend on the size of the cancer and its position within the lung. Lobectomy is the removal of one lobe of the lung and will be recommended if the cancer is just in one part of one lung. It is the most common type of operation for lung cancer. Bilobectomy is the removal of two lobes of the lung.

Removing the whole lung is called a pneumonectomy, and is recommended if the tumor is in the central area of the lung and has spread to the lobes on the left and right of the lung. (People can breathe properly with just one lung.)

Chemotherapy is used to treat small cell lung cancer when the cancer has spread beyond the lung. Chemotherapy drugs circulate in the bloodstream and can reach cancer cells wherever they are in the body. So it can treat cells that have broken away from the lung tumour and spread to other parts of the body even if they are too small to see on scans. This 'microscopic spread' often happens even in the early stages of small cell lung cancer.

A drug called pemetrexed is used to treat advanced non-small cell lung cancer and is given along with cisplatin as a first treatment to sufferers. Medical professionals also recommend it for people with adenocarcinoma or large cell cancer of the lung whose cancer is locally advanced or has spread to another part of the body.