Lung cancer, the most common cancer in the world, the Merck Manual states, has a poor prognosis, with 15 percent of patients surviving five years even with treatment. Smoking causes 85 percent of cases of lung cancer, according to the Merck Manual. Lung cancer is classified as small cell or non-small cell; lung cancer metastasizes, or spreads beyond the lungs, in 60 percent of cases of small cell and 40 percent of non-small cell cases by the time of diagnosis. Treatment depends the stage of disease at the time of diagnosis.
Surgery
Non-small cell cancer is classified from stage I through stage IV, while small cell cancer is differentiated as limited and extensive. Stage I, II and sometimes stage III non-small cell tumors are treated with surgery, MayoClinic.com states. Surgery cures 50 percent to 75 percent of people with stage I disease and 35 percent to 55 percent of those with stage II disease, according to Merck. Surgery can remove a small portion of the lung, a single lobe or the entire lung. Patients with cancers that can be surgically treated, called resectable tumors, have the best prognosis, the National Cancer Institute states. Small-cell cancers, very aggressive tumors, are rarely treated surgically, because they've usually spread by the time they're diagnosed.
Chemotherapy
Chemotherapy, administration of medications that kill cancer cells, can be used after surgery or as a primary treatment. Chemotherapy with thoracic radiation therapy improves the response in small cell cancer by around 5 percent, the National Cancer Institute reports. Chemotherapy medications are often given in combination and may be given intravenously or, in some cases, orally.
Radiation
Radiation therapy directs high-energy beams at tumors in the lungs or places it near the tumors in catheters, needles or seeds, a procedure known as brachytherapy. Radiation is used in limited small cell lung cancer and stage II and III non-small cell cancers. Exposing large areas of the lung to radiation at one time may cause radiation pneumonitis up to three months after radiation.
Other Treatments
Bevacizumab, also called Avastin, a vascular endothelial growth factor inhibitor, often given along with chemotherapy, interrupts the development of new blood vessels that feed non-small cell lung cancer, MayoClinic.com explains. Erlotinib, known as Tarceva, another drug that blocks tumor growth is prescribed for non-small cell cancers that haven't responded to chemotherapy. Radiofrequency ablation, which uses high frequency electrical current to destroy tumor cells, may be used for small early-stage tumors or for tumors that recur after radiation, according to Merck.
