Lung cancer is the leading cause of cancer death in the United States. More than four in five patients die within five years of being diagnosed with the disease. More people die of long cancer than colon, prostate, ovarian and breast cancers combined. In addition to the deleterious effects of the cancer itself, lung cancer effects the ability to breathe, and leads to other respiratory illnesses. Complications include shortness of breath, coughing up blood, and dangerous fluid accumulation in the chest cavity, which in turn often leads to pneumonia.
Cigarette smoke is the leading preventable cause of lung cancer, meaning that you can significantly reduce your risk by not smoking—or quitting if you already smoke—and avoiding secondhand smoke. Eating a healthy diet and drinking in moderation, if at all, will also help. Other risk factors include exposure to pollutants such as asbestos, arsenic, particulate chromium, and nickel, or to radon gas in areas near uranium deposits. Susceptibility to lung cancer also has a genetic component, meaning someone with a family history of the condition is more prone to have it develop.
Treatment for lung cancer is most effective in the very early stages. If the disease is diagnosed, or treatment begun, too late, it may not be possible to do more than palliative care. Surgery, for example, is generally not recommended past stage II for non-small-cell lung cancer, and rarely even performed in the first stage of the far more common small-cell type. More commonly, lung cancer is treated with chemotherapy and radiotherapy to try to shrink the tumor.
More recently, an advanced type of radiation treatment has been developed that uses a beam of protons to deliver radiation directly to the tumor. Called proton therapy, it helps to overcome one of the major difficulties of radiation therapy. The placement of the lungs in the body makes targeting the radiation difficult, with a high risk of delivering it to healthy organs nearby. The narrow proton beam greatly reduces this risk, making it possible to attack the tumor without getting unaffected tissue in the process.