Lung cancer refers to the growth of abnormal cancer cells in either one or both of the lungs. The abnormal cancer cells do not perform the necessary functions and do not become normal lung tissue. Eventually, these abnormal cells grow into tumors, which prevent the lungs from properly oxidizing the blood. Lung cancer is the second most common cancer that afflicts both men and women, affecting men slightly more frequently then women. It accounted for 15% of all cancers in 2007, and 29% of cancer deaths. As a slow-growing cancer, lung cancer is often found in the elderly, with an average age of 69 at diagnosis.
Causes
The majority of lung cancers are caused by smoking cigarettes. Other causes include exposure to environmental factors, secondhand smoke, asbestos or radon. Lung cancer may also develop for no apparent reason, perhaps due to genetics or other external factors that are still unknown.
Symptoms
The major symptoms of lung cancer include persistent or intense coughing; back, chest or shoulder pain; hoarse voice or throat; a harsh rasping sound when breathing; coughing up phlegm or mucus that is excessive or has blood in it. While these changes may indicate other illnesses, such as bronchitis, they should be evaluated by a doctor to rule out lung cancer.
Metastatic lung cancer (lung cancer which has spread to the lymph nodes, brain, bone, liver or adrenal glands) may also cause other symptoms including fatigue, weight loss, bone or joint pain, headaches, memory loss, swelling in the face or neck, unexplained bleeding or unexplained bone fractures.
Diagnosis
There are a number of tests to diagnose lung cancer. These tests include a general physical, x-rays and/or chest exams, CT scans, PET scans, or MRIs. Specialized tests designed to diagnose lung cancer include a sputum cytology or bronchoscopy. A spuctum cytology involves the analysis of phlegm for abnormal cells; a bronchoscopy involves the use of a lighted tube that is passed through the nose into the lungs to allow the doctor to examine for tumors. If abnormal tissue is apparent within the lungs, it is removed by the bronchoscope and biopsied to test for cancer cells.
Non-Small Cell Lung Cancer
Non-small cell lung cancer is one specific type of lung cancer. Non-small cell lung cancers that have not spread beyond the lungs are treated by surgery. There are three main types of surgery: a wedge resection, in which only a small portion of the lung is removed; a lobectomy, in which an entire piece of the lung is removed; and a pneumonectomy, which removes the whole lung.
Non-small cell lung cancer often spreads to the lymph nodes, or other body parts. If the lung cancer has spread only to the lymph nodes, surgery is still possible. Chemotherapy administered prior to surgery (called neo-adjuvant chemotherapy) may be used to shrink the cancer cells to make surgery possible.
Adjuvant chemotherapy, or chemotherapy after surgery, is usually recommended for all patients with non-small cell lung cancer to ensure that any cancer cells that linger after the surgery are removed.
Small Cell Lung Cancer
Small cell lung cancer is typically considered to be a more dangerous form of lung cancer. Patients with small cell lung cancer are treated with a combination of chemotherapy and radiation. New drugs, called signal transduction drugs, are being tested at Sloan Kettering in 2009. These drugs block the signals that help cancer cells to grow, thrive and spread. Antifolate drugs are also being used to block the cancer cells access to folic acid, which is necessary for the cancer cells to grow. Finally, drugs called kinase inhibitors may also be able to prevent new cancer cells from developing.
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