Lung cancer strikes down more people---men and women---globally than any other type of cancer. In the United States alone, one out of every 14 individuals will develop this disease. Of those, less than one-half will survive the first year, and less than 25 percent have a 5-year survival rate. In recent years, it has taken more victims than prostate, breast and colorectal cancers combined.
History
A major disadvantage of lung cancer is that it rarely is detected in its early stages. Nearly 25 percent of sufferers are symptom-free at the time of their diagnosis. Lung cancer often is discovered by "accident" when a chest X-ray or CT (computed tomography) scan is taken for something else. In those cases, the cancer appears as a single, small tumor, also known as a "coin lesion," since the circular tumor resembles a coin.
Primary Lung Cancer
Most individuals develop symptoms as a result of the direct impact of a "primary" growth or metastatic growths located in other areas of the body. As the cancer progresses, it invades tissue in and surrounding the lungs. Signs that may be indicative of primary lung cancer include a new, persistent or blood-producing cough; blunt, aching and constant pain in the chest; shortness of breath or panting; scratchy voice; or recurring bouts of respiratory ailments, such as bronchitis or pneumonia.
Metastatic Lung Cancer
Symptoms are different if the lung cancer has metastasized to other parts of the body. Lung cancer that has spread to the liver or adrenal glands generally has no symptoms when a diagnosis is made. When the brain is affected, individuals may have vision problems or seizures, or they may lose strength on one side of their body. Metastatic lung cancer in the bones typically causes discomfort in the vertebrae (backbone), ribs or thighs. If the cancer has violated the nerves, sufferers could experience pain in the shoulder that radiates along the outer portion of the arm, or the vocal cords could shut down. Problems swallowing could result if the cancer invades the esophagus, and if a large airway becomes blocked, part of the lung is susceptible to collapse, and an infection may develop.
Other Common Symptoms
Signs and symptoms of lung cancer may take some time to develop and not surface until the disease is in the advanced stages. Other common signs include decreased appetite or sudden weight loss, lethargy, headaches, memory loss, bleeding or clotting.
Risk Factors
Although cigarette smoking accounts for nearly 90 percent of all lung cancers, there are other risk factors to consider. Secondhand---or "passive"---smoke is responsible for 3,000 lung cancer deaths in the United States annually. Asbestos and radon exposure over an extended period of time also increases the chances of developing the disease. In some cases, the individual has a genetic predisposition to cancer.
