When cells of the lung start growing rapidly in an uncontrolled manner, the condition is called lung cancer. Cancer can affect any part of the lung and it's the leading cause of cancer deaths in both women and men in the United States, Canada, and China.
Two main types of lung cancer exist: small-cell lung cancer (SCLC, also called oat cell cancer) and non–small-cell lung cancer (NSCLC). Small-cell lung cancer accounts for approximately 20%-25% of all cases of lung cancer.
Small-cell lung cancer differs from non–small-cell lung cancer in the following ways:
Small-cell lung cancer grows rapidly.
Small-cell lung cancer spreads quickly.
Small-cell lung cancer responds well to chemotherapy (using medications to kill cancer cells) and radiation therapy (using high-dose X-rays or other high-energy rays to kill cancer cells).
Small-cell lung cancer is frequently associated with distinct paraneoplastic syndromes (a collection of symptoms that result from substances produced by the tumor).
The predominant cause of both small-cell lung cancer and non–small-cell lung cancer is tobacco smoking. However, small-cell lung cancer is more strongly linked to smoking than non–small-cell lung cancer.
Even secondhand tobacco smoke is a risk factor for lung cancer. Those living with a smoker have a 30% increase in their risk of lung cancer compared to people who are not exposed to secondhand smoke.
All types of lung cancer occur with increased frequency in people who mine uranium, but small-cell lung cancer is most common. The prevalence is increased further in persons who smoke.
Exposure to radon (an inert gas that develops from the decay of uranium) has been reported to cause small-cell lung cancer.
Exposure to asbestos greatly increases the risk of lung cancer. A combination of asbestos exposure and cigarette smoking increases the risk even further.
Symptoms of Small-Cell Lung Cancer
Persons with small-cell lung cancer typically have had symptoms for a relatively short time (eight to 12 weeks) before they visit their doctor.
The symptoms can result from local growth of the tumor, spread to nearby areas, distant spread, paraneoplastic syndromes, or a combination thereof.
Symptoms due to local growth of the tumor include the following:
Coughing up blood
Shortness of breath
Chest pain worsened by deep breathing
Symptoms due to spread of the cancer to nearby areas include the following:
Hoarse voice, resulting from compression of the nerve that supplies the vocal cords
Shortness of breath, resulting from compression of the nerve that supplies the muscles of the diaphragm or the lungs filling with fluid and stridor (sound produced by turbulent flow of air through a narrowed part of the respiratory tract) resulting from compression of the trachea (windpipe) and larger bronchi (airways of the lung)
Difficulty swallowing, resulting from compression of the esophagus (food pipe)
Swelling of the face and hands, resulting from compression of the superior vena cava (vein that returns deoxygenated blood from the upper body)
Symptoms due to distant cancer spread depend on the site of spread and include the following:
Spread to the brain can cause headache, blurring of vision, nausea, vomiting, weakness of any limb, mental changes, and seizures.
Spread to the vertebral column can cause back pain.
Spread to the spinal cord can cause paralysis and loss of bowel or bladder function.
Spread to the bone can cause bone pain.
Spread to the liver can cause pain in the right upper part of the abdomen.
Symptoms due to paraneoplastic syndromes include the following:
Symptoms may or may not be characteristic of a specific organ system.
Nonspecific symptoms include fatigue, loss of appetite, and weight gain or loss.
Severe muscle weakness.
Trouble with balance or walking.
Changes in mental status.
Changes in skin color, texture, and facial features.