There are two primary forms of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Though SCLC is less common than NSCLC, it is more aggressive and rapidly spreads (metastasizes) throughout the body. SCLC accounts for about 15 percent of all lung cancer diagnoses in the United States each year, affecting about 30,000 people.
Due to how quickly it grows and spreads, in 70 to 80 percent of SCLC cases the cancer has already metastasized to other areas in the body by the time it is diagnosed. Common sites for metastasis are the lymph nodes, liver, bones, adrenal glands and brain. When SCLC metastasizes, the cancer can cause symptoms that are not typically associated with lung cancer, including bone pain, seizures, confusion and paralysis.
Smoking tobacco is the leading risk factor for SCLC, responsible for 98 percent of all SCLC diagnoses. The best preventive strategy is not to smoke, and if you do, to quit as soon as possible.
Treatments for SCLC include chemotherapy and radiation. Because of the high rate of metastasis, surgery is rarely recommended. In very advanced cases of SCLC, treatments (including chemotherapy and radiation) can be effective in relieving symptoms and improving quality of life.
“Even though SCLC has a tendency to grow quickly, it often shrinks quickly as a response to chemotherapy, radiation therapy, or both,” said Henry Park, MD, MPH, a radiation oncologist and assistant professor of therapeutic radiology at the Yale School of Medicine. “It is important to see a medical oncologist and radiation oncologist as soon as possible after a diagnosis of SCLC so that treatment can be started right away.”