Small cell lung cancer (oat cell) accounts for roughly 20% of lung cancers. Known for its rapid growth and spread to other areas of the body, most individuals do not have symptoms until shortly before diagnosis.
Small cell lung cancer, unlike non-small cell lung cancer, is classified into only 2 stages, limited and extensive. With limited small cell cancer, the tumor is found on only one side of the chest. At least 60 to 70% of tumors are extensive, having spread to other regions of the body at the time of diagnosis.
Although less than 5% of patients have a tumor that can be removed surgically, small cell lung cancer does respond well to chemotherapy and radiation therapy. Sadly, despite treatment, overall survival is less than 20%.
National Cancer Institute. General Information on Small Cell Lung Cancer. Updated 02/13/09. http://www.cancer.gov/CANCERTOPICS/PDQ/TREATMENT/SMALL-CELL-LUNG/PATIENT.