Small cell lung cancer (SCLC) starts in certain cells that surround the bronchi called neuroendocrine cells. The bronchi are the air tubes that lead from the trachea (windpipe) to the lungs. Small cell lung cancer, also called oat cell cancer, is less common than non-small cell lung cancer. About 13 out of every 100 lung cancer cases each year are small cell lung cancer. Men are more likely than women to get small cell lung cancer.

Small cell lung cancer tends to spread quickly to other areas and to the lymph nodes in the chest. This means that when the cancer is found, it often already has begun to spread. 

Treatment for small cell lung cancer usually involves chemotherapy. In recent years, immunotherapy has become an additional treatment for some people with small cell lung cancer. It is used either alone or with chemotherapy. MSK surgeons can remove the tumor in some patients with limited-stage small cell lung cancer. It is called limited stage if it can be treated with radiation in 1 area. That usually means it is in 1 lung, or maybe only on 1 side of the chest.