Definition of Lung cancer - small cell:

Small cell lung cancer (SCLC) is a fast-growing type of lung cancer. It spreads much more quickly than non-small cell lung cancer.

There are three different types of small cell lung cancer:

• Small cell carcinoma (oat cell cancer)
• Mixed small cell/large cell carcinoma
• Combined small cell carcinoma

Most small cell lung cancers are the oat cell type.

Causes, incidence, and risk factors:

About 15% of all lung cancer cases are small cell lung cancer. Small cell lung cancer is slightly more common in men than women.

Almost all cases of SCLC are due to cigarette smoking. SCLC is rare in those who have never smoked.

SCLC is the most aggressive form of lung cancer. It usually starts in the breathing tubes (bronchi) in the center of the chest. Although the cancer cells are small, they grow very quickly and create large tumors. These tumors often spread rapidly (metastasize) to other parts of the body, including the brain, liver, and bone.