Lung Cancer - Small Cell: Introduction

Approved by the Cancer.Net Editorial Board, 01/2021

ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Small Cell Lung Cancer. Use the menu to see other pages. Think of that menu as a roadmap for this entire guide.

Lung cancer affects more than 200,000 Americans each year. About 10% to 15% of people with lung cancer have a type called small cell lung cancer.

Although cigarette smoking is the main cause of lung cancer, anyone can develop the disease. Lung cancer is treatable, no matter the size, location, whether the cancer has spread, and how far it has spread.

Because it is associated with smoking, people with lung cancer may worry that they will not receive as much support or help from the people around them. The truth is that most smokers do not develop lung cancer, and not all people diagnosed with lung cancer smoke. Lung cancer is a disease that can affect anyone. In fact, most people who get lung cancer today have either stopped smoking years earlier or never smoked.

About the lungs

The lungs absorb the oxygen from the air we breathe. The lungs bring oxygen to the bloodstream, where it travels to other parts of the body. As the body's cells use oxygen, they release carbon dioxide. The bloodstream carries carbon dioxide back to the lungs and it leaves the body when a person exhales.

The lungs contain many different types of cells. Most cells in the lung are epithelial cells. Epithelial cells line the airways and make mucus, which lubricates and protects the lung. The lung also contains nerve cells, hormone-producing cells, blood cells, and structural or supporting cells.

About small cell lung cancer

There are 2 main classifications of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). There are different treatments for each type of lung cancer. This guide provides information on SCLC. Learn more about NSCLC in a different guide. This website also offers a separate guide on neuroendocrine tumors of the lung.

SCLC begins when healthy cells in the lung change and grow out of control, forming a mass called a tumor, a lesion, or a nodule. SCLC begins in the nerve cells or hormone-producing cells of the lung. The term "small cell" refers to the size and shape of the cancer cells as seen under a microscope.

When a cancerous lung tumor grows, it can shed cancer cells. These cells can be carried away in blood or float away in the fluid, called lymph, that surrounds lung tissue. Lymph flows through tubes called lymphatic vessels that drain into lymph nodes.

Lymph nodes are small, bean-shaped organs that help fight infection. They are located in the lungs, the center of the chest, and elsewhere in the body. The natural flow of lymph out of the lungs is toward the center of the chest, which explains why SCLC often spreads there first. When a cancer cell moves into a lymph node or to a distant part of the body through the bloodstream, it is called metastasis. SCLC often spreads quickly and many people are diagnosed after SCLC has already spread to other parts of the body.

Looking for More of an Introduction?

If you would like more of an introduction, explore these related items. Please note that these links will take you to other sections on Cancer.Net:

The next section in this guide is Statistics. It helps explain the number of people who are diagnosed with SCLC and general survival rates. Use the menu to choose a different section to read in this guide.