The Big 3: Types of Lung Cancer

Most people talk about “lung cancer” without distinguishing the type. But lung cancers actually fall into three categories, and within each category are forms as diverse as the people battling them. Knowing the type of lung cancer you or a loved one has affects treatment options and outcomes.

Non-Small Cell Lung Cancer (NSCLC)

“Most lung cancers — up to 90 percent — are non-small cell lung cancers,” says Steven Chambers, MD of Pulmonary and Critical Care Consultants, Inc.

According to Dr. Chambers, there are three predominant forms of NSCLC. “The cells in each form differ in size, shape and chemical composition,” he says. “They are placed in this category because the treatment and prognosis are often similar.”

These three forms are:

 Adenocarcinoma. The American Cancer Society (ACS) reports that this comprises about 40 percent of all lung cancers. Adenocarcinoma is usually found in outer parts of the lung, tends to grow more slowly than other types of lung cancer, and is more likely to be discovered before it has spread outside the lung.

Adenocarcinoma occurs mainly in current or former smokers, but it is also the most common type of lung cancer found in non-smokers, according to the ACS. It is more common in women, and is more likely to occur in younger people.

 Squamous cell (epidermoid) carcinoma. These cancers begin in cells that line the inside of the airways in the lungs, and are usually found in the center of the lung next to an air tube (bronchus). They are often linked to a history of smoking, and comprise up to 30 percent of all lung cancers.

 Large cell (undifferentiated) carcinoma. This form can occur in any part of the lung and represents up to 15 percent of all lung cancers. It tends to grow and spread faster than adenocarcinoma or squamous cell carcinoma.

Knowing the type of lung cancer you or a loved one has affects treatment options and outcomes.

Small Cell Lung Cancer (SCLC)

Small cell lung cancer (SCLC) is less common than NSCLC, comprising 10 to 15 percent of all lung cancers. “They grow rapidly and usually spread to distant parts of the body before being discovered,” says Dr. Chambers. “These are almost always linked to tobacco smoking.” Small cell carcinoma is sometimes called oat cell cancer.

CarcinoidThe Big 3 - Types of Lung Cancer - In Content

Lung carcinoid tumors are very rare and tend to grow slower than other types of lung cancers. They are most commonly treated with surgery.

Outside the “Main Three”

Other types of lung cancer, including adenoid cystic carcinomas, lymphomas and sarcomas, as well as benign lung tumors, are rare. These are treated differently from the more common lung cancers.

Cancers that begin in other organs can sometimes spread to the lungs, but these are not considered “lung” cancers. Treatment for these cancers is based on where they started (for example, the breast).

Steven Chambers, MD

Steven Chambers, MD

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