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The lungs are two organs in the chest that are responsible for breathing. Lung cancer is the second most common cancer in both men and women and the leading cause of cancer-related deaths in the United States for both sexes. There are two main types of lung cancer:

Patient & Caregiver Videos

What is Non-Small Cell Lung Cancer?

In the United States, 80 to 85 percent of lung cancers are non-small cell lung cancers (NSCLC). NSCLC and small cell lung cancer (SCLC) differ in how the cells look under a microscope, their origin, how quickly they spread to other parts of the body, and how they are treated.

There are three major types of NSCLC:


  • Accounts for about 50 percent of the NSCLC cases in the United States.
  • Is the most common lung cancer diagnosed in women
  • Usually starts near the outer edges of the lungs
  • May occur in those with a history of smoking, but is the type most often found in those who never smoked 

Squamous cell carcinoma

  • Represents about 30 percent of NSCLC cases in the United States
  • Usually starts in one of the bronchi
  • Frequently spreads to regional lymph nodes and, compared to adenocarcinoma, is a bit less likely to spread beyond the chest
  • Is strongly associated with smoking 

Large cell carcinoma

  • Represents about 5 percent of NSCLC cases in the United States 
  • May start in any part of the lung 
  • Is frequently the diagnosis when other types of lung cancer have been ruled out

Risk Factors, Symptoms and Screening

Risk Factors

Research is improving our understanding of lung cancer and its causes. The following are known risk factors for disease:

  • History of Smoking – The risk of developing lung cancer is related to the total lifetime exposure to cigarette smoke. People who smoke more cigarettes or over more years have a higher risk.
  • Secondhand Smoke – People who have had regular exposure to secondhand smoke are at high risk. Exposure can come from living or working in a place where people smoke.
  • Age - Most people are older than 65 years when diagnosed with lung cancer
  • Environment - Exposure to high levels of certain natural gases and chemicals such as radon, uranium, arsenic, bischloromethyl ether, asbestos, chromium, nickel, soot, tar and other substances can cause lung cancer.
  • Family History – People with a family history of lung cancer may be at risk. It is important to tell your doctor about your family’s cancer history.

Signs and Symptoms

Some people with lung cancer may develop one or more of the following symptoms. These symptoms may also be associated with other medical conditions. If you notice the onset of these symptoms, please speak with your doctor.

  • Persistent and intense coughing or coughing blood
  • Pain in chest, shoulder or back
  • Change in color and amount of sputum
  • Shortness of breath
  • Change in voice
  • Weight loss
  • Fatigue
  • Abdominal or bone pain
  • Stroke-like symptoms (i.e. one-sided weakness)


Lung cancer screening (in the form of a CT scan) is recommended for high-risk groups and significantly reduces the risk of dying from lung cancer. The U.S. Services Task Force recommends screening for people ages 55-80 who:

  • Currently smoke
  • Previously smoked and have quit within the last 15 years
  • Have a history of more than 30 pack years (e.g. 1 pack-per day for 30 years or 2 packs per day for 15 years)

If you are considering screening for lung cancer, talk to your doctor so you have a clear understanding of the process.

Diagnosis and Staging


The first step in diagnosing lung cancer is a physical exam. A doctor will listen to your lungs and the sounds of your breathing, check for swollen lymph nodes in the neck or the region above the collarbones and feel the liver to see if it is enlarged or if any masses are present in the stomach area. The diagnosis of lung cancer can only be estblished by a biopsy.

Learn More About Diagnostic Tests for Lung Cancer


Staging is used to find out whether the cancer has spread, and if so, to which parts of the body .If your cancer spreads to the bone, visit our bone metastases page. Your doctor will recommend the treatment type and approach based on your cancer’s stage. Non-small cell lung cancer has the following stages:

Stage IA

  • The cancer is less than 3 cm, has not spread to the membranes surrounding the lungs, and does not affect any other area, including the nodes or other organs.

Stage IB 

  • The cancer has not spread to nearby lymph nodes but the tumor is between 3-5 cm 
  • OR the cancer spread to the passageway of air to the lung or the inner sac surrounding the lung (pleura).

Stage IIA

  • The tumor is no larger than 5 cm and has spread to the lymph nodes on the same side of the chest
  • OR the tumor is larger than 5 cm and less than 7 cm, with no involvement of the nearby lymph nodes.

Stage IIB 

  • The cancer is greater than 5 cm and less than 7 cm, has spread to nearby lymph nodes on the same side of the chest.
  • OR the cancer is larger than 7 cm and spread to the main bronchus and other areas but not to nearby lymph nodes.

Stage IIIA 

  • Lung cancer has spread on the same side of the chest to nearby lymph nodes in the mediastinum and in the area between the lungs.

Stage IIIB

  • The tumor can be any size and has spread to the area between the lungs, heart, trachea, esophagus, backbone or the windpipe, or there are separate tumors in a different area of the same lung.
  • OR The cancer has spread to lymph nodes in the lower neck (supraclavicular fossa) or opposite side of the mediastinum.

Stage IV 

  • Cancer has spread to opposite lung.
  • The cancer has spread to other parts of the body such as the brain, liver, adrenal glands, or bone. 
  • The cancer may be found in the fluid surrounding the lungs (pleura) and heart (pericardium).

Treatment and Side Effects

There are many possible treatments with different side effects. Be sure to ask about the side effects before you start treatment. Treatment options depending upon the stage of your lung cancer and may include the following:

Surgery: If your cancer has not spread to other tissues, your doctor may recommend surgery to remove the tumor. The following surgical procedures are used to treat lung cancer:

  • Thoracotomy – an incision is made across the chest and the ribs are spread apart so that the surgeon can remove the tumor in the lung
  • Wedge or segmental resection: removal of a small part of the lung 
  • Lobectomy: removal of an entire section (lobe) of the lung 
  • Bilobectomy: removal of two lobes of the same lung
  • Pneumonectomy: removal of an entire lung 

Chemotherapy: Chemotherapy uses drugs to destroy cancer cells anywhere in your body. It is most effective against cancer cells but has effects on healthy cells as well. There are many different drugs that have been approved for the use of NSCLC, talk to your doctor about your options.

Immunotherapy: Immunotherapy pushes the body’s immune system to work harder to fight the cancer. Immunotherapy has been successful in treating some lung cancers. Ask your doctor if immunotherapy could be right for you.

Learn More about Immunotherapy for Lung Cancer

Radiation Therapy: Radiation therapy is the use of high-energy rays to kill cancer cells. Radiation works by damaging the genetic material in cells. After radiation treatment ends, cancer cells can keep dying for days or even months. Ask about different kinds of radiation, such as photons, protons, CyberKnife, GammaKnife and others.

​Targeted Therapy: Targeted therapies destroy cancer cells with less harm to healthy cells. Targeted therapies are useful to stop one of a number of specific biological processes that may be found in your cancer to make it grow. Ask if your tumor has been tested for these to see if there are targeted therapies that might work for you.

Clinical Trials: Lung cancer treatment is a very active area of research. You or your doctor may be interested in trying a clinical trial. Clinical trials can offer the opportunity to benefit from the latest treatments or combinations of treatments while helping advance knowledge of the disease and its treatment options. Ask if a clinical trial might be right for you.

Learn More About Managing Side Effects