Non-small cell lung cancer (NSCLC)

What is non–small cell lung cancer (NSCLC)?

About 80 to 85 percent of all lung cancers are non–small cell lung cancers (NSCLC), which typically spread more slowly than small cell lung cancer.

Each subtype of NSCLC begins to grow in a different type of cell in the lungs. The most common subtypes of NSCLC are:


The most common type of NSCLC, often spreads more slowly than other types, and starts in cells that produce mucus, in outer areas of the lungs

Squamous cell carcinoma (epidermoid carcinoma)

Forms in the lining of the airways (brochial tubes); squamous cells are flatter in shape than other cells in the body

Large cell (undifferentiated) carcinomas

Can occur in any part of the lung and tends to spread more quickly than other NSCLC types

Other types

There are other subtypes of NSCLC that are rare, such as carcinoid tumor, pleomorphic, salivary gland cancer, adenosquamous, sarcomatoid, and unclassified carcinomas.

What are the signs of lung cancer?

Many people with lung cancer may not notice symptoms until it has progressed past the early stages. But signs or symptoms of lung cancer may include:

  • Persistent or worsening cough
  • Difficulty breathing
  • Chest pain
  • Coughing up phlegm or blood
  • Hoarse voice or change in voice
  • Fatigue
  • Weight loss or loss of appetite

If lung cancer has spread to distant organs, symptoms in later stages may include those listed above, as well as:

  • Difficulty swallowing
  • If spread to the bone or spine: back or bone pain
  • If spread to the spine: loss of bowel or bladder control
  • If spread to the brain: headache, blurred vision, nausea, or other neurologic effects
  • If spread to the liver: skin or eyes appearing slightly yellow (jaundice)
  • If spread to the skin or lymph nodes: lumps on the body

Common places where lung cancer spreads include the bone, abdomen, and brain. Talk to your doctor if you have any of these symptoms.

Can I get screened for lung cancer?

Although early detection is a challenge, talk to your doctor about getting screened for lung cancer if you have any of the risk factors.

Screening involves a CT scan of the chest. CT scans will show nodules or dense spots in the lung tissue, but most of these are not cancerous. If CT scans show a nodule that is growing or shaped like a cancer, then you may undergo treatment such as surgery.

Talk to your doctor about the benefits and risks of getting screened.

Risk factors: what causes lung cancer?


The majority of lung cancers are believed to be caused by smoking. If you have smoked for 30 years, 1 pack per day or more, or if it has been less than 15 years since you quit, then you are considered to be at high risk for lung cancer. If you quit smoking more than 15 years ago, your risk has gone down. Regular exposure to secondhand smoke, particularly in enclosed areas, also increases risk.

Radon in your home

Radon is a naturally occurring radioactive gas that can cause lung cancer. The state of Iowa has one of the highest concentrations of indoor radon in the nation. Learn about radon and lung cancer, and what you can do to keep your family safe.

Exposure to:

  • Asbestos
  • Arsenic in drinking water
  • Radiation
  • Dusts from metal working

Family history

If you have a first degree relative who has had lung cancer, you are at higher risk.


55 years and older (with other risk factors present)

How is lung cancer diagnosed and staged?

A CT scan, a fiberoptic exam, and biopsy of the lung are needed to confirm a diagnosis. Chest CT scan imaging, along with PET scanning, is typically used for finding tumors and determining the lung cancer stage.

The lung cancer team will determine the stage of a person's lung cancer by the TNM factors:

  1. Tumor: Describes how big the main tumor is and where it has spread
    • Called the "T factor" or "Tumor factor"
    • Given a value of T1 through T4, T4 being the most severe
  2. Node: Indicates if the tumor has spread to the lymph nodes
    • Given a value of N1 or N2 if the tumor is contained to the lymph nodes on the same side of the chest as the main tumor
    • N3 if it has spread to the lymph nodes in the other side of the chest
  3. Metastasis: Whether or not the tumor has spread (metastasized) into a new place in the body
    • Given a value of M0 if it hasn't spread
    • M1a if it has spread to the other lung or fluid around the lung or heart
    • M1b if it has spread to other organs or distant lymph nodes

These three factors combined are then used to determine the overall lung cancer stage I, II, III, or IV. Some stages may be sub-divided into A and B. The lower the stage, the better the life expectancy will be. A higher stage indicates a more severe and widespread cancer.

What are lymph nodes?

Lymph nodes are bean shaped structures connected to lymph vessels. Lymph vessels carry excess fluid from the body's tissues back into the blood stream. Lymph nodes filter harmful bacteria, fungi, and viruses in the body's lymph fluids. White blood cells and antibodies in the lymph nodes can kill these invaders, which can cause disease.

Cancer cells can break from a tumor and get into the lymph fluids, where they can get stuck in lymph nodes and start to grow.

How is non–small cell lung cancer (NSCLC) treated?

Treatment plans for NSCLC may include a combination of the following.


Drugs given to kill cancer cells, given through injections or in pill form

Radiation therapy

Radiation therapy makes it possible to deliver high-dose radiation to targeted areas of the patient's body. With stereotactic radiosurgery, radiation treatment is delivered to within tenths of a millimeter rather than the traditional three to five millimeters.

4D gated radiation therapy targets a tumor in the lungs as it moves in pace with breathing, resulting in less damage to the surrounding healthy tissue.


Our cancer surgeons have pioneered the use of minimally invasive surgical techniques to treat lung cancer, which means faster recovery after surgery. Surgery is more commonly used in non–small cell than in small cell lung cancer to remove tumors.

Molecular genetic testing

In patients with NSCLC, we will look for specific genetic mutations (changes in DNA) in the cancer cells. If found, these mutations help us predict whether the patient's tumor will respond to a specific type of treatment. Clinical trials have also shown that these DNA changes are linked to longer survival and better quality of life when compared with patients who received only chemotherapy as an initial treatment.

Clinical trials

Clinical trials are research studies that test out the latest treatments and drugs that are not yet available to the wider public. They may improve your quality of life or increase your chances of survival. A promising clinical trial for stage IV non–small cell lung cancer is currently underway at the University of Iowa. It is testing high doses of Vitamin C, injected directly into the blood stream, as a cancer therapy in conjunction with chemotherapy.

See a full list and learn more about clinical trials at Holden Comprehensive Cancer Center at the University of Iowa. Talk to your doctor to see if you qualify for a clinical trial.

What are my chances of survival?

Factors that affect survival from lung cancer include:

  • Stage of the cancer when it is found
  • Type of lung cancer
  • Age
  • Gender: Men are more likely to be diagnosed and die from lung cancer than women.
  • Overall health
  • In some cases, the type(s) of treatment used
  • In some cases, the presence of a certain genetic mutation may improve chances

Lung cancer causes more cancer deaths in the U.S. than any other type of cancer. Statistically, the chances of surviving at least five years after diagnosis is 18 percent for all types of lung cancer and 21 percent specifically for NSCLC. However, if it is found before it spreads outside the lungs, the five-year survival rate increases to 54 percent for all types of lung cancer. (Sources: American Lung Association and American Society of Clinical Oncology)

How can I prevent lung cancer?

You can help lower your risk of developing lung cancer with the following:

  • Don’t smoke and avoid secondhand smoke. If you are a smoker, seek help to quit.
  • Get your home tested for radon gas. If needed, mitigate your home to lower the levels in your home.
  • Minimize your exposure to workplace toxins such as asbestos.
  • Stay physically active: According to the NCI, regular physical activity reduces lung cancer risk by 20 percent.

Learn more

Last reviewed: 
February 2016

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