Non-Small Cell Lung Cancer: The Basics

Author: Marisa Healy, BSN, RN
Last Reviewed: May 01, 2025

Lung cancer is caused by lung cells growing out of control. As the number of cells grows, they form a tumor. There are many types of lung cancers. This article is about non-small cell lung cancer. Other types of lung cancer are small cell, mesothelioma, and carcinoid tumors.

Non-Small Cell Lung Cancer (NSCLC):

  • The most common type of lung cancer, making up 80 to 90 out of 100 cases.
  • Tends to be slower-growing than small cell lung cancer.
  • Different types are based on the cells that make up the tumor:
    • Adenocarcinoma.
    • Squamous cell carcinoma.
    • Poorly differentiated or large cell carcinoma.

Lung cancer that has spread from your lung to another part of your body is called metastatic cancer.

Risks

Smoking cigarettes (now or in the past) is the leading cause of lung cancer. Lung cancer in non-smokers has been rising in recent years. Other causes for lung cancer may be radon, radiation, asbestos, and pollution exposure.

Screening

Smokers or former heavy smokers can have a special test (CT scan) to screen for lung cancer. This test can find lung cancer sooner and may help patients live longer. Talk with your healthcare provider to see if this test is right for you.

Signs and Symptoms of Lung Cancer

The early stages of lung cancer may not cause any signs or symptoms. As the tumor grows, it can cause:

  • A cough that doesn't go away or gets worse. A cough is the most common sign. Many long-term smokers have a cough that doesn't go away. If there is a change in your cough, see your provider.
  • Chest pain.
  • A hard time breathing.
  • Wheezing.
  • Coughing up blood or bloody phlegm.
  • Your voice to be hoarse or your speech to change.
  • Pneumonia (lung infection) or bronchitis (inflamed airways) that keeps coming back.
  • Weight loss and not feeling as hungry (loss of appetite).
  • You feel tired.

Diagnosis of Lung Cancer

When your care team thinks you may have lung cancer, they will order tests. Here are some of the tests:

  • Chest x-ray.
  • CT scan (CAT scan).
  • Sputum cytology (looking at your phlegm for cancer cells).
  • A PET scan and an MRI are often done to look at other parts of your body where lung cancer can spread.

These tests are important, but a biopsy is the only way to know for sure if you have cancer. A biopsy:

  • Looks at a piece of the lung for cancer cells.
  • Is used to find out the cancer type, how normal it is (grade), and if it has spread.
  • May look at samples from your lymph nodes to check for cancer.
  • May be done using a bronchoscopy (a small camera passed down your throat into the lungs) or by surgery.

A pathology report sums up these results and is sent to your provider, often 5 to 10 days after the biopsy. This report helps plan your treatment. You can ask for a copy of your report for your records.

Staging Lung Cancer

To guide treatment, lung cancer is "staged." This stage is based on:

  • Where and how big the tumor is.
  • If there are cancer cells in your lymph nodes.
  • If there are cancer cells in other parts of your body.

Stages are from stage 0 (zero), the smallest, most confined tumors to stage IV (four), tumors that have spread to other parts of the body, also called metastatic cancer.

The stage and type of lung cancer will guide your treatment plan.

Treatment

Treatment of NSCLC may be:

  • Surgery: Used to remove as much of the cancer as possible.
  • Chemotherapy medications can kill cancer cells throughout your whole body. Most patients will have chemotherapy, either before surgery (called neoadjuvant) or after surgery (called adjuvant). Chemotherapy can also be given before, during, or after radiation therapy.
  • Radiation therapy uses high-energy X-rays to kill cancer cells. Radiation can be used with surgery, or when surgery is not an option.

This article is a basic guide to non-small cell lung cancer. Read more about your type of lung cancer and treatment:

Non-small Cell Lung Cancer: Staging and Treatment