What Are the Stages of Lung Cancer?

Medically Reviewed by Paul Boyce, MD on March 08, 2024
3 min read

It’s important to know the stage of your lung cancer. It tells you:

  • Where a tumor or cancer cells are located in your lungs
  • How large your tumor is now
  • If your cancer’s in one spot or has spread


There are two main types of lung cancer: small cell and non-small cell. Each is staged differently.

Knowing the stage helps your doctor choose the right treatments for you. It may also help them gauge your chances of success with that treatment.

One thing your lung cancer stage can’t tell you is how long you’ll live.

Lung cancer staging often uses the letters T, N, and M:

  • T stands for your tumor’s size and where it’s located in your lungs or body.
  • N stands for node involvement. This means whether or not your cancer has spread to your lymph nodes near your lungs.
  • M stands for metastasis. This means whether or not your cancer has spread. Lung cancer can spread to your other lung or your liver, bones, brain, kidneys, adrenal glands, or other parts of your body.

Your doctor can stage your tumor with these letters, and then be more specific with the numbers 0-4.

They’ll measure the size of your tumor in centimeters to give it a number. The higher the number, the more your tumor has grown or spread.

They might also use X as a number. This means the tumor can’t be measured or it’s unclear how far it has spread.

If your doctor says your lung cancer is “unresectable,” that means that surgeons cannot remove it.

If you have this type of cancer, your doctor may use the TNM system. Then they’ll put your cancer into one of these two main stages:

  • Limited stage. It’s in just one lung and possibly nearby lymph nodes. It hasn’t spread to both lungs or past your lungs.
  • Extensive stage. Your tumor has spread to other areas of your lungs and chest. It may have spread to the fluid around your lungs (called the pleura) or other organs like your brain.

Non-small-cell lung cancer (NSCLC) is a more common type of lung cancer than small cell.

One way to describe NSCLC is by its clinical or pathologic stage. Your doctor might use imaging scans to take pictures of the inside of your body to see what clinical stage the cancer is. In order to confirm the diagnosis, they may do a biopsy, in which they take a small piece of tissue from the tumor and look at it under a microscope.

If you have cancer surgery, your doctor can look at your tumor and see your cancer’s pathologic stage. This tells your doctor how far the cancer has grown or spread.

The most common way to stage your NSCLC tumor is by using the TNM system with the numbers X, 0, 1, 2, 3, or 4 after each letter.

Number and letter combinations describe:

  • Your tumor’s width measured in centimeters, or if it’s too tiny to be measured at all
  • Where your tumor is located in your lung
  • If there’s more than one tumor in the same lung
  • If your airways are partly blocked or clogged enough to cause a lung collapse or pneumonia
  • If the tumor has spread to your lymph nodes or other organs

Doctors may also use general stages for NSCLC. Yours may use the TNM system and numbers to stage your cancer in each of these:

  • Occult stage: Cancer cells can be picked up in the mucus you cough up. Your tumor can’t be seen on imaging scans or a biopsy. It’s also called hidden cancer.
  • Stage 0: Your tumor is very small. Cancer cells haven’t spread into your deeper lung tissues or outside your lungs.
  • Stage I (“stage 1”): Cancer is in your lung tissues but not your lymph nodes.
  • Stage II (“stage 2”): The disease may have spread to your lymph nodes near your lungs.
  • Stage III (“stage 3”): It has spread further into your lymph nodes and the middle of your chest.
  • Stage IV (“stage 4”): Cancer has spread widely around your body. It may have spread to your brain, bones, or liver.