Stage I (Early-Stage) Lung Cancer

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

Stage I lung cancer is the second-earliest stage of the disease. It means that abnormal cells in your airways have turned into cancer. But the tumor is only in your lungs and hasn't spread to your lymph nodes.

Stage I is also called early-stage lung cancer. It often can be cured, and most people can expect to live 5 years or longer.

Almost 9 out of 10 people with lung cancer have non-small-cell lung cancer (NSCLC). A rarer and more aggressive type is called small-cell lung cancer. The numbered stages are used more often with NSCLC.

Your doctor will figure out the stage of your cancer using three key criteria called TNM:

Tumor (T). How big and where is the tumor?

Nodes (N). Is the cancer in nearby lymph nodes?

Metastasis (M). How far has the cancer spread from its original spot?

Doctors divide stage I NSCLC into two main subtypes: IA and IB. This helps them tell how serious your cancer is and decide on the best treatment.

Stage IA. Your tumor is only inside your lung and is not larger than 3 centimeters. That's about the size of a walnut. This stage is broken down into two substages based on the size of the tumor:

Stage IA1

  • The cancer is a type of NSCLC called adenocarcinoma.
  • The tumor is no larger than 3 centimeters at its widest part.
  • It has grown no more than half a centimeter into your deeper lung tissue.
  • It hasn't spread to nearby lymph nodes or to distant parts of your body.

or the cancer is not adenocarcinoma, but

  • The tumor is no larger than 1 centimeter at its widest part.
  • It hasn't spread into:
    • The membranes around your lungs (pleura) or the main branches of your airways
    • Nearby lymph nodes or to other distant parts of your body

Stage IA2

  • The tumor is between 1 and 2 centimeters at its widest part.
  • It hasn't spread into:
    • The membranes around your lungs (pleura)
    • The main branches of your airways
    • Close lymph nodes or distant parts of your body

Stage IA3

  • The tumor is between 2 and 3 centimeters at its widest part.
  • It hasn't spread into:
    • The membranes around your lungs
    • The main branches of your airways
    • Nearby lymph nodes or distant parts of your body

Stage IB

  • Your cancer hasn't spread to your lymph nodes.
  • Your tumor is larger than 3 centimeters but not more than 4 centimeters.


  • Your main tumor can be any size up to 4 centimeters, and at least one of the following is true:
    • Your tumor is in your main airway (the bronchus) but not within 2 centimeters of the carina—the place where your windpipe splits to the left and right.
    • Your cancer has spread to the membrane covering the surface of your lung.
    • Your lung has collapsed or is inflamed (pneumonitis).

You may have early-stage lung cancer and not know it. Or you may notice some common stage I lung cancer symptoms, including:

  • A new cough that lasts 3 weeks or more
  • A cough that gets worse
  • Coughing up blood or blood-stained mucus
  • Pain in your rib, shoulder, or chest
  • Pain or ache when you breathe or cough
  • Hoarseness
  • Tiredness or lack of energy
  • Loss of appetite
  • Weight loss
  • Infections like pneumonia or bronchitis that don't get better or come back
  • Lingering shortness of breath
  • Trouble swallowing

It's important to see your doctor about any symptoms. Your chances of beating lung cancer are directly tied to how early you catch it.

Sometimes, stage I lung cancer is discovered through routine tests. Or your doctor may have reasons to think you have it. If so, you may get such tests as:

X-rays and imaging scans. X-rays may show a suspicious mass in your lung. CT scans can detect smaller tumors.

Your doctor may order other tests to check the extent of your cancer. They might include:

  • PET scan
  • MRI
  • Bone scan

Biopsy. A doctor will examine a sample of your tissue under a microscope to confirm if it's cancer.

Learn more about what to do after your diagnosis.

With early intervention, stage I lung cancer can be highly curable. Usually, your doctor will want to remove the cancer with surgery. Treating lung cancer may also require chemo or radiation therapy if traces of cancer remain or are likely to stay.

Radiation therapy is an option if you can't have or don't want surgery.

The main thing that affects your treatment plan is the stage of your cancer at the time you get your diagnosis. But other things will affect your treatment as well, such as:

  • The type of cells your cancer formed in (this is your lung cancer type)
  • Where your cancer is located in the lung
  • If you have any other underlying health conditions

If you can't get surgery or decide that you don't want to have it, you can choose different treatments. These include:

  • Stereotactic ablative body radiation therapy
  • Continuous hyperfractionated accelerated radiotherapy, which is radiotherapy that's split into small doses and given to you more often, usually several times a day
  • Adjuvant chemotherapy, which is chemotherapy after radiation therapy
  • Radiofrequent ablation, a treatment that uses heat from radio waves to kill cancer cells

What is the survival rate of stage I lung cancer?

More than 65% of people with stage I lung cancer live for 5 years or more after they're diagnosed.

Can stage I lung cancer be removed?

Yes, if you are fit enough for surgery, your doctor can remove the part or your lung (or all of your lung) with cancer.

More men and women in the U.S. die of lung cancer than of any other type of cancer. But the stage I lung cancer survival rate is still good. And your chances are generally better, the lower your stage is at the time of your diagnosis.

For instance, about 92% of people with stage IA1 live for at least 5 years. That compares to 83% for those with stage IA2. The 5-year survival rate with stage IB—the far end of stage I—is 68%.

Finding out that you have even an early-stage cancer may leave you feeling shaken. Staying strong mentally and physically will help you through your treatments. Try and:

Educate yourself. Ask your doctor questions about your disease. Understand your treatment choices and what to expect from them. Knowledge will give you the confidence that you're getting the best care for your cancer.

Seek support. Reach out to friends and family for emotional, practical, and other types of help. Or talk to a mental health therapist, a medical social worker, someone from your faith institution, or other trained professionals.

Connect with others. People who have cancer may understand what you're going through in a way that's harder for others. Join a cancer support group, either in person or online. The American Cancer Society has a searchable directory of groups and programs in your area. You can look up free or reduced-fee transportation, wigs, and other support.

Learn more about everyday tips for living with lung cancer.

  • Stage I lung cancer is the second-earliest stage of this disease.
  • More than half of people who develop it will live for 5 years or more if they get treatment.
  • With proper and early diagnosis and treatment, the cure rate can be as high as 80%-90% for those whose tumor hasn't spread.
  • There are many different options for treatment based on your specific needs.