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What Are the Stages of Lung Cancer?

Lung cancer research cartoon

There are mainly two types of lung cancer—small cell lung cancer and non-small cell lung cancer. The more common type is non-small cell lung cancer (NSCLC) which accounts for around 8 out of 10 cases. The treatment and outlook for these two types of lung cancer are different. Besides the type, there’s one other thing that plays a key role in choosing treatment for lung cancer and gauging the chances of successful treatment—the lung cancer stage. 

Lung cancer stages tell us where the tumor is located in the lungs, how big it is, and whether it has spread to lymph nodes or other parts of the body. Continue reading to learn more about how lung cancers are staged and why cancer staging is important.

Why is it important to stage lung cancer?

After a lung cancer is diagnosed and the type of lung cancer has been identified, it is then assigned a stage. There are different methods of staging lung cancers. The two main types of lung cancer—small cell lung cancer and non-small cell lung cancer are staged differently. But why is it important to stage cancer?

Lung cancer staging provides helpful information to doctors and patients. Treatment is recommended and planned based on the stage of lung cancer. The chances of successful treatment and cure are higher if lung cancer is diagnosed early before the cancer has spread. Therefore, the lung cancer stage helps to predict the most likely outcome. Knowing the stage allows doctors to make an educated guess about the chances of cure and life expectancy. However, it is worth noting that other factors, such as a person’s age and underlying health status, can affect how long they will live after a lung cancer diagnosis.

What is TNM staging? Why are lymph nodes important?

Lung cancer stages are frequently indicated with the letters T, N, M. In the TNM system of lung cancer staging, each of the letters provides some information about the cancer. 

  • T indicates the tumor size and location
  • N indicates whether the cancer has spread to the lymph nodes near the lungs
  • M indicates metastasis or spread of lung cancer to distant parts of the body, for example, the brain, bones, liver, and kidneys.

Doctors also assign numbers with these letters, usually 0-4, and may further specify the numbers with letters to provide more information about the stage of lung cancer. Lower numbers indicate smaller tumors and those that are in the nearby lymph nodes stage. Higher numbers indicate larger tumors or tumors that have grown and spread to other organs in the body. 

What are the stages of small cell lung cancer?

Small cell lung cancer (SCLC) is the less common of the two types of lung cancer. It accounts for around 15% of all cases. Although this type of cancer grows more quickly than non-small cell lung cancer, it is more responsive to chemotherapy. There are two small cell lung cancer stages:

  • Limited stage SCLC is present on only one side of the chest. It involves only one part of the lung and nearby lymph nodes.
  • Extensive stage SCLC has spread throughout, to other parts of the chest and other organs in the body.

What are the stages of non-small cell lung cancer?

Non-small cell lung cancer (NSCLC) accounts for around 85% of all lung cancers. There are various types of NSCLC, including squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. NSCLC is staged differently than small cell lung cancer.

Stage of NSCLC


Stage 1
  • Limited to one lung and has not spread to nearby lymph nodes
Stage II
  • Present in the lung and has spread to nearby lymph nodes
Stage III
  • Present in the lung and the lymph nodes in the central part of the chest. There are two subtypes of stage III non-small cell lung cancer:
    • Stage IIIA is cancer that has spread only to lymph nodes on the same side of the chest where the cancer started.
    • Stage IIIB is cancer that has spread to lymph nodes on the opposite side of the chest or the lymph nodes above the collar bone.
Stage IV
  • The most advanced stage of non-small cell lung cancer. It indicates that cancer has spread to both sides of the chest including the opposite lung, cancer cells are present in the fluid surrounding the lung, and the cancer may have spread to other areas of the body, including distant organs such as the liver, brain, and bones.


Is stage 1 lung cancer curable?

Stage I lung cancer is early-stage lung cancer that has been discovered soon after it developed. With early diagnosis and treatment, stage I lung cancer is highly curable. It can be treated and cured with surgery, chemotherapy, and radiation therapy. 

According to the American Cancer Society, the 5-year relative survival rate for localized non-small cell lung cancer (cancer that has not spread outside the lung) is 63%. This means that people with stage I NSCLC are about 63% as likely as healthy people to live for at least 5 years after the diagnosis. The 5-year survival rate for localized small cell lung cancer is 27%.

It is worth remembering that these numbers do not consider everything. For example, besides the small and non-small cell lung cancer stages, other factors like age, overall health, gene changes in the cancer cells, and response to treatment can affect the outlook.

How bad is stage 4 lung cancer?

Stage 4 is an advanced stage of lung cancer. The outlook is poorer than stage 1, stage 2, and stage 3 lung cancer. Stage 4 indicates cancer has spread to both lungs, cancer cells are present in the fluid around the lung, and the cancer has spread to distant organs such as the bones, brain, and liver. 

How long does a person have to live with stage 4 lung cancer?

The relative 5-year survival rate for people with distant stage lung cancer is 7% for non-small cell lung cancer and 3% for small cell lung cancer. This means that people with stage IV lung cancer have less than a 10% chance of being alive 5 years after the diagnosis compared to healthy people.

It is worth noting that these survival rates are based on people diagnosed and treated for lung cancer 5 years earlier. Despite the grim statistics, people with lung cancer are living better and longer lives than ever before thanks to advances in treatment options. 

Can you be cured of stage 4 lung cancer?

There is currently no cure for stage IV non-small cell lung cancer or extensive-stage small cell lung cancer. The outlook is not good, unfortunately. However, a comprehensive treatment plan can alleviate symptoms, keep a person comfortable, and prolong their life. As noted, the outlook also depends partly on the type of lung cancer (small cell vs non-small cell) and other factors such as the person’s age, health status, and response to treatment. 


  1. https://www.lungcancer.org/find_information/publications/163-lung_cancer_101/268-types_and_staging
  2. https://www.cancer.org/cancer/lung-cancer/detection-diagnosis-staging/survival-rates.html