Lung Cancer Stages and Classifications

Understanding Staging

Understanding your lung cancer stage is a major step in taking control of your health. Doctors use "staging" to describe exactly where the cancer is and how much it has grown. This helps them decide which treatments, like surgery or medicine, will work best for you.

What Are the Stages of Lung Cancer?

When doctors talk about the "stage" of lung cancer, they are describing how big the cancer is and how far it has spread in the body. Staging matters because it is the single biggest factor in deciding which treatments will work best for you. A lower number means the cancer is more contained. A higher number means it has spread further.

Non-small cell lung cancer (NSCLC), the most common type, is staged from 0 to 4. Small cell lung cancer (SCLC) uses a simpler two-stage system, which is explained below.

Stage 0 Lung Cancer

Stage 0 is also called "carcinoma in situ," which means "in place." Abnormal cells are found only in the very top layer of cells lining the airways. They have not grown into deeper lung tissue and have not spread anywhere else. Stage 0 lung cancer is rare because it causes no symptoms, but when it is found, usually during screening, it can almost always be treated successfully with surgery alone.

Stage 1 Lung Cancer

In stage 1, the cancer is a small tumor (generally 4 centimeters or less) that is only in the lung. It has not reached any lymph nodes or other parts of the body. Surgery to remove the tumor is usually the main treatment, and for many people it can be curative. Some patients also receive radiation, chemotherapy, or immunotherapy after surgery to lower the chance of the cancer returning.

Stage 2 Lung Cancer

In stage 2, the tumor is larger, or the cancer has spread to lymph nodes inside the lung or right where the airway enters the lung. It is still considered early-stage cancer. Treatment usually starts with surgery, often followed by chemotherapy or other medicines to destroy any cancer cells that may remain.

Stage 3 Lung Cancer

Stage 3 is called "locally advanced" lung cancer. The cancer has spread to lymph nodes in the middle of the chest, or the tumor has grown into nearby structures, but it has not traveled to distant parts of the body. Stage 3 is usually treated with a combination of approaches, such as chemotherapy and radiation given together, sometimes followed by surgery or immunotherapy. Treatment plans at this stage vary widely from person to person, which is why care from a multidisciplinary team is so valuable.

Stage 4 Lung Cancer

Stage 4 means the cancer has spread (metastasized) to the other lung, to the fluid around the lungs or heart, or to distant parts of the body such as the bones, liver, or brain. Stage 4 lung cancer is not usually curable, but it is treatable, and treatment has improved dramatically in the last decade. Targeted therapies, immunotherapy, and combination treatments are helping many people with stage 4 lung cancer live longer, with a better quality of life, than was possible even a few years ago. Doctors will test the cancer's genetic makeup to find the treatment most likely to work for you.

Stages of Small Cell Lung Cancer

Small cell lung cancer is usually described in two stages instead of numbers.

Limited Stage

This stage means the cancer is on one side of the chest and can be treated within a single radiation field.

Extensive stage

This stage means the cancer has spread more widely through the lungs or to other parts of the body.

Because SCLC grows quickly, treatment, most often chemotherapy combined with radiation or immunotherapy, begins as soon as possible at either stage.