3.2: What are the next steps if your lung nodule is cancer?

Funding for the Lung Health Hub is provided by AstraZeneca. All content is developed independently by Outcomes4Me; AstraZeneca has no influence on the content of the site.

If a lung nodule turns out to be cancerous, your care team will focus on learning more about the cancer, including how advanced it is, whether it has spread, and how best to treat it. An important part of this process is called staging, and it’s one of the most important steps in building your personalized care plan.

What is staging for lung cancer?

Staging is the process doctors use to determine how much cancer is in your body and where it’s located. Think of it as a roadmap that helps guide treatment decisions. The stage of your cancer helps your care team decide which treatments are most likely to work best for you—such as surgery, radiation therapy, targeted therapy, or immunotherapy. Depending on your lung nodule, staging and diagnosis can sometimes be done at the same time.

Types of staging

There are two main types of staging that may be used during your diagnosis and treatment journey:

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• Clinical stage: This is determined before treatment begins. It’s based on information gathered from imaging tests (like CT scans or PET scans), biopsies, and physical exams.
• Pathological stage (also called surgical stage): This is determined after surgery, when doctors can examine the tumor and nearby lymph nodes more closely under a microscope.

Sometimes, the pathological stage provides more detail than the clinical stage because doctors can see exactly how far the cancer has spread.

TNM staging for lung cancer

Doctors often use a system called TNM to describe lung cancer stages:

• T (Tumor): Describes the size and location of the main tumor in the lung.
• N (Nodes): Indicates whether the cancer has spread to nearby lymph nodes.
• M (Metastasis): Tells whether the cancer has spread to other parts of the body, such as the brain, bones, or liver.

Each letter is followed by a number that gives more details. For example, a higher number may mean a larger tumor or more lymph nodes involved.

Stages of lung cancer

Once doctors gather all this information, they assign an overall stage from stage 0 to stage IV for non-small cell lung cancer (NSCLC), which is the most common type of lung cancer:

Stage 0 (in situ): Cancer cells are only in the top layer of the lung’s lining and haven’t spread deeper into lung tissue.

Stage I: The cancer is small and confined to the lung.

• Stage IA: The tumor is 3 centimeters (a little over an inch) or smaller.
• Stage IB: The tumor is between 3 and 4 centimeters or has slightly grown into nearby structures but hasn’t reached lymph nodes.

Stage II: The cancer is larger or has spread to nearby lymph nodes.

• Stage IIA: The tumor is between 4 and 5 centimeters but has not spread to lymph nodes.
• Stage IIB: The tumor may be up to 5 centimeters and has spread to nearby lymph nodes on the same side of the chest, or it may be larger (5–7 cm) but still without lymph node spread.

Stage III: The cancer has spread more widely in the chest but not to distant parts of the body.

• Stage IIIA: The cancer has spread to lymph nodes in the center of the chest but still on the same side as the tumor.
• Stage IIIB: The cancer has spread to lymph nodes on the opposite side of the chest or above the collarbone, or the tumor has grown into nearby structures like the heart or major blood vessels.
• Stage IIIC: The cancer involves multiple lymph node areas or larger tumors that have invaded nearby organs, but still no distant metastasis.

Stage IV: The cancer has spread (metastasized) to other parts of the body, such as the brain, bones, liver, or the other lung.

Why staging matters

Staging is a critical step because it guides every treatment decision. Once your cancer is staged, your care team will use evidence-based recommendations, like the National Comprehensive Cancer Network (NCCN) Guidelines, to design the best possible treatment plan for you. 

These guidelines are updated regularly by cancer specialists who review the latest research and clinical trial data. They outline which tests, treatments, and follow-up care options are most effective for each stage and type of cancer. These guidelines help ensure that patients receive care that reflects the latest research and expert consensus.