Cancer Staging System

What does it mean to stage cancer?

Cancer happens over time as cancerous cells multiply and grow and sometimes spread (metastasize) from where they started to other areas of your body. When healthcare providers stage cancer, they focus on cancer tumor size and location. They use that information to place cancer in a specific category, or stage, labeled with numbers and letters. Staging cancer lays the foundation for cancer treatment.

Some people who have cancer may be confused and intimidated by a system that describes their illness with a formula of letters and numbers. Healthcare providers understand why people may feel this way and will take time to explain the staging system and what it means.

What is the reason for staging cancer?

Healthcare providers stage cancer for several reasons:

• Cancer is a complicated disease. Healthcare providers take a team approach to treating cancer. Staging systems give healthcare providers shared guidelines for diagnosing cancer and a common language to share what they’ve learned.
• Cancer treatment is evolving. The staging process gives healthcare providers a shared starting point that remains the same even as treatment options change.
• Most people who have cancer want to know what to expect, including the prognosis or expected outcome. Staging cancer gives healthcare providers a way to tap other healthcare providers’ experience with specific cancer types and stages. Then, they use that experience to develop a prognosis.
• Staging cancer supports clinical trials and research that improves cancer treatment. Some clinical trials and research use information about people who have the same cancer type and stage. If people want to participate in a clinical trial, healthcare providers use cancer stages to identify potential trials for people to consider.

When would healthcare providers stage cancer?

Healthcare providers use staging systems after diagnosing cancer and throughout treatment. Examples of times your healthcare provider may use staging during your treatment:

• Clinical staging: Healthcare providers set clinical cancer stages based on information gathered when they diagnose cancer. They base a diagnosis on what they learned from physical examinations and other tests.
• Pathological staging: Healthcare providers may learn more about a specific cancer during surgery to treat the cancer. For example, healthcare providers may find signs of cancer that didn’t show up in tests done to diagnose it.
• Adjuvant therapy: Adjuvant therapy is a treatment done before or after core treatment. Healthcare providers may establish a cancer stage as a baseline before treatment to show how adjuvant treatment affected the cancer.
• Restaging: Occasionally, healthcare providers may restage or revise cancer stages when cancer treatment isn’t effective or when cancer that was successfully treated comes back.

Do providers always stage cancers?

Healthcare providers stage most cancers, including solid tumors, some forms of lymphoma and gynecological cancers. Not every cancer type has a staging system, though. For example, healthcare providers don’t use staging systems for brain cancers or forms of leukemia. Here’s information on the different cancer staging systems:

• Tumor-node-metastasis (TNM): This is the most widely used staging system. Healthcare providers use TNM to stage solid tumors like bladder, breast, colon, lung and prostate cancers.
• Lugano system: Healthcare providers may use this system to stage Hodgkin lymphoma and non-Hodgkin lymphoma. They stage cancer based on whether you have cancer in nearby or other lymph nodes, organs in your lymphatic system or areas outside of your lymphatic system.
• FIGO system: Healthcare providers may use this system to stage ovarian, cervical and cancers affecting the female reproductive system. The FIGO system is similar to the TNM system.

What is TNM staging in cancer?

Tumor-nodes-metastasis (TNM) is the most commonly used cancer staging system. Here’s information on each element in TNM staging:

• T stands for primary tumor: This is information about a cancer tumor’s size and location at the time of diagnosis. Small tumors that haven’t spread may be classified as stage I tumors. Stage II cancers are larger tumors or tumors that spread into nearby tissues. The tumor classification goes from T0 to T4.
• N stands for nodes: This indicates whether a tumor has spread to nearby lymph nodes. Cancer uses lymph nodes to move to other areas of your body. The node classification ranges from N0 to N3, but node values are different depending on the cancer type. An N0 classification means the tumor hasn’t spread to nearby lymph nodes. Healthcare providers base classification on lymph nodes’ locations and the number of lymph nodes that carry cancer.
• M stands for metastasis: Metastasis happens when a tumor has spread beyond nearby lymph nodes to other areas of your body. An MI classification means cancer has spread.

What are the four stages of cancer according to the TNM system?

Healthcare providers combine data from the TNM information to place tumors in one of four stages:

• Stage I: This stage includes smaller tumors (T1-T2) that haven’t spread to nearby lymph nodes (N) or other areas of your body (M0).
• Stage II: This stage includes larger tumors that haven’t spread to nearby lymph nodes or other areas of your body. The TNM classification is T2-T4, N0 and M0.
• Stage III: Healthcare providers use this stage for large tumors that have spread to nearby lymph nodes, but not to other areas of your body. The TNM classification is T1-T4, N1-N3 and M0.
• Stage IV: This is metastatic cancer. That means cancer has spread from the primary tumor to other areas in your body. The TNM classification is T1-T4, N1-N3 and M1.

Healthcare providers may also use different terms to describe cancer stages. Examples include:

Are cancer stages the only way healthcare providers evaluate cancer?

Healthcare providers also evaluate cancer based on the tumor’s grade. Healthcare providers set tumor grade by examining tumor cells and tissue under a microscope. They look for differences between normal cells and tissue and abnormal cells and tissue.

Cells and tissue that mostly look like normal cells and tissue are low-grade cells. Cells that look more like abnormal cells and tissue are high-grade cells. Tumor grades range from GX to G4. A GX classification means healthcare providers can’t see enough difference to set a tumor grade. A G4 classification means the cells and tissues don’t look like normal cells and are rapidly growing and multiplying.

What tests do healthcare providers do to stage cancer?

Healthcare providers stage cancer by doing physical examinations and several different tests:

• Computed tomography (CT) scan: These scans help healthcare providers identify early-stage cancers and tumor location.
• Positron emission tomography (PET) scan: Healthcare providers may use this test to see if tumors have spread to distant areas of your body.
• Endoscopy: Healthcare providers insert a thin tube into hollow organs to examine their interior for signs of cancer.
• Biopsy: Healthcare providers obtain tissue samples they can analyze for more information about cancer.
• Blood tests to identify tumor markers:Tumor markers are substances in your blood or serum that can help healthcare providers determine the number of cancer cells, tumor size or amount of cancer in your body.

What happens after healthcare providers set a cancer stage?

Healthcare providers use cancer stages to develop treatment plans. They also use cancer stage information to develop prognoses, or expected outcomes.

Is stage 4 cancer always terminal?

If you have stage IV (4) cancer, there’s cancer in several areas of your body. People who’re diagnosed with stage IV cancer don’t typically live as long as people who have cancer diagnosed in an earlier stage. That said, every cancer type is different. If you have stage IV cancer, ask your healthcare provider about your prognosis. They know your situation and are your best resource for information.

Does my cancer stage change?

No, the formal stage of a cancer stays the same even if the cancer spreads or otherwise changes. Healthcare providers update cancer stages by adding information about the cancer as it changes.

A note from Cleveland Clinic

If you have cancer, you may be confused or overwhelmed when healthcare providers describe your disease using a formula of letters and numbers. But there’s more to a cancer stage than a formulaic name. Healthcare providers use cancer staging systems and terms to create treatment plans, collaborate with others and develop a prognosis so you know what to expect. Talk to your healthcare provider if you want more information about your cancer stage information. They understand that it’s not always easy to grasp medical terms, especially if you hear them as you’re still coming to terms with having cancer. Ask your healthcare provider to explain how the cancer staging system works and what your cancer stage means.