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Prostate Cancer Stages and Classification

Last updated and reviewed on March 26, 2026.

Understanding TNM Staging and the Gleason Score

When your doctor diagnoses prostate cancer, they use two important tools to describe it:  Staging and the Gleason Score. Here is what each one means in simple terms.

TNM staging: Where is the cancer?

TNM stands for Tumor, Nodes, and Metastasis. Think of it as answering three questions:

T = Tumor: How big is the cancer, and where is it?

Doctors assign a T score between 1 and 4. This describes the size of the main tumor and if it has grown outside the prostate.

• T1: Stage 1 (Early): The cancer is very small and cannot be felt during an exam. It was likely found by accident during another procedure or through a PSA blood test.

• T2: Stage 2 (Early) The cancer can be felt but is still fully inside the prostate.

• T3: Stage 3 (Locally Advanced) The cancer has broken through the outer wall of the prostate and is starting to grow into nearby tissue.

• T4: Stage 4 (Advanced) The cancer has grown into nearby organs, such as the bladder or rectum.

N = Nodes: Has it reached the lymph nodes?

Lymph nodes are small glands that are part of your immune system. They are scattered throughout your body, including in the groin near the prostate.

• N0: The cancer has not spread to any nearby lymph nodes.

• N1: The cancer has spread to nearby lymph nodes. This means it is starting to travel beyond the prostate area.

M = Metastasis: Has the cancer spread to other parts of the body?

"Metastasis" means the cancer has traveled to a distant part of the body.

• M0: The cancer has not spread to other organs or bones.

• M1: The cancer has spread. Prostate cancer most commonly spreads to the bones. It also sometimes spreads to other organs like the lungs or liver.

Grade: How aggressive is the cancer?

Doctors look at a small sample of the cancer under a microscope to see how abnormal the cells look. This gives a Grade Group from 1 to 5:

• Grade Group 1: The cells look almost normal. The cancer is slow-growing and less likely to spread.

• Grade Groups 2 & 3: The cancer is not considered slow-growing or aggressive.

• Grade Groups 4 & 5: The cells look very abnormal. The cancer is more aggressive and more likely to grow quickly.

You may also hear the term Gleason score. This is an older system that doctors still use. 

Gleason Score: How aggressive is the cancer?

When a doctor takes a biopsy, they take a small sample of tissue from your prostate. A specialist called a pathologist looks at it under a microscope. They are looking at how abnormal the cancer cells appear compared to normal, healthy cells.

Step 1: Find the two most common cell patterns. The specialist identifies the two most common types of cancer cells they see in the sample. Each pattern gets a score from 3 to 5 based on how abnormal it looks:

• 3 = cells look somewhat close to normal, and they are slow-growing

• 4 = cells look more abnormal, more aggressive

• 5 = cells look very abnormal, fastest-growing

(Scores of 1 and 2 are no longer used in modern medicine.)

What the Scores Mean:

Important note: A higher Gleason Score does not automatically mean the cancer cannot be treated. It just helps your doctor understand how quickly it may grow and what treatment approach is best.

How TNM and Gleason Score work together

This is an example to help you understand how TNM and the Gleason score work together. If your doctor says your cancer is T2, N0, M0 with a Gleason Score of 7 (3+4), here is what that means in plain language:

• The cancer is inside the prostate (T2)

• It has not spread to lymph nodes (N0)

• It has not spread to other parts of the body (M0)

• The cancer cells are mostly slow-growing, with some faster-growing cells (Gleason 7, Grade Group 2)

This would generally be considered intermediate-risk prostate cancer that needs treatment. 

Risk Groups: Putting It All Together

Doctors combine the stage, grade, and/or Gleason score to place the cancer into a risk group. This helps them decide the best treatment plan:

• Low Risk: The cancer is small, slow-growing, and contained in the prostate. Many men in this group can be watched closely without needing immediate treatment.

• Intermediate Risk: The cancer has some features that need attention, but it is still in or near the prostate. Treatment is usually recommended.

• High Risk: The cancer is more aggressive or has spread nearby. Treatment is typically more involved.

• Advanced (Metastatic): The cancer has spread to other parts of the body. Treatment focuses on controlling the cancer and managing symptoms.

Questions to ask your doctor

• What is my T, N, and M score? What does that mean for me?

• What is my Gleason Score and Grade Group?

• Based on these results, what risk group am I in?

• What are my treatment options?