Prostate Cancer Staging
After a prostate cancer diagnosis, determining the stage of the disease is one of the most important next steps. Staging describes how much cancer is present, whether it has spread, and how aggressive it appears based on PSA level and Gleason score.
The oncologists of Blue Ridge Cancer Care will review images, blood test results and the biopsy report to stage the cancer and recommend a treatment plan.
How Prostate Cancer Is Staged
Prostate cancer staging is based on several factors:
- TNM system (Tumor, Nodes, Metastasis)
- PSA (Prostate-Specific Antigen) level at diagnosis
- Gleason score from the prostate biopsy
All three components work together to determine the overall stage group, which ranges from Stage I to Stage IV.
Understanding the TNM System
T (Tumor)
Describes the size of the tumor and whether it is confined to the prostate or has grown beyond it.
N (Nodes)
Indicates whether cancer has spread to nearby lymph nodes.
- N0: No lymph node involvement
- N1: Cancer has spread to nearby lymph nodes
M (Metastasis)
Indicates whether cancer has spread to distant parts of the body.
- M0: No distant spread
- M1: Cancer has spread to bones or other organs
Why PSA and Gleason Score Matter in Staging
PSA level and Gleason score significantly influence stage grouping because they reflect how active and aggressive the cancer may be.
- A higher PSA can indicate more advanced or more active disease.
- A higher Gleason score suggests more abnormal cells and a greater likelihood of growth and spread.
Together with TNM findings, these numbers provide a complete picture of the cancer.
Stage I Prostate Cancer
Stage I prostate cancer is confined to the prostate and is usually small. It may not be felt during a digital rectal exam and is often detected because of an elevated PSA. Stage I prostate cancer is typically slow-growing and considered lower risk.
TNM: T1 or T2a, N0, M0
PSA level: Less than 10
Gleason score of 6
Stage II Prostate Cancer
Stage II prostate cancer is still confined to the prostate but may be larger or associated with a higher PSA or Gleason score than Stage I. Stage II is divided into subgroups based on PSA and Gleason score.
Stage IIA
Cancer remains within the prostate.
TNM: T1 or T2, N0, M0
PSA level: Less than 20
Gleason score of 6
Stage IIB
Cancer is still confined to the prostate.
TNM: T1 or T2, N0, M0
PSA level: Less than 20
Gleason score of 7 (3+4=7)
Stage IIC
Cancer remains within the prostate but is considered higher risk due to biopsy findings.
TNM: T1 or T2, N0, M0
PSA level: Less than 20
Gleason score of 7 (4+3=7) or 8
Stage III Prostate Cancer
Stage III cancer has extended beyond the prostate but has not spread to lymph nodes or distant organs.
Stage IIIA
Cancer may still be confined to the prostate, but a significantly elevated PSA.
TNM: T1 or T2, N0, M0
PSA level: 20 or higher
Gleason score of 6 to 8
Stage IIIB
Cancer has grown through the outer layer of the prostate and may involve nearby tissues.
TNM:T3 or T4, N0, M0
PSA: Any level
Gleason score of 6 to 8
Stage IIIC
Cancer may or may not have spread beyond the prostate, but biopsy findings indicate very aggressive disease.
TNM: Any T, N0, M0
PSA: Any level
Gleason score of 9 or 10
Stage IV Prostate Cancer
Stage IV prostate cancer has spread beyond the prostate to lymph nodes and/or distant parts of the body. This is also referred to as metastatic prostate cancer or distant prostate cancer when it advances to other organs.
Stage IVA
Cancer has spread to nearby lymph nodes but not to distant organs.
TNM: Any T, N1, M0
PSA: Any level
Gleason score: Any score
Stage IVB
Cancer has spread to distant areas such as bones, distant lymph nodes, or other organs.
TNM: Any T, Any N, M1
PSA: Any level
Gleason score: Any score
Prostate Cancer Risk Groups
In addition to staging, prostate cancer is also classified into risk groups that help your oncologist estimate how likely the cancer is to grow or spread. This is also a part of the overall treatment planning decision process.
Risk groups are determined using:
- PSA (Prostate-Specific Antigen) level
- Digital rectal exam (DRE) findings
- Prostate biopsy results, including the Gleason score
Low-Risk Prostate Cancer
Low-risk prostate cancer is typically:
- Confined to the prostate
- Associated with a PSA level less than 10
- Gleason score of 6
These cancers tend to grow slowly and are unlikely to spread outside the prostate in the near term. Many men with low-risk prostate cancer have no symptoms.
A subset known as very low-risk prostate cancer includes tumors that are small, may not be detectable on digital rectal exam, and involve only a small amount of cancer found on biopsy samples.
Intermediate-Risk Prostate Cancer
Intermediate-risk prostate cancer is still confined to the prostate but shows features that suggest a higher likelihood of growth compared to low-risk disease. This group typically includes:
- PSA levels between 10 and 20
- Gleason score of 7
Intermediate-risk prostate cancer is often divided into favorable intermediate-risk, where the cancer may be expected to grow more slowly and unfavorable intermediate-risk, where the cancer is more likely to grow or spread quicker.
High-Risk Prostate Cancer
High-risk prostate cancer has characteristics that suggest a greater likelihood of spread or recurrence. This group may include at least one of the following:
- PSA greater than 20
- Gleason score of 8, 9, or 10
- Tumor extension beyond the prostate
A subset called very high-risk prostate cancer includes tumors that have grown into nearby structures such as the seminal vesicles, bladder, or rectum, or cancers where multiple biopsy samples show high-grade disease.
What’s next after staging?
Once the stage is determined, your oncologist will discuss the recommended next steps, which can range from watchful waiting to starting a treatment plan right away. Earlier stages of prostate cancer may be able to delay or avoid surgery to remove the prostate, while later stages may require a prostatectomy to ensure all of the cancer cells are removed. Talk with your oncologist and your urologist about their recommendations for you.