After prostate cancer is diagnosed, your cancer will be staged. Staging tells you how advanced the cancer is, how big it is in the prostate, and whether it has spread to other parts of the body, such as the nearby lymph nodes, liver, and bone.

Knowing the stage of your cancer provides important information about the best treatment options, the likelihood that the cancer can be cured, or whether it is so slow growing that you can safely pursue active surveillance (watch and wait), with routine monitoring by your physician.

The stage at which your cancer was initially diagnosed is the stage that doctors will use throughout, even if cancer moves to a more advanced stage, according to the American Society of Clinical Oncology (ASCO).

What Goes Into Prostate Cancer Staging?

Doctors consider several factors when they assign a stage to your cancer.

Prostate Cancer Stages Range
From 1 to 4

This information is put together to group cancer into stages 1 to 4, the ACS says, with stage 1 the earliest prostate cancer and stage 4 when the cancer has spread throughout the body.

Stage 1: Prostate cancer is limited to a small part of the prostate.

• Often, the cancer is found as a result of needle examination of tissue for another reason, such as benign prostatic hypertrophy (BPH), also known as an enlarged prostate, or because of an elevated result on a PSA test.
• Cancer cells are only found in a small part of the prostate. The cells look like normal cells and the prostate feels normal with a digital rectal exam (DRE).
• PSA is less than 10.
• Gleason score is less than 6.

Stage 2: Prostate cancer involves more of the prostate and a lump is detectable in an exam.

This category is divided into two stages: 2A and 2B.

In stage 2A, features are like stage 1, with these changes:

• PSA is at least 10, but less than 20.
• Gleason score is 6 but can be lower if diagnosis was by needle biopsy for conditions other than cancer.
• Cancer can be found in one-half or less of the prostate lobe or more than one lobe.

Stage 2B cancer means that:

• The prostate cancer is more extensive, extending to opposite sides of the prostate. It might be detectable with a digital rectal exam. In this instance, the PSA is lower than 20 and the Gleason score is 7, according to the National Cancer Institute.
• Alternatively, cancer remains undetectable in the digital rectal exam and imaging tests. PSA is lower than 20 and the Gleason score is 7.
• Yet another way this can manifest is with a Gleason score of 8 or more, PSA at any level, but imaging and DRE do not pinpoint the cancer.

Stage 3: Prostate cancer extends to the outer layer of the prostate and may involve the seminal vesicles. These point to a locally advanced cancer that will grow and spread.

• PSA can be any value and the Gleason score is between 2 and 10.

Stage 4 (Metastatic): The cancer is at its most advanced and has spread, or metastasized, to the lymph nodes and potentially other organs.

• The cancer may have spread to the lymph nodes or bone.

Recurrent Prostate Cancer

Recurrent cancer is cancer that comes back after curative treatment. It might come back where it was initially diagnosed or elsewhere in the body. When this occurs, men may need to go through the same tests that they had when initially diagnosed, the ACS says.

Risk Assessment: Establishing Risk Groups

According to the PCF, doctors classify patients into three risk groups: high-, intermediate-, and low-risk. Risk groups are based on considering the TNM stage, PSA, and Gleason score.

What Constitutes Low-Risk Prostate Cancer?

Low-risk prostate cancers grow very slowly. You will be low-risk if your PSA is less than 10, you have a Gleason score no higher than 6, and a T stage between T1 and T2A. Low-risk patients are considered candidates for active surveillance, radical prostatectomy, or radiation.

What Are Intermediate- or Medium-Risk Cancers?

Medium-risk cancers probably won’t grow or spread for a few years, but curative therapy (prostatectomy or radiation) is recommended. In addition, they are usually treated with less than six months of a gonadotropin-releasing hormone medication (hormone therapy). Your doctor will put you in this category if you have a PSA between 10 and 20, a Gleason score of 7, and a T stage of T2B.

What Are High-Risk Cancers?

A high-risk cancer means that your cancer is expected to grow and spread in the next few years. If you have a PSA greater than 20, a Gleason score between 8 and 10, and a T stage of T2B, you will be considered high-risk. Men at high risk are often given radiation and a longer period of hormonal therapy. Developing better treatments for high-risk patients is a key goal of prostate cancer research, according to the ACS.

Genomic Testing

Inroads in prostate cancer biology have led to new molecular tests that, when considered along with risk groups, Gleason score, and PSA, can give information on the aggressiveness of the tumor. Molecular testing is recommended in men who want to choose active surveillance, have low- or intermediate-risk disease with a life expectancy of more than 10 years, or who have advanced disease, the National Comprehensive Cancer Network says.