Understanding Prostate Cancer Risk Groups

At Rocky Mountain Cancer Centers, creating a personalized treatment plan for prostate cancer includes identifying your risk group. Your PSA test result, the Gleason score, and the tumor’s clinical stage (T category) are combined to identify high, intermediate, and low-risk groups. The risk groups provide a better understanding of how fast the cancer is growing and how likely it is to spread beyond the prostate.

This information guides the oncologist on when to start treatment and which treatments would be most effective.

• Low-Risk: Slow-growing Prostate Cancer
  • Cancer is confined to the prostate and clinically staged at cT1 to cT2a.
  • PSA level is <10. 
  • Grade group 1 (Gleason score of 6) - slow-growing cancer.

NOTE: A subcategory called "very low-risk" indicates a slow-growing cancer slightly smaller than what is considered low-risk. The tumor is most likely categorized as cT1c.

Most low-risk patients will be able to wait before starting treatment. Learn more about this in our blog.

• Intermediate-Risk: Favorable or Unfavorable
  • Cancer is confined to the prostate but may be found on more than half of one side (cT2b) or both sides (cT2c). These tumors can usually be felt during an exam.
  • PSA level is between 10 and 20.
  • Grade group 2 or 3 (Gleason score of 7).

Subcategories of "favorable" or "unfavorable" are given to those in the intermediate-risk group. 

• • Favorable results indicate that the cancer is less likely to grow beyond the prostate. This is often associated with those whose Gleason score was 3+4=7 (Grade group 2) or cancer was found in less than half of the prostate biopsy core samples. The oncologist may recommend active surveillance. However, if you have a preference for starting treatment sooner, be sure to discuss the pros and cons of starting right away.
  • Unfavorable indicates that the cancer is more likely to spread beyond the prostate. Patients with a Gleason score of 4+3=7 (Grade group 3) or who had cancer that was found in more than half of the prostate biopsy core samples will more than likely need to start treatments sooner to avoid cancer spread.

Learn more about a Gleason score of 7 in our blog.

• High-Risk: Aggressive Prostate Cancer

These patients need only one of the following to be considered high-risk:

• • Cancer has grown beyond the prostate, staged at CT3a
  • PSA level is 20 or more.
  • Grade group 4 or 5 (Gleason scores of 8 to 10)

NOTE: A highly aggressive form of prostate cancer is called “very high-risk” if the cancer has at least two of the above characteristics. Or, the tumor is found in the seminal vesicles (cT3b) or in other areas of the body (cT4). For these patients, the most common areas in the biopsy results have a Gleason score of 5.

Both high-risk and very high-risk patients will receive treatment immediately. Depending on the size of the tumor and its location, several treatments are typically used.

Related Reading: What You Should Know About Your Prostate Pathology Report

Understanding How Prostate Cancer Spreads

Prostate cancer progresses through three key growth stages:

1. Cancer Development and Growth
   During this initial step, prostate cancer develops and remains within the prostate gland. The prostate is encased by a protective capsule similar to an eggshell surrounding the egg.
2. Microscopic Capsule Penetration
   If left untreated, cancer cells can penetrate the capsule, causing cancer cells to leak outside of the prostate. This is known as microscopic capsule penetration.
3. Metastasis
   If cancer cells remain after treatment, or cancer has not been diagnosed up to this point, prostate cancer spreads beyond the prostate. This can be locally advanced, in which the cancer is found in nearby structures, such as the seminal vesicles, lymph nodes, bones, lungs, or other parts of the body. 

Treatment is most effective and easiest for patients to manage when cancer is found earlier when the tumor is small and cancer cells have not yet spread beyond the prostate. However, many treatment options are currently available, with more in the clinical research process for advanced prostate cancer treatments. 

Learn more about advanced prostate cancer treatment options at RMCC.

How Prostate Cancer Cells Escape the Capsule

Cancer cells can penetrate the prostate capsule in four different ways, allowing cancer cells to spread to the lymph nodes and attach to other areas of the body. 

1. Capsule Destruction
   Cancer destroys the capsule near where it’s growing and escapes the prostate. It is similar to a small hole in an eggshell that allows the egg to start seeping out.
2. Perineural Invasion
   Perineural invasion refers to cancer spreading along the small nerves surrounding the prostate. These nerves create tunnels through the prostate capsule, allowing cancer cells to escape and spread. Perineural invasion usually indicates a higher risk of microscopic capsule penetration and a lower likelihood of complete cancer removal.
3. Capsule-Free Apex
   The prostate’s bottom (apex) is not protected by the capsule, allowing cancer cells to escape more easily from this area, even if you’ve had a prostatectomy. There may be some microscopic cancer cells left behind that can move beyond the prostate. Because of this, radiation therapy after surgery is a good option for many patients. By treating the surgical area with radiation, the unseen cancer cells are destroyed before they can spread.
4. Seminal Vesicle Invasion
   Cancer invades the seminal vesicles attached to the top of the prostate.

Personalized Prostate Cancer Treatment Planning in Colorado

If you were diagnosed with prostate cancer, it’s a good idea to consult an oncologist for a discussion of the best next steps – which may not include surgery right away.

The oncologist will discuss your risk group, how it affects your treatment recommendations, and when to start treatments. We hope this information provides a sense of what you might expect based on your risk group.

At Rocky Mountain Cancer Centers, our team is ready to assist patients who were just diagnosed with prostate cancer as well as those who have recurrent prostate cancer. Request an appointment with one of our specialists at a Colorado cancer center that’s convenient for you.