07/18/2026
Partners in Prostate Regina are an affiliate group of PCFC and we would like to share information from their website regarding the grading & staging of prostate cancer.
https://prostatecanada.ca/
Prostate cancer’s confusing world of stage, grade, and risk groups
The short version
You just need to know two things:
A large majority of newly diagnosed men have potentially curable, localized prostate cancer. This group is subdivided into risk groups according to tumour features that predict the odds of successful cure.
In other men, prostate cancer has spread outside the range of curative local treatments.
The long version
As noted above, the key distinction is between those men with ‘apparently localised disease and, therefore, ‘potentially curable’ disease and those men with prostate cancer that has spread in a process known as metastasis. The latter are sometimes referred to as ‘stage 4 disease’ or ‘advanced prostate cancer’, but these two terms are not used consistently.
Men with metastatic disease
Metastatic prostate cancer may be present at diagnosis, or it may occur develop months or years after potentially curative treatments like surgery or radiation have failed, but in either case (with notable exceptions) men with metastatic prostate cancer are not typically offered curative treatment outside research protocols because the disease has spread beyond the range of localized treatments. This group of prostate cancer patients require ‘systemic’ therapy (usually drugs) that are effective at prolonging life, while delaying or preventing disability and suffering.
Men with localized disease
In about 85% of newly diagnosed cases, prostate cancer is ‘potentially curable’, by which we mean that safe, reliable treatments exist that often (but not always!) permanently eliminate the prostate cancer.
At diagnosis, the probability of successful cure depends heavily on certain features of the disease that can be measured prior to applying treatment. The idea of risk groups is to identify and group together cases that share similar odds of cure.
How is my risk group determined?
The NCCN risk stratification system is simple and has withstood the test of time; NCCN recognizes three risk groups (known as strata): low, intermediate, and high. Being ‘high-risk’ means the chances of successful cure after surgery and/or radiation are relatively low and vice versa for the low-risk group.
The NCCN system uses three independent prognostic factors: T-stage, tumour grade and PSA.
T-stage: the image above shows how the T-stage is determined.
Tumour Grade: Prostate tumors are assigned a Gleason Grade Group (GGG) based on biopsy. The GGG is based on the long-established Gleason grading system; it includes GGG1 which is lowest grade (least aggressive), GGG2 and GGG3 (intermediate) and GGG4 and GGG5 (most aggressive).
PSA: The pre-treatment PSA (called the iPSA), like clinical T-stage and biopsy GGG, is an independent predictor of success after curative treatment. The higher the PSA, the less likely that curative treatments will be successful.
Combining T-stage, GGG and PSA, the NCCN risk categories are determined as follows:
Low risk: must have all of: T-stage = T1-2a; GGG1 and iPSA < 10ng/mL
Intermediate risk: at least one of: T-stage = T2b-c; GGG2 or 3; iPSA >10 but 20 ng/mL
Most men in the low-risk category and some men in the intermediate-risk stata are suitable for active surveillance, while most men in the intermediate- or high-risk strata are encouraged to consider curative treatment without a long delay.
What is a pathologic T-stage?
The concept of T-stage becomes more complicated when you understand that there are two T-stages; one is called the clinical T-stage which is based on DRE and the other is called the Pathologic T-stage which can only be determined after surgical removal and microscopic examination. The distinction is vital because clinical T-stage is a clinical guess based on a qualified practitioner’s experience and education, while the pathologic T-stage is simply a fact.
This distinction is important because ‘upstaging’ of localized prostate cancer is often encountered when clinical TNM staging is compared to pathologic TNM staging for the same individual. To be specific, suppose patient X is considered to have clinical stage T2bN0M0 (which denotes organ-confined prostate cancer on DRE and no evidence of nodal or distant metastases on imaging). Now suppose patient X goes on to have surgery and careful examination surgical specimen reveals invasion of the seminal vesicles and two lymph nodes with cancer deposits. Patient X’s pathologic stage is T3bN1M0 which replaces his original staging as regards his prognosis for cure.
Also sometimes overlooked is the fact that pathologic TNM staging is impossible for men treated with brachytherapy or external radiation therapy is sometimes overlooked which has led to confusion regarding the relative efficacy of surgery and radiotherapy.
Risk Categories
Low
Intermediate
High
T-score
T1 to T2
T3
Cancer Growth
Least aggressive
Average
Most aggressive
Gleason Score
6
7
8 or more
Grade
Low
Medium
High
Gleason grades:
Grade 1: The tissue is still quite similar in appearance to healthy tissue; this is the least aggressive grade
Grade 2: The tissue is a little different from normal tissue
Grade 3: The tissue is moderately different from normal tissue
Grade 4: the tissue is abnormally shaped and quite irregular
Grade 5: the tissue is very different from normal tissue; this is the most aggressive grade
TNM stages:
T: (size of the tumour in the prostate)
T0: There is no evidence of tumour in the prostate
T1: The prostate seems normal and the tumour was discovered due to a high PSA measurement
T2: the tumour is palpable and confined within the prostate
T3: The tumour extends beyond the prostate (affecting the capsul, that is, the tissue surrounding the gland, and/or the seminal vesicles)
T4: The tumour has invaded neighbouring tissues (bladder neck, external sphincter, re**um, etc.)
N (degree of lymph node involvement):
N0: There is no evidence of a tumour in the lymph nodes
N+: One or more lymph nodes are involved
M (presence or absence of further metastases):
M0: There is no metastasis beyond the lymph nodes
M1: There is bone or distant metastasis
