Staging of Prostate Cancer

The current system of staging prostate cancer is known as the TNM system (standing for ‘Tumour/Nodes/Metastasis’). The T stage of the disease refers to the form of the primary tumour in the prostate. This is perhaps the most relevant; it is described in full below.

Prostate Cancer Stages

 

 

 

 

 

 

Stages T1 to T4, where the tumour (in yellow) develops from 
a small size to one where it has spread outside the prostate 
(in grey) to other structures.

T Stage disease

T1: The doctor is unable to feel the tumour or see it with imaging

  • T1a: Cancer is found incidentally during an operation for benign prostate enlargement (called a transurethral resection of the prostate, or TURP) and is present in less than 5% of the tissue removed.
  • T1b: Cancer is found after a TURP and is present in more than 5%.
  • T1c: Cancer is found by needle biopsy.

T2: Doctor can feel that the tumour seems to be confined to the prostate

  • T2a: Cancer is found in one half or less of only one side of the prostate.
  • T2b: Cancer is found in more than half of one side of the prostate.
  • T2c: Cancer is found in both sides of the prostate.

T3: Cancer has begun to spread outside the prostate

  • T3a: Cancer extends outside the prostate but not to the seminal vesicles.
  • T3b: Cancer has spread to the seminal vesicles.

T4: Cancer has spread to other tissues next to the prostate

  • T4a: Cancer invades bladder neck, sphincter, or rectum.
  • T4b: Tumour has invaded the levator muscles and/or fixed to the pelvic wall.

N and M Stages

N Stage disease refers to the pelvic lymph Nodes near the prostate. It is rated from 0 to 3, depending on the presence and extent of the spread, N1 being up to 2cm, to N3 being greater than 5cm.

M Stage disease refers to the Metastasis, i.e. the degree to which the prostate cancer has travelled out of the immediate area of the prostate to other organs of the body. It is rated 0, M1a, M1b or M1c, depending on whether the disease has spread to the bones or other distant sites.

Your Risk Category

The NICE Guidelines for Prostate Cancer (2014) give three categories of risk: low risk, intermediate risk and high risk, depending on a combination of PSA, Gleason score and T stage. Knowing your risk category will help decide the most appropriate treatment for you. The table below will help.

 Risk PSA   Gleason   T Stage
Low <10 AND <6 AND T1-T2a
Intermediate 10 - 20 OR 7 OR T2b-T2c
High >20 OR 8-10 OR T3-T4