The staging of prostate cancer

The system of staging prostate cancer is known as the TNM system (tumour-nodes-metastasis). The T stage of the disease refers to the form of the primary tumour in the prostate. As this is perhaps the most relevant, it is described in full. The N stage of the disease refers to the pelvic lymph nodes near the prostate; the M stage to the degree of metastasis, ie the degree to which the prostate cancer has travelled out of the immediate area of the prostate.

T stage disease

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

T1a: Cancer is found incidentally during a transurethral resection (TURP) for benign prostate enlargement and is present in less than 5% of the tissue removed.

T1b: Cancer is found after TURP and is present in more than 5%.

T1c: Cancer is found by needle biopsy done because of an elevated PSA.

T2: Doctor can feel that tumour appears 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 only 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 may be fixed to the pelvic wall.

N and M stages

N stage disease is rated from 0 to 3, depending on the presence and extent of the spread to the pelvic lymph nodes, N1 being up to 2cm, to N3 being greater than 5cm. M stage disease is rated 0, M1a, M1b or M1c, depending on whether the disease has spread to the bones or other distant sites.

Your category

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

PSA Gleason Clinical stage
Low risk up to 10 and 6 or less and T1-T2a
Intermediate risk 10-20 or 7 or T2b
High risk More than 20 or 8-10 or T2c or more