Staging of Prostate Cancer (How far the cancer has progressed)

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 the most relevant; it is described in full below.

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:   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..

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.

The diagrams below show 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.