Prostate Cancer Knowledge Centre
Epidemiology and Classification
Classification
Histological Classification
The majority of prostate tumours are adenocarcinomas arising from the epithelium in the peripheral zone of the gland.1
The Gleason score is the most widely used system for grading prostate tumours and identifies five different patterns of differentiation evident on pathological examination of biopsy material (patterns 1–5).1-3
Since prostate tumours often exhibit heterogeneous histology, the two most prominent grades are added together to give the final Gleason score (e.g. 3 + 4).1 High Gleason scores indicate a poorly differentiated tumour that is associated with more aggressive disease.1 Patient information on this topic can be found at Unitedagainstprostatecancer.com.
The Gleason score1 (Adapted with permission from Kirby and Patel, 2008)
| Gleason score | Histological features | Example | 10-year risk of local progression (%) |
|---|---|---|---|
| 2-4 | Well differentiated |  Prostate cancer nodule in specimen from transurethral resection of the prostate (Gleason score 1 + 2 = 3) |
25 |
| 5-7 | Moderately differentiated |  Prostate carcinoma composed of small discrete glands (Gleason score 3 + 3 = 6) |
50 |
| 8-10 | Poorly differentiated |  Adenocarcinoma with fused glands (Gleason score 4 + 4 = 8) |
75 |
Images reproduced [permission to be confirmed] from Epstein et al, 20053
References:
1. Kirby RS, Patel MI. Fast facts: prostate cancer (5th ed). Health Press Ltd: Oxford, 2008.
2. Gleason DF, Mellinger GT. Prediction of prognosis for prostatic adenocarcinoma by combined histological grading and clinical staging. J Urol 1974;111:58-64.
3. Epstein JI, Allsbrook WC Jr, Amin MB, Egevad LL; ISUP Grading Committee. The 2005 International Society of Urological Pathology (ISUP) Consensus Conference on Gleason Grading of Prostatic Carcinoma. Am J Surg Pathol 2005;29:1228-42.