The actual diagnosis of Prostate Cancer is made by way of biopsy, where tissue samples are taken during a procedure called a transrectal ultrasound guided prostate biopsy (TRUS).

During the procedure, a small ultrasound probe is inserted into the rectum and a series of pictures and measurements will be taken and the volume of your prostate will be calculated. A fine biopsy needle is then loaded through the ultrasound probe to take multiple specimens of prostate tissue. Normally 12 biopsies will be taken unless there are special circumstances in which case more biopsies will be taken, before being sent to a pathologist for assessment.

Staging and Grading

If prostate cancer is present then a stage and grade will be assigned to the prostate cancer.

Staging

Staging is the extent of the cancer, assessed by both physical examination and radiological scans such as a CT scan, bone scan, chest xray and occasionally an MRI scan.

The TNM system is used for staging (size of tumour, presence of lymph nodes, and metastases (or how far the cancer has spread)

• T = the tumour
• N = the lymph node or gland involvement
• M = the spread of cancer (metastases)

Grading

Grading is used by pathologists to describe the patterns of cancerous cells that are seen under the microscope. These patterns of cell formation then relate to the aggressiveness of cancer, its clinical characteristics and its potential future behavior. Based on the most common pattern of cells, the pathologist assigns a number from 1-5. 1 is the best and 5 is the worst. Based on the second most common pattern of cells the pathologist assigns a second number from 1-5. The sum of these 2 numbers is known as the Gleason score. Most prostate cancers have a Gleason score of between 6-10. Gleason score 6 is the least aggressive and Gleason score 10 is the most aggressive.