Prostate tumours are classified according to the tumour stage and the grade of aggressiveness of the tumour cells. These two elements are the basis for your possible treatment pathway.

The doctor does a series of tests to better understand your specific situation. Physical examination and imaging can be used to determine the stage of the disease. Prostate cancer is classified according to how advanced the tumour is, and whether or not the cancer has spread to the lymph nodes or other organs.

Prostate tumour stage is based on the TNM classification. The urologist looks at the size and invasiveness of the tumour (T) and determines how advanced it is, based on 4 stages. Your doctor will also assign an a, b, or c to the stage, depending on the size of the tumour.

Whether any lymph nodes around the prostate are affected (N) or if the cancer has spread to any other parts of your body (M) is also checked. If prostate tumours metastasize they generally spread to the bones, often the spine, or to the lungs, liver, or brain.

The Gleason score

The Gleason score ranges from 6 to 10. Tumours with a higher score are more aggressive and more difficult to cure.

The score is based on the pattern of the cancer cells. Each pattern gets a value between 1 and 5. The pathologist adds the scores of the two patterns that appear in most of the tissue samples.

For example: the most common pattern has a score of 3, and the second most common a score of 4. In this case, the Gleason score is 3 + 4 = 7.

Risk stratification

To form the risk stratification of your disease, the classification of the tumour is combined with your age, medical and family history, and general state of health.

Keep in mind that definitive classification of the tumour is only possible after you have had surgery to remove the entire prostate.