Your doctor may use a range of tests to diagnose prostate cancer; common procedures include:  

Digital rectal examination (DRE)
This is a quick and safe procedure during which a doctor or nurse inserts a lubricated, gloved finger into the rectum and feels for abnormal lumps or hard irregular areas, through the wall of your rectum. The prostate gland should feel soft, smooth and even. Tumours which are small and located only within the prostate are often not detected during a DRE .

Figure 1: Digital-rectal-examination

Prostate-specific antigen (PSA) test
A simple, painless test that measures the levels of PSA in a blood sample. PSA is a substance produced by the prostate that is present in higher-than-normal levels in the blood of men with prostate cancer. Normal PSA levels are between 0 and 4 nanograms per millilitre (ng/mL). PSA often rises as part of the natural ageing process and an increase in PSA does not necessarily indicate that prostate cancer is present. High PSA levels may also be found in men who have infection or inflammation of the prostate (prostatitis), or who have a non-cancerous condition called BPH (benign prostatic hyperplasia). If your PSA levels are high, your doctor may recommend that you have a transrectal ultrasound, to rule out prostate cancer.

Transrectal ultrasound
A painless procedure in which an instrument is inserted into the rectum and sound waves bounce off the prostate, producing a picture of the prostate which can be used to help identify abnormal areas requiring a biopsy. If the results of the transrectal ultrasound are normal, you may be able to wait and repeat the PSA test a few months later and then have a biopsy if needed.

Biopsy
In this procedure a sample of cells, tissue or fluid is removed from the prostate and viewed under a microscope, to check for signs of the disease. There are two types of biopsy:

• Transrectal biopsy: a needle is inserted through the rectum into the prostate and a sample of prostate tissue is removed.

Figurre 3: Transrectal biopsy

• Transperineal biopsy: a needle is inserted through the skin between the scrotum and rectum into the prostate and a sample of prostate tissue is removed.

Both biopsy procedures are short and you can usually go home the same day. A biopsy is the only way to confirm or diagnose the presence of prostate cancer.

If you have been diagnosed with prostate cancer, your specialist may want to carry out some further tests to find out if the cancer has spread to other parts of the body. The results of these tests will help your doctor to decide which is the best type of treatment for you. These tests include:

Visual imaging procedures   

Radionuclide bone scan
A procedure in which a small, harmless amount of radioactive material is injected into a blood vessel. It travels through your bloodstream and collects in the bones where it is detected by a scanner to produce images of your bones .

MRI (magnetic resonance imaging)
A painless, procedure in which a high-powered magnet linked to a computer is used to create a picture of the prostate and other nearby parts of the body.  

CT (computer tomography) scan
A procedure in which a computer linked to an x-ray machine creates a series of detailed pictures of the prostate and nearby tissues.

Tissue sampling

Seminal vesicle biopsy  
A procedure in which a needle is inserted into your seminal vesicles (glands that produce semen) and fluid is removed and checked for cancer cells . 

Pelvic lymphadenectomy  
A surgical procedure in which lymph nodes in your pelvis are removed to check if the cancer has spread to them. This is usually done during surgery to remove the prostate.

Some or all of the tests identified above are used to help your doctor determine the Stage that your cancer has reached.

Stages of prostate cancer
The following stages are used for prostate cancer:

• Stage I (Localised): cancer found in the prostate only 
• Stage II (Localised): cancer is more advanced but has not spread outside the prostate 
• Stage III (Locally advanced): cancer which has spread beyond the outer layer of the prostate to nearby tissues 
• Stage IV (Advanced/metastatic): cancer has spread to other parts of the body
• Recurrent prostate cancer is cancer that has come back after it has been treated   

There are other methods of staging prostate cancer, the most common of which is the TNM system, which stands for Tumour, Node and Metastases. T refers to the size of the primary tumour, N describes the extent of lymph node involvement and M refers to the presence or absence of metastases (secondary tumours).