Although the following tests can be used to diagnose cancer of the prostate you do not need to have all of them done. The advantages and disadvantages of each method should be explained to you before you agree to any of them. Your doctor will be able to tell you how and when you will get the results.

As the rectum (back passage) is so close to the prostate gland, your doctor can feel any abnormalities in the prostate by inserting a gloved finger into the rectum. This may be uncomfortable but should not be painful.

If cancer is present in the prostate gland it may feel hard and knobbly, whereas with BPH it is usually enlarged, firm and smooth. However, sometimes the prostate may feel normal, even when cancer cells are present.

You will be recommended to have a blood test called PSA.

PSA is a substance produced by both normal and cancerous prostate cells. When prostate cancer grows or when other prostate diseases are present, the amount of PSA in the blood often increases.

• A PSA test is generally said to be in the normal range when it is reported to be between 0 and 4 nanograms per milliliter, sometimes abbreviated as ng/mL on the lab report.
  
  
• If the results are in the high range (reported to be greater than 10 ng/mL), then your physician will suggest a biopsy, which is the only test to actually diagnose prostate cancer.
  
  
• Sometimes, PSA results are in the “borderline high” range. This occurs when the results are between 4 and 10 ng/mL. PSA test results in this range can be confusing and do not always mean that cancer is present. Certain other conditions, such as benign prostatic hyperplasia (also called BPH — a type of noncancerous prostate enlargement) and prostatitis (inflammation of the prostate), may cause an abnormal PSA result.
  
  

Trans-rectal ultrasound scan (TRUS)
Ultrasound scans use sound waves to build up a picture of the inside of the body. To scan the prostate gland a small probe is passed into the back passage and the image of the prostate appears on a screen. This type of scan is used to measure the size and density of the prostate. A sample of cells (biopsy) can be taken at the same time for examination under the microscope by a pathologist.

The scan may be uncomfortable but it only takes a few minutes.

Biopsy
If the initial tests (rectal examination, PSA or ultrasound) show that there is a possibility of cancer, you may be asked to have a biopsy, in which a sample of cells is taken from the prostate to be looked at under a microscope. The biopsy is usually done at the same time as the ultrasound. A needle is passed through the wall of the back passage (rectum) and into the prostate. This test is usually uncomfortable, and can sometimes be painful, but it does not need a general anaesthetic. Antibiotics are given to reduce the risk of infection. For a few days following this test you may notice bleeding when passing water, when having your bowels open or after sex.

Unfortunately, even if there is cancer in the prostate it may not be picked up on biopsy. This occurs in approximately one fifth of men. If a biopsy is negative it may need to be repeated (which will detect most of the cancers missed first time) or the PSA may be measured again after a few months and the biopsy repeated if the PSA level starts to rise.

If the biopsy shows that a cancer is present further tests will be needed to check whether the cancer has spread beyond the prostate gland. These may include:

X-rays
A chest x-ray and x-rays of the bones are often taken to check your general health and see if there has been any spread of the cancer to other parts of the body.

Isotope bone scan
A very small amount of mildly radioactive liquid is injected into a vein, usually in your arm. A scan is then taken of the whole body. Abnormal bone absorbs more of the radioactive substance than normal bone and shows up on the scan as highlighted areas (known as 'hot spots').

After the injection you will have to wait for up to three hours before the scan can be taken, so it is a good idea to take a book or magazine with you.

The level of radioactivity that is used is very small and does not cause any harm.

This scan can also detect other conditions affecting the bones such as arthritis, so further tests such as an X-ray of the abnormal area may be necessary to confirm that it is cancer.

CT scan (CAT scan)
A CT scan takes a series of pictures of an area of the body. These are fed into a computer which creates detailed pictures of the inside of the body. A CT scan may show if the cancer has spread beyond the prostate to other parts of the body such as the lymph glands

The scan takes from 10-30 minutes. You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. For a few minutes, this may make you feel hot all over. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it is important to let your doctor know beforehand.

You will probably be able to go home as soon as the scan is over.

Magnetic Resonance Imaging (MRI or NMR scan)
This test is similar to a CT scan but uses magnetism instead of X-rays to build up cross-sectional pictures of your body.

More information on the prostate can be obtained from The Prostate Cancer Charity www.prostate-cancer.org.uk

 

Last modified 7 Jan 2007