There are two tests that are used to look for prostate cancer: a digital rectal exam (DRE) and a blood test that is called PSA. The PSA blood test looks for something called prostate-specific antigen in the blood. Last week, we made mention of the PSA.

PSA levels in blood are higher if there is prostate cancer, making it a valuable tool in finding early prostate cancer. But PSA levels can also be high from infection or inflammation in the prostate or from an enlarged prostate. Therefore, an increased PSA level does not necessarily confirm that there is prostate cancer. It gives an indication that something may be wrong and so there is the need for further examination and tests to be done.

It is important to discuss this test with your doctor before having one, so that you do not misinterpret the results. Just like a high PSA level does not mean that you have cancer, a normal PSA level does not mean you don’t have cancer. Great care should be taken when reading and interpreting the results.

If PSA levels are high, or have gone up since the last PSA test, your doctor will do a biopsy of the prostate gland, using a small ultrasound probe inserted in the rectum (transrectal ultrasound). The tissue samples collected during this procedure will be sent to the lab to be tested for cancer.

If cancer is found, the doctor will do abdominal and pelvic X-rays to see if the cancer has spread outside the prostate. A CT scan and a bone scan may also be done to determine how far the cancer has spread.

For men who have high PSA levels, but biopsies don’t find cancer, there is a urine test known as a PCA-3 that looks for cancer. This test can prevent the need for repeat biopsies in some men.

The digital rectal examination, also called DRE, is used to see if you might have a prostate problem or prostate cancer. It involves your doctor or nurse feeling the prostate through the wall of the rectum. The prostate may feel: normal – a normal size for your age with a smooth surface; larger than expected for your age – this could be a sign of an enlarged prostate; hard and lumpy – this could be a sign of prostate cancer.

The DRE is not a completely accurate test. Your doctor or nurse can’t feel the whole prostate and so a man with prostate cancer might have a prostate that feels normal.

If you have a DRE that is abnormal, your doctor or nurse might suggest waiting a week before having a PSA test. This is because having a DRE just before a PSA test could slightly raise your PSA level.

If you have any concerns, please sit with your physician to discuss your risk of prostate cancer and what tests can be done for you.

Next Week: Treatment of Prostate Cancer.

Dr Rosmond Adams, MD is a medical doctor and a public health specialist. He is also an ethicist with training in research ethics and medical ethics. He is the head of Health Information, Communicable Disease and Emergency Response at the Caribbean Public Health Agency (CARPHA).

He is also a member of the World Health Organization (WHO) Global Coordination Mechanism (GCM) on the Prevention and Control of Non-Communicable Diseases (NCDs).

(The views expressed here are not written on behalf of CARPHA nor the WHO)

Dr Rosmond Adams is a medical doctor and a public health specialist. He may be emailed at:adamsrosmond@gmail.com