How is prostate cancer diagnosed?
A diagnosis usually begins after a man sees his GP with some or all of the following common symptoms:
- Difficulty passing urine
- Passing urine more frequently
- Sudden urges to go to the toilet
- Bone pain in hips and lower back (less frequent)
What tests are used?
If prostate cancer is suspected then there are a variety of tests that may be used to make a diagnosis. These include, but are not limited to:
- Prostate Specific Antigen (PSA) test
- Digital Rectal Examination (DRE)
- Ultrasound scan
- MRI scan
- CT scan
- Bone scan
The PSA test is a blood test that measures levels of Prostate Specific Antigen (PSA). PSA is a type of protein produced by the prostate gland. All men have a small amount of PSA in their blood. In men with prostate cancer PSA levels are usually higher than normal. The higher the level of PSA, the more likely a man has prostate cancer. However, the PSA test is not always reliable.
PSA levels also increase with age or if you have a urine infection, enlargement of the prostate, or inflammation of the prostate (prostatitis).
If your PSA level is high you will need other tests, including repeated PSA tests, to confirm a diagnosis of prostate cancer.
Digital Rectal Examination
A Digital Rectal Examination (DRE) is where the doctor puts a finger into the back passage (rectum) to feel the prostate gland. The doctor can tell if the prostate gland feels enlarged or different from a normal prostate gland by doing this.
A biopsy is where small samples of the prostate gland are removed and looked at under a microscope. A small needle is used to collect the samples. This is usually done through the back passage (rectum).
Biopsies are used to see if the cells in the prostate gland are abnormal and to find out how quickly the cancer is likely to grow (the grade of the prostate cancer). Usually an ultrasound scanner is used to guide the biopsy needle.
An ultrasound scan can be used to measure the size and density of the prostate gland. It is usually carried out at the same time as a biopsy. A small ultrasound scanner is put up the back passage. The ultrasound scanner produces sound waves, which help to create a picture of the prostate gland.
MRI and CT scans
MRI (magnetic resonance imaging) and CT (computerised tomography) scans give images of the inside of the body. This is so the doctor can see if prostate cancer has spread to areas near to the prostate gland such as the lymph nodes.
During an MRI or CT scan you will lie on a bed while a machine takes pictures of your prostate gland and surrounding areas. Both MRI and CT scans are completely painless tests.
If it is possible that prostate cancer is metastatic (advanced), a bone scan may be carried out to see whether or not it has spread to your bones.
A small amount of radioactive dye is injected into a vein. The dye travels around your body and collects in the bones. Your body is then scanned using a gamma camera, which can detect radioactivity. Areas where there is a lot of radioactivity in the bones indicate they may have cancer in them.
Like MRI and CT scans, bone scans are completely painless tests. There may be some very slight discomfort when the radioactive dye is injected into the vein.