There are approximately 25,000 men newly diagnosed with prostate cancer every year in the United Kingdom. For these men the risk of dying from their prostate cancer depends on a number of risk factors. For example if the cancer is confined to the prostate gland at diagnosis the chance of surviving to 5 years is 70%. If the cancer has already spread e.g. to the bones then only 20% of men will survive to five years. Of all the men who currently have prostate cancer in the UK approximately 10,000 will die of the disease each year. The prostate cancer survival rate is much higher in the developed world - unsurprisingly.
When a man is first diagnosed with prostate cancer then the doctor who has found the cancer (most often a “urologist” – a surgeon who specialises in looking after problems to do with the kidneys, prostate and bladder) will arrange a series of tests to help assess the risk for that individual patient. The results of these tests will in turn help the doctor and patient to decide the best treatment for that patient.
PROSTATE CANCER TESTS TO HELP PREDICT SURVIVAL
1. Prostate Specific Antigen or PSA
2. Digital Rectal Examination or DRE
3. Trans-rectal Ultrasound and Biopsy
4. CT or MRI Scan
5. Bone Scan
This is a protein made by the prostate gland which can be measured on a sample of your blood i.e. a blood test. The PSA level can be raised by non cancerous problems with the prostate gland i.e. not all men who have a raised PSA have prostate cancer. Also some men who have prostate cancer will not have a raised PSA. However PSA does tend to increase as prostate cancers grow, invade and spread so PSA can be used to monitor how a prostate cancer is progressing or how it is responding to treatments.
This is where a doctor feels the prostate gland through the back passage. It tells the doctor how big the prostate gland is, whether the cancer is able to be felt easily and whether it has invaded the area near by.
TRAN-RECTAL ULTRASOUND AND BIOPSY
For this test you need to lie on your side with your knees brought up into the chest (same position as for a DRE). An ultrasound probe is then inserted into the back passage. This enables the doctor to see on a screen the outline of the prostate gland. There is no radiation involved. The image on the screen then allows the doctor to insert a needle safely into the prostate gland to take some samples of the prostate tissue. Usually several samples are taken from each area of the prostate gland. These samples are then sent to a laboratory to be looked at under a microscope. This allows confirmation that there is prostate cancer present and tells us how aggressive the cancer looks. Sometimes a local anaesthetic is used to help make the procedure more comfortable.
CT OR MRI SCAN
This is usually carried out in an x-ray department and involves lying still on a thin couch which moves through either a big donut (CT) or into a long tunnel (MRI). This is not painful in any way. The pictures gained from this test helps the doctors to see whether the prostate cancer is still within the prostate gland or whether it had started to invade out of the gland into other surrounding structures. This tells the doctor what “stage” the prostate cancer is.
This requires you to have an injection and then to lie on a special table where a camera scans the whole body. It shows up whether any of the bones in the body have been affected by the prostate cancer i.e. whether the prostate cancer has spread to the bones.
PROSTATE CANCER STAGE AND SURVIVAL
The stage of prostate cancer describes how far the cancer has grown and spread. It is assessed by a mixture of DRE and CT/MRI scans.
This is very early prostate cancer which can only be seen under a microscope. At this stage the cancer would not cause any symptoms. Men with this stage are at low risk from their disease may not need any treatment but surveillance. The original cause of a prostate cancer problem can be difficult to diagnose.
This is early prostate cancer but is now big enough to be felt by a doctor on DRE. This may still not have caused any symptoms. This is most often cured if treatment is undertaken at this stage and about 70% of men are still alive after 5 years i.e. average length of survival from diagnosis is well over 5 years.
This is locally advanced prostate cancer which has started to extend and invade outside of the prostate gland. This stage would often cause bladder symptoms in men. By this stage in the disease the chance of cure with treatments is reduced however survival is often around five years.
This is more advanced prostate cancer which invades the structures around the gland. At this stage there are often already secondaries e.g. bone metastases. If the disease has spread it is usually incurable but may be controlled for some time. The average survival is between 1 and 3 years.
PREDICTING SURVIVAL IN PROSTATE CANCER
Doctors use a combination of risk factors to predict the behaviour of prostate cancer but cancers do not always act as expected. The factors they consider include the cancer stage (see above), the age of the patient, the PSA level and how quickly it is rising, and the Gleason Score. The Gleason score is a marker of how aggressive the cancer looks under the microscope and how much of the gland is affected by cancer.
Adrian Jones writes on several forms of cancer. Further information is available on his websites dealing with prostate cancer and colon cancer. You may reprint this if you include this credit.