SCREENING FOR PROSTATE CANCER
Why do doctors screen for prostate cancer?
Many men will develop clinical prostate cancer in their lifetimes. This figure is about ten percent. Often the disease does not cause any symptoms until it has spread beyond the prostate gland. This is called metastatic disease. Currently we have no modality of treatment that can cure a patient with metastatic prostate cancer. Local disease on the other hand can often be treated successfully. Clinical disease can occur at anytime usually after the age of forty years. Its absence does not mean it cannot occur at some later date in the future.
In the 1980’s it became the trend to start looking for prostate cancer before the disease had spread elsewhere. This meant that men had to be educated to come forward at an earlier age to be examined and assessed. If early disease was detected, local treatment was recommended with the view to curing the patient. Obviously where no disease is found, these men are reassured and asked to return at a later date for further evaluation.
Currently, international guidelines recommend that screening should be offered annually, starting at fifty years of age, to men who have a life expectancy of at least ten years. Men in a high risk group should start screening from forty years of age.
Screening has changed radically how prostate cancer manifests. The majority of patients in the first world environment today are discovered at the early preclinical phase before symptoms have begun. It is of interest however that doctors still do not know if this has altered the overall survival from the disease. More time needs to elapse so that more mortality statistics can be collected before that judgement can be made. Of relevance to South Africa is that we do not know the true prevalence and outcome of the disease in black South Africans. A lot more education and provision of access to screening facilities is required to bring black folk into the fold.
Who should screen me for prostate cancer?
This is a highly specialized task. Only an urologist is qualified to provide this kind of assessment. It takes several years to gather enough skill and experience to make a competent assessment of a prostate gland. The family physician should ask his patients if they have had a screen and encourage them to go for one if not.
What will happen at my screening visit?
Firstly a thorough history will be taken. You should be prepared to answer questions concerning your family medical history; your voiding and sexual symptoms; as well as give a detailed account of any past and current medical problems and medications that you may be taking.
Secondly a general examination is performed so that the urologist can obtain an idea of your general state of health. This is followed by a focused urological examination. Three tests are essential in this assessment. Namely a digital rectal exam; a rectal sonar and a PSA blood test.
The digital rectal exam (DRE) involves careful palpation of the prostate gland through the anal passage. From this test the urologist gains an impression of the prostate size, shape and consistency. Hard areas, nodules and lumps if present can be felt. The surgeon’s finger can only feel the rearward half of the prostate gland but this is where most prostate tumours occur.
The procedure is not usually painful unless there is local pathology such as anal fissures or thrombosed piles.
The transrectal ultrasound (TRUS) is a test whereby a probe is carefully placed in the rectum against the prostate gland. It produces pictures using sound waves of the interior of the prostate gland. TRUS can pick up tumours deep within the gland that cannot be felt by DRE. The TRUS is also used for prostate biopsies.
The prostate specific antigen (PSA) blood test. Vast amounts of literature have been spawned concerning this blood test. Confusion and information overload abound. Some people develop what I call a PSA psychosis. Their whole existence revolves around knowing about PSA and getting their most recent results. A separate page on this web site is devoted to Facts and
Myths concerning PSA. Suffice to say here, it is an important tool in the assessment of prostate disease BUT it cannot be considered diagnostic especially in isolation of a full prostate assessment. Never have a PSA test alone. Normal PSA tests will miss a large percentage of cancers. Prostate cancer can never be excluded because a PSA test is the so-called normal range.
If any of the above tests or a combination thereof provides grounds for suspicion of prostate cancer, then the urologist will advise the patient to have a prostate biopsy.
What is a prostate biopsy?
Prostate biopsy provides prostate tissue for a pathologist to examine under the microscope. Examining tissue obtained from a prostate gland is the ONLY way to make a diagnosis of prostate cancer. Other procedures or operations on prostate glands also provide tissue for the pathologist and sometimes an unsuspected cancer is diagnosed this way. It is important to stress that the operation did not cause a prostate cancer. Having an operation on the prostate gland will not cause a cancer to develop in the future.
In a prostate biopsy, a thin hollow needle is fired into the prostate gland at various locations including any suspicious areas. This is done under ultrasound guidance (TRUS). The hollow needle obtains cores of prostatic tissue analogous to how a geologist obtains rock core samples. The procedure varies from uncomfortable to downright painful. You can discuss with urologist beforehand whether you want the procedure awake or asleep.
Especially with smaller cancers, the more cores taken the higher the chance of picking up a tumour at the initial biopsy. It is not uncommon for men to undergo more than one biopsy procedure when a cancer is not initially detected but the suspicion of its presence remains. Discuss with your urologist if he uses the twelve core prostate biopsy which is becoming the accepted standard.
Antibiotic is routinely administered prior to a prostate biopsy. Remember to inform your urologist of any allergies! This is to prevent infection within the gland. However about one percent of patients will still get a prostatitis. If you feel unwell soon after a prostate biopsy, this should be reported immediately to your urologist. Symptoms include fever, chills, nausea, lower back pain, extreme difficulty urinating and intense pain on passing urine.
It is normal to see blood in the urine and stool for a short period after the procedure. Most bleeding has ceased within forty eight hours. If you have a very heavy bleed or persistent bleeding this should be reported to your doctor. The semen will also be discoloured after a prostate biopsy. It may only clear after you have had sex about six times after the biopsy. If you are taking an anticoagulants such as Warfarin, Aspirin, Ecotrin, Plavix or Heparin you must inform the urologist prior to any prostate biopsy. Though uncommon, major bleeds from prostate biopsies can occur.
What happens after the Biopsy?
After the biopsy, the urologist will ask the patient to return after about three days to discus the result. A discussion will take place according to the findings. Either the biopsy is negative, sometimes uncertain or positive. If the biopsy is negative then you will followed up according to the degree of suspicion that a lesion is present. If the result is equivocal then a second biopsy will probably be scheduled. If the result confirms a prostate cancer is present, then the talk will centre on how it will be managed.