By Dr Dan Sperling, Interventional Radiologist specialising in Prostate
A balanced discussion of prostate cancer screening using the PSA blood test is posted on this website. It is written by Mr. Rick Popert, a Consultant Urological Surgeon. Mr. Popert describes the dilemma men face: the PSA blood test has been shown to reduce the mortality rate of prostate cancer (PCa) but at the price of a high rate of over-diagnosis and over-treatment. In turn, aggressive treatment of many low-risk PCa cases that were diagnosed because of a PSA result has left untold thousands of men with urinary or sexual side effects after treatment. In some instances, the harms have been permanent. Yes, lives were saved, but quality of life was impaired. To screen, or not to screen? That is a thorny question.
Pros and cons of the PSA test
Given the harms caused by PSA screening, Mr. Popert states that a policy decision was made: “there would be no prostate cancer screening programme in the UK.” At the same time, the UK’s national Prostate Cancer Risk Management Programme (PCRMP) empowers, “both patient and GP to consider the issues and implications of early prostate cancer diagnosis and treatment.” Each individual should discuss with his general practitioner (physician) the pros and cons of the PSA test in his personal situation.
Since prostate cancer has virtually no symptoms in its early stages, the PSA test is the most reasonable first step in early detection. In fact, prior to the PSA test launch in the mid-1990s, many PCa patients were diagnosed only after symptoms appeared—at which point, it was likely that the cancer had advanced to the point where cure was not possible. Thus, the PSA test has indeed saved lives, but the tendency has been to react to an elevated PSA by having an immediate needle biopsy. Historically, this is what led to the harms of over-diagnosis and over-treatment.
Newest data reinforces the value of PSA screening
Still, the merits of PSA screening can’t be denied. The latest evidence in favour of screening at regular intervals starting at age 50 (earlier depending on individual risk factors) comes from a large 20-year study out of Sweden. It involved 20,000 men who were randomly divided into two groups. Ten thousand men received PSA tests every two years, with biopsy triggered by elevated PSA results. The other ten thousand were not offered PSA tests. The reported results were as follows:
After 22 years' follow-up, approximately 300 men had died of prostate cancer. The risk was some 30 percent lower for men who had undergone screening in the program. Men at the highest risk of dying from prostate cancer were those whose screening started after age 60; men who were diagnosed after leaving the study (aged about 70 and over); and those who were invited, but did not participate at all.
Lowering the PCa mortality rate by 30% is compelling! If there is any doubt that the PSA test saves lives due to early detection, this should put that doubt to rest. But it still does not tell us how to avoid the harms that have been undeniably attributed to reacting abruptly to abnormally high PSA test results.
How to avoid overkill
Mr. Popert rightly makes the point that a single baseline PSA test at, say, age 50 is only a starting point for effective screening. Actually, the Swedish study found that the baseline PSA at participants’ entry point was somewhat predictive for future PCa diagnosis, but a single PSA test is insufficient information. As Mr. Robert notes, “Once they have had the test done it should be repeated regularly to confirm that it does not change significantly over time, the patient has effectively entered a prostate cancer screening programme.” This is very important. Experience teaches that if a man’s first PSA is normal, and he is told he does not have prostate cancer, he may be so relieved that his testing stops there. Thus, for screening to work effectively, PSA must be monitored at one- or two-year intervals over time.
Just as important, at the first sign of PSA elevating, don’t panic! A biopsy is still the only way to confirm a PCa diagnosis, but we now have three reasonable steps to take before rushing into it:
Step one:
Wait several weeks and repeat a PSA test. This rules out lab error or some transient disturbance of the prostate. If it’s still high, proceed to
Step two:
A specialized MRI scan of the prostate, which will reveal any area(s) that are suspicious for significant prostate. If found, proceed to
Step three:
A confirmatory MRI-guided targeted needle biopsy into the visibly suspicious area.
After these steps, if a diagnosis of prostate cancer is made, key information has now been gathered to help determine the treatment that best matches the disease. This information is the combined highest PSA result, the MRI-based revelation of the location and aggression level of the tumour, and the biopsy-proven nature of the prostate cancer cells. Based on these factors, is the tumour low-risk, intermediate-risk (favorable or unfavorable), or high-risk? These factors determine treatment choice, based on the nature of the disease and the patient’s preferences and lifestyle. If the disease is still contained in the prostate gland (has not begun to spread), here are general PCa management categories:
- For low-risk disease, the patient may be qualified for Active Surveillance, or a minimally invasive focal approach to destroy the tumor while sparing urinary and sexual function.
- For favourable intermediate-risk disease, depending on factors the patient may be qualified for a focal or partial gland treatment to minimize side effect risks, or a whole-gland treatment.
- For high-risk disease, a whole-gland treatment such as surgical removal or radiation, with or without additional hormone therapy.
Lifesaving and preserving quality of life
Of course, only a doctor can clinically determine which treatments are best suited for each patient. Following this pathway is not only lifesaving, it offers the greatest chance to preserve quality of life while controlling the cancer. If appropriately qualified, less invasive focal or partial gland treatments can offer good cancer control with less side effect risks than whole gland treatment. Most importantly, PSA screening can continue to save lives, while a pathway that includes MRI can prevent the harms of over-diagnosis and over-treatment.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you have health concerns or questions of a personal medical nature.
