At this year’s American Urological Association annual meeting in Orlando, FL, there were numerous courses that offer continuing education credits for physicians. One of the courses was directed by Dr. J. Stephen Jones who, for five years, served as Chair of the Urology Department at the Cleveland Clinic. He is very well respected in the world of prostate cancer.
As part of his course entitled “Prostate Cancer Diagnostics: PSA, Prostate Biopsy and Beyond,” he identified the criteria of a good screening test:
- Sensitivity (% of actual positives that are identified as such)
- Specificity (% of actual negatives that are identified as such)
- Non-invasive and safe
- Detects a common condition
- Detects a harmful condition
- Detects a condition that has an effective treatment, which works better in the pre-clinical phase than after the condition is clinically detected
- Benefits outweigh the harms
When it comes to the PSA blood test as a means of screening for prostate cancer, Dr. Jones gives it mixed reviews. The obvious up-sides of the blood test are that it is non-invasive, safe, and detects something going on in the prostate. So far, so good.
However, rating PSA as a prostate cancer detection tool begins to drop after that. It correctly points to prostate cancer only about 75% of the time; it is even worse at identifying true negatives (ruling out prostate cancer) only up to 35% of the time at best. Does it detect a harmful condition (aggressive cancer)? Well, yes, but it also detects low-risk cancers that can perhaps be simply watched. And because tests tend to beget more tests, many men with an elevated PSA are rushed into biopsy—which is not without risks—and if the biopsy proves positive, they are rushed into treatments that may be “overkill” in certain cases. Thus, its cost/benefits value is questionable.
Likewise, Dr. Jones pointed out that the cost-effectiveness of widespread PSA screening is also debated, since it often leads to inconclusive biopsies that must be repeated, or eventually to an expensive invasive treatment with more expenses related to managing treatment side effects.
As for the PSA detecting a condition for which there are effective treatments, it is accurate to say that thanks to early detection, far fewer men die of prostate cancer than 30 years ago—but how many have paid a price for diminished quality of life because they were treated too soon or too aggressively?
The era of PSA screening is evolving to a new age of correlating biomarkers, genomics and imaging to give a clear idea of whether or not a man needs a biopsy. At our Center, we are confident that imaging in particular has become so sophisticated that we see it as a highly sensitive and specific, non-invasive, cost-effective way to avoid unnecessary biopsies, guide biopsies and certain treatments, and follow patients after focal treatment. In our world, imaging is a fantastic way to go beyond less-than-ideal screening methods.