Dutch urologists say prostate cancer screening “cannot be justified”
Posted Aug 18 2010 12:00am
A new review by specialists from Erasmus University Medical Center, just published in Prostate Cancer and Prostatic Diseases, states categorically that mass, population-based screening for prostate cancer “cannot be justified yet in the context of a public health policy.”
This review, by van Leeuwen et al. , may be ruffling some feathers in Rotterdam specifically and in the Netherlands in general. Several of the leading participants in the European Randomized Screening Study for Prostate Cancer (ERSPC) came from Erasmus University Medical Center (EUMC) in Rotterdam, as do the authors of this specific article. Initial European reports along with statements from individual investigators had suggested that the results of the ERSPC did indeed justify widespread prostate cancer screening in Europe. However, the senior author of the current review, Dr. Chris Bangma, was a leading investigator in the ERSPC and is also the head of the Department of Urology at EUMC.
van Leewen et al. are careful to note in their review that widespread prostate cancer screening when carried out using PSA tests and digital rectal examinations does most certainly lead to a beneficial shift in the clinical stage at which patients are initially diagnosed and (based on the ERSPC data) does lead to a reduction in prostate cancer-specific mortality. However, they, as have others, note that there are major, problematic consequences of the widespread application of PSA testing:
A large increase in the cumulative incidence of prostate cancer
A significant cost associated with diagnosis and treatment of potentially indolent or at least not clinically significant disease
A significant impact on the quality of life of men who are arguably being “over-treated”
This review is not going to “sit well” with men who believe that prostate cancer screening “saved their lives.” Nor will it “sit well” with those members of the urology community that believe that a single death from prostate cancer represents medical failure.
The “New” Prostate Cancer InfoLink, however, has a different “take” on this issue.
In societies where there has never been any significant attempt to identify men at risk for prostate cancer, the PSA test and the DRE offer an excellent opportunity to identify many patients who might otherwise only be diagnosed with incurable metastatic prostate cancer. The data from the Göteborg screening study earlier this year clearly demonstrate this benefit in a highly defined community where there had been no prostate cancer screening prior to the initiation of that randomized study. It is likely that if one carried out a similar study in a city like Kano in Nigeria or Istanbul in Turkey today, one might still see similar result because the vast majority of men in those cities have probably never had a PSA test or a DRE. If you re-did the same study in Göteborg today, we suspect you would get a very different outcome!
Once initial, widespread PSA testing has identified bulky low-risk, intermediate-risk, and high-risk patients with relatively easily identified prostate cancer, the value of the PSA test in helping to identify patients with smaller amounts of low- and very low-risk prostate cancer (Gleason 6 disease, a PSA level < 10 ng/ml, clinical stage T2a or less, and probably no more than 2/12 positive biopsy cores) starts to become much less productive. We know that large numbers of these men (of the order of 30-40 percent) will live for 15-20 years with their disease without it ever reaching clinical significance, even if it is never treated.
If we are to be able to take the next step in eliminating the clinical risk for prostate cancer, we clearly need to be able to identify, early on and with great accuracy, the men who are going to have clinically progressive disease that may become metastatic, not just everyone with a few prostate cancer cells in their prostate. The PSA test and the DRE have no significant role to play in identifying these patients. They simply aren’t specific enough tests. We need to focus our attention on the potential to find new tests which do have that degree of specificity and selectivity.
We are forced by circumstance to do the best we can clinically with the PSA test for the time being, but we believe Bangma and his colleagues are correct, in the context of public health policy. If we are ever to radically change the morbidity and mortality associated with prostate cancer, we need a test that will accurately identify patients at risk of progressive disease long before it has the potential to become progressive and that needs a whole new way of testing for risk of such progressive forms of this disease.
For 30-40 percent of the men diagnosed in the USA today, at the time of diagnosis, their prostate cancer is a mild and chronic disorder that will never significantly impact their life. But aggressive treatment for such an indolent form of prostate cancer can and does significantly affect the quality of their lives. Even annual biopsies over several years in a rigorous active surveillance program have side effects. It is time for us to seriously rethink our priorities as an advocacy community. The men we need to find and diagnose early are those who will otherwise go on to have all of the problems of the men being diagnosed with locally advanced and metastatic disease prior to the advent of the PSA test. And we need to be able to manage and treat these men in ways that will eliminate their risk for progressive disease over time.