An Important Part of Prostate Cancer Screening
T he digital rectal exam (DRE) should always be included as part of prostate cancer screening.
It is an important predictor for prostate cancer, and in particular, aggressive prostate cancer.
The DRE sometimes picks up cancers before a PSA test indicates concern, especially in aggressive cancers where the PSA level can be low precisely because the cancer is so aggressive.
Also, results of a DRE can give some indication of the prognosis and therefore assist in treatment decisions.
Some people think that if a PSA comes back low, then the DRE isn’t necessary. That view is not correct. The DRE can detect some cancers before they cause a rise in PSA. Conversely, PSA picks up many cancers where the DRE is negative. Thus, the two tests go hand in hand.
In one *study (Catalona), 14% of the prostate cancer cases were detected solely on the basis of abnormalities found during digital rectal exams.
When comparing the history of those men (who were diagnosed because of an abnormal DRE with no indication of an abnormal PSA) with men who were diagnosed because of both abnormal PSA results and abnormal DRE, the 10-year **progression-free survival and ***cancer-specific survival after treatment by radical prostatectomy were significantly better for the men diagnosed based upon DRE alone.
In other words, if the DRE is abnormal; waiting to recommend a biopsy until the PSA is abnormal may lead to worse outcomes in some cases.
The DRE is not a substitute for the PSA test – which, so far, is the best method for early detection of prostate cancer. But the DRE has a place and a purpose in early detection that only it provides.
Clearly, the PSA test and the DRE are better together because they provide complementary information.
Accordingly, PSA tests and DRE should both be done as part of annual prostate cancer screening exams.
*Stacy Loeb, MD and William J. Catalona, MD are interpreting and discussing a study (Gosselaar) that reported on results of DRE in men from a Rotterdam portion of the European Randomized Study of Screening for Prostate Cancer. Then, adding to that information, they described previously published outcomes of radical prostatectomy from patients diagnosed through a large cancer screening study (Catalona) of 36,000 men. Both studies added to a considerable body of evidence supporting a role for DRE in early detection of prostate cancer.
The **10-year progression-free survival (83% vs. 63%) and ***cancer-specific survival (99% vs. 96%) after radical prostatectomy were significantly higher for men diagnosed exclusively due to an abnormality in DRE than for those in whom both PSA and DRE were abnormal.
