Digital Rectal Exam May Not Detect Prostate Cancer

Researchers in Germany found that digital rectal exams are less effective than the PSA test for detecting early-stage prostate cancer in younger men.

The digital rectal exam (DRE) is a test doctors use to detect abnormal changes in the prostate that may indicate prostate cancer. It’s a simple procedure in which the doctor uses a gloved, lubricated finger to feel the prostate from inside a male’s rectum.

Despite being quick and simple, many males dread the digital rectal exam and would rather avoid the procedure altogether.

Now, luckily for those apprehensive men, researchers have found compelling evidence to suggest that the DRE may not be the most effective method to detect prostate cancer in its early stages.

The scientists presented their research on March 9th at the European Association of Urology Annual Congress in Milan.

To examine the effectiveness of the DRE, scientists involved in the PROBASE trial, coordinated at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) in Heidelberg, recruited 46,495 males aged 45 enrolled in the trial between 2014 and 2019.

Half of the participants, aged 45, were offered prostate-specific antigen (PSA) — which measures PSA in the blood — and the other half were offered DRE at age 45 with delayed PSA screening at age 50.

In the group screened with a PSA test at 45, results showed that 89.2% fell into the low, 9.3% into intermediate, and 1.5% (about 344), fell into the high risk category for prostate cancer.

After the scientists repeated the PSA test in the high-risk group, they confirmed that 186 were indeed at high-risk. Of those individuals, 120 underwent a prostate biopsy, and 48 were diagnosed with prostate cancer.

In the group offered a DRE at 45 and delayed PSA tests at 50, only 6,537 went ahead with a DRE. Among those participants, 57 were referred for a biopsy due to suspicious findings. However, only two individuals were diagnosed with prostate cancer.

The scientists suggest their results show that DRE is not accurate or reliable enough to detect early-stage prostate cancer. Therefore, they are calling for screening programs to focus on using PSA testing and MRI scans instead of DRE.

The researchers also say that DREs might not be an accurate screening method because changes in prostate tissue may be challenging to detect with a finger. Moreover, the location of some cancers may make them difficult to access during a DRE.

In a news release, Professor Peter Albers, M.D., a urologist at Düsseldorf University and senior study author, says, "early-stage cancer may not have the size and stiffness to be palpable."

However, Albers adds, "separate analysis that used MRI scans before biopsies to locate cancers in the prostate showed that about 80% of these are in an area that should be easy to reach with a finger and still cancers were not detectable by DRE."

Yet, according to the news release, DRE is still the primary prostate cancer screening method used in some countries, such as in Germany.

The U.S. Preventative Services Task Force and the American Academy of Family Physicians no longer recommend DRE as a prostate cancer screening test in the United States. In addition, the organizations also say that healthcare providers should not screen for prostate cancer using the PSA test until after discussing the risks and benefits with their patient.

While prostate cancer is a serious disease, most men won't die after diagnosis. Early detection and prevention are essential and with this new research, optimal testing can lead to quicker treatment.