Scientists are warning that the digital rectal examination (DRE) might not be a reliable way to check for prostate cancer in men. The DRE is when doctors use their finger to feel if the area around the man’s rectum is unusually large or has bumps and lumps on it. In some countries, like Germany, this is the only way they do screenings for prostate cancer.
A team of scientists from the German Cancer Research Center in Heidelberg did an experiment. It suggests that mammograms, a kind of test usually used to find breast cancer, might not be catching cancer at its earliest stages.
Last week, some scientists presented their research results about prostate cancer at an event called the European Association of Urology Annual Congress in Milan. These findings could help us detect the presence of prostate cancer earlier. Therefore, they are suggesting that we use different methods for routine testing instead.
Dr. Agne Krilaviciute, who works at DKFZ and wrote this study, said that prostate cancer is usually better treated if it’s detected early. But the study suggests that the way we’re currently testing people for prostate cancer (which is called a ‘DRE’) may not be good enough to find early cases.
The PROBASE trial was an experiment conducted in Germany where 46,495 men aged 45 years were involved over a period of five years from 2014-2019. During the trial, half of the participants received a blood test called Prostate-Specific Antigen (PSA) when first enrolled at age 45, while the other half waited until they turned 50 before getting tested with PSA tests. The health of the men was then monitored to see the effects of the testing.
In total, 6,537 men had to wait until they underwent a special medical check-up called DRE. Out of these men, only 57 of them needed further tests because the doctor was suspicious about something. Eventually, just 3 out of those 57 were diagnosed with cancer.
The doctors compared this method (the DRE) to other methods such as a PSA test and found that it detects cancer at a lower rate than the other methods.
Dr. Krilaviciute says that tests done with the DRE device usually gave wrong results in 99% of cases. But, a trial called PROBASE has shown that prostate cancer can be better detected by testing PSA at the age of 45 – this type of testing found four times as many cancers compared to the DRE tests.
Scientists think that the Digital Rectal Exam (DRE) may be missing some cancers in younger men because they can’t detect small changes in prostate tissue with their fingers. Also, certain types of cancer form in parts of the prostate where fingers can’t reach them.
Professor Peter Albers, an expert at Düsseldorf University and leader of the research team said, “Early stage cancer might not be big or hard enough to touch.”
The researchers did a study in which they used MRI scans to search for cancer in the prostate. They found that 80% of the cancers were located in areas that should be easy to feel with your finger. However, the standard method of testing for cancer, called DRE (Digital Rectal Exam) couldn’t detect those cancers.
Therefore, the researchers are suggesting that PSA tests and MRI scans should be used more often as part of cancer-screening procedures instead of just using DRE.
Professor Albers said that if a screening program isn’t doing its job, which is to find cancers early on, it’s not successful. We think that not only does the DRE (Digital Rectal Exam) method not help find cancer, but it may also stop some men from going to their screenings.
In Germany, when men between the ages of 45 and 50 are asked to join a screening program, only around 20% decide to do it. If researchers start using a test called the PSA Test instead, more people would likely join. This was discussed at an important medical meeting called EAU23 European Association of Urology Annual Congress.
