A combination of screening technologies like digital rectal exam along with PSA blood test and MRI is the most effective in detecting prostate cancer.
- A digital rectal exam alone is insufficient for detecting prostate cancer
- Combining the rectal digital examination with another screening method, such as a blood test for prostate-specific antigen (PSA) is effective
- Although digital rectal exams are affordable and may be performed during a doctor’s visit, experts agree that many men prefer not to have the intrusive exam
Rectal Examination is Not Enough for Detecting Early Stage Prostate Cancer
Nevertheless, new research from scientists at the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ) in Heidelberg reveals that the technique may overlook many tumours in their early stages. According to the researchers, the findings, which were presented today at the European Association of Urology Annual Conference in Milan, could have ramifications for the early diagnosis of prostate cancer. They are advocating for the employment of other testing technologies in routine screening instead.“One of the main reasons for screening for prostate cancer is to detect it in patients as early as possible as this can lead to better outcomes from treatment,” said Dr Agne Krilaviciute, a researcher at DKFZ and lead author of the study. “But our study suggests that the DRE is simply not sensitive enough to detect those early-stage cancers.”
The PROBASE trial is a multicenter German prostate cancer screening study conducted at four university sites (TU Munich, Hannover, Heidelberg, and Düsseldorf) that enrolled 46,495 men aged 45 between 2014 and 2019. Following the screening, the men had follow-up appointments to assess their health. Half of the trial participants were offered a PSA blood test immediately at age 45, while the other half were originally provided DRE with delayed PSA screening at age 50.
In the end, 6,537 men in the delayed screening group underwent DRE, with only 57 of them referred for a follow-up biopsy due to worrisome results. Only three people were discovered to have cancer.
PSA Blood Test More Accurate In Detecting Prostate Cancer
When compared to other means of detection, such as a PSA test, the detection rate utilizing DRE was significantly lower, according to Dr Krilaviciute.“The DRE was giving a negative result in 99% of cases and even those that were deemed to be suspicious had a low detection rate,” says Dr Krilaviciute. “Results we’ve seen from the PROBASE trial show that PSA testing at the age of 45 detected four times more prostate cancers.”
Reasons for the Failure of Rectal Examination in the Detection of Prostate Cancer
The researchers believe that one of the reasons the DRE may be failing to detect malignancies, particularly in younger men, is because changes in prostate tissue may be too subtle to detect with a finger. Furthermore, some tumors develop in areas of the prostate that are difficult to reach with a finger.“Early-stage cancer may not have the size and stiffness to be palpable,” said Professor Peter Albers, a urologist at Düsseldorf University who was the senior author of the study.
“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.”
Use PSA Blood Test and MRI in Prostate Cancer Screening Programs
Instead of DRE, the researchers are now advocating for the widespread use of PSA tests and MRI scans as part of screening programs.“If a screening program aims to pick up cancers as early as possible and the current screening tool isn’t doing that job, then that is a fundamental failure of that approach,” said Professor Albers. “We speculate in our paper that not only is the DRE not useful for detecting cancer, but it may also be one reason why people don’t come to screening visits - the examination probably puts a lot of men off.
“In Germany, for example, the participation rate is less than 20% in the screening programme for men 45 to 50 years. If we were to offer PSA testing instead, more of them might be willing to come.”
Source-Medindia