Prostate cancer (PCa) is the most common tumor in Germany and also the number one cause of death from cancer in men. The transrectal biopsy performed to diagnose PCa is associated with infection risks, among other things. Now, however, a way may have been found to put PCa diagnostics on a safer and more comfortable footing.
In order to diagnose a cancer of the prostate and to distinguish it from benign prostatic hyperplasia (BPH), which is also quite common, the transrectal punch biopsy is currently used as standard. However, this diagnostic procedure is not only painful, but also carries various other risks like bacterial infections.
Researchers at the University of Witten/Herdecke, however, have now developed the basis for a new procedure in which small genetic material fragments from the urine can be used to distinguish between the two diseases (BPH or PCa).
In this new method, microRNAs (miRNA) and piwi-interacting RNAs (piRNAs) are extracted from small amounts of a urine sample and amplified by PCR. MicroRNAs are short molecules of genetic information that are not translated into proteins themselves. Instead, they regulate the realisation of gene information.
With the help of so-called next-generation sequencing, such RNA fragments can be read quickly and precisely in specialised laboratories. Important for diagnostics: The RNA segments seem to be involved in the development and progression of PCa.
The researchers analysed more than 2,500 such small RNAs for their study and discovered a pattern. Bioinformatic machine learning algorithms then independently sifted through the data thus obtained. "If the composition of microRNAs in the urine changes, this apparently speaks for or against prostate cancer," explained Lukas Markert, one of the lead researchers of this project. "In addition to the PSA value and the biopsy, the microRNA analysis from the urine could be established as an additional diagnostic criterion in urology," said Markert and colleagues in their current work.
The study presented here is a very interesting approach to simplifying prostate cancer diagnostics in the future and making it less invasive for patients. In addition to the PSA value, the microRNA from the urine may help to distinguish between benign and malignant prostate changes at an early stage.
In the case of a positive finding in both the PSA test and the miRNA diagnostic, the patient will still not be able to avoid a punch biopsy. The tissue sample is still indispensable for the pathological findings as well as the staging of the prostate carcinoma and thus decisive for therapy.
However, it may become easier to decide whether a transrectal punch biopsy is indicated or not, so the development of the new additive miRNA diagnostic procedure may further reduce the risk of overtreatment.
Markert L et al, Small RNAs as biomarkers to differentiate benign and malignant prostate diseases: an alternative for transrectal punch biopsy of the prostate? PLoS ONE 16(3): e0247930. https://doi.org/10.1371/journal.pone.0247930