Diagnosing prostate cancer through a £225 urine test

An interview with Dr. Jan Groen, CEO, MDxHealth conducted by April Cashin-Garbutt, MA (Cantab)

Can you please give an overview of the £225 urine test MDxHealth developed to diagnose prostate cancer? How does the test work?

This test, which we have branded SelectMDx for Prostate Cancer, came with the acquisition of a company in the Netherlands called NovioGendix. They developed a prototype assay, so they did most of the heavy lifting in terms of discovering the two specific biomarkers that are currently in the product. These biomarkers are tuned towards the detection of what I call clinically significant prostate cancer.

It is a very simple, straightforward molecular diagnostic test. Like most of the molecular diagnostic tests that are currently on the market, it is a PCR (polymerase chain reaction) based assay. After acquiring the company, we immediately started to commercialize this product and brand it as SelectMDx® for Prostate Cancer.

It works by detecting RNA in the urine of a man that has an elevated PSA level. A man is only eligible for the SelectMDx test, once the PSA level is elevated.

The standard of care is slightly different in the United States than it is in Europe. In the United States, they use the PSA (prostate specific antigen) test as a screening test. It is a very simple $15 blood test that detects circulation of the protein, PSA, in the bloodstream. If that’s elevated, which is defined as higher than 3mg/mL, it indicates that something may be wrong with the prostate. It wouldn’t necessarily mean the man has prostate cancer; it could be an infection of the prostate or prostatitis, for example.

Elevated PSA levels does not mean you have prostate cancer, an enlarged prostate, for example, can also result in an increased PSA level. In contrast to the United States where PSA screening is commonplace, in Europe, if a patient has clinical symptoms or is worried something might be wrong with his prostate, he will first visit his GP (General Practitioner) to discuss his symptoms. The GP could consider measuring the PSA and if it’s elevated, the patient might receive a referral to see the urologist. Based on increasing PSA levels combined with other clinical manifestation, the urologist might decide to biopsy the patient. The biopsy of a man’s prostate is the standard of care to confirm a prostate cancer diagnosis.

Today, we know that the vast majority of men with an elevated PSA level undergo a biopsy procedure, but only a small portion of them will be diagnosed with prostate cancer, based on the histopathology results. The biopsy procedure, which is a rectal procedure, involves 12-cores being taken by needle from the prostate, which are sent to a pathology lab for review.

The pathologist analyses the samples using a microscope and checks for the absence or presence of cancer cells. When cancer cells are present, it’s obvious, but if there are no cancer cells present, it may be that a needle has missed cancer, so to speak, or it could be that there is no prostate cancer in play whatsoever.

To put it into perspective, I’ll give you some statistics. Each year, 1.3 million biopsies are carried out in the United States and based on the standard of care (the prostate biopsy procedure), approximately 220,000 men are diagnosed with prostate cancer. It’s an invasive procedure and if only about 220,000 of the 1.3 million suspected cases do in fact have prostate cancer, that means that based on microscopic analysis, nearly 1.1 million men undergo a biopsy procedure when no cancer was present. By definition, that would not mean no cancer was present; however, it could be that they were just not able to detect it using the microscope.

Now, instead of patients with elevated PSA levels going straight to a biopsy procedure, we can provide our SelectMDx liquid biopsy test first. It’s a non-invasive test because it only entails collection of a urine sample, which we then test for the absence or presence of two prostate cancer-specific biomarkers in the urine.

When those biomarkers are present, you are most likely dealing with a high-grade disease − a clinical significant form of prostate cancer. If the biomarkers are absent, there is most likely no cancer or the patient is likely to have indolent prostate cancer.

It’s an early stratification test, to identify the patients that most likely are dealing with aggressive prostate cancer.

How accurate is SelectMDx and how has it been validated?

The test had been validated in a multi-center trial of more than a thousand patients before we launched the product to the market. Patients with elevated PSA levels, with and without a history of prostate cancer were included in these studies.

The negative predictive value of the…