Model suggests liquid biopsy improves prostate cancer outcomes, but that’s not the real world

Does the news release adequately discuss the costs of the intervention?

Not Satisfactory

Although a major aim of the study was to examine societal costs of employing this test, the actual cost of the test to an individual patient is nowhere to be found.  It appears to be in the hundreds of dollars, and there is no sign that Medicare is covering it as of yet.  The release notes that a number of US-based insurance companies have contracted to use the test.

Does the news release adequately explain/quantify the harms of the intervention?

Not Satisfactory

Although providing urine for the test involves little to no risk, choosing not to move forward with a biopsy as a result of the test does bring with it a risk of being wrong, should the cancer be aggressive (a false negative). The likelihood of that error would be an important piece of information.

The study cites a reference suggesting that the sensitivity for detecting high-risk cancers was 95.7%.

Does the news release seem to grasp the quality of the evidence?

Not Satisfactory

The researchers appear to have built a mathematical decision model to simulate survival and cost outcomes of two conditions: a prostate diagnosis aided by a traditional biopsy or, alternatively, the initial employment of the SelectMDx test to judge if a biopsy is recommended. The news release offers little in the way of explanation.

The release seems to gloss over the fact this is a modeling study. The author’s quote that the study demonstrated that using the test improves health outcomes and lowers healthcare costs is misleading. The modeling results only suggest that it might.  We don’t know how the test would be applied or interpreted in real-world decision making so any actual benefits remain speculative.

Does the news release identify funding sources & disclose conflicts of interest?

Not Satisfactory

Neither element shows up in the text.  Since the news release comes from the company MDxHealth, which is marketing the test, one might assume that the company paid for the study.  But the text of the research report suggests otherwise, indicating funding from the American Cancer Society and a foundation focused on urological research. That would have been a useful addition to the release.

Does the news release compare the new approach with existing alternatives?

Not Satisfactory

Although the text does a good job of explaining the risks of a prostate biopsy, it does not make clear that the gains found in the study stem from a comparison of employing the SelectMDx test to determine if a particular prostate cancer warrants further diagnostic efforts versus using a PSA test or ultrasound to make such a judgment.

The traditional alternative is actually to make biopsy decisions based on PSA alone–not ultrasound (which is used for the biopsy).  However, MRI is increasingly being used to identify potential high-risk tumors and guide guide biopsy decisions: MRI-targeted or standard biopsy for prostate-cancer diagnosis.  Kasivsisvanathan V, et al. N Engl J Med 2018; 378:1767.

Does the news release establish the true novelty of the approach?

Not Satisfactory

The lead correctly identifies the research as a “new” study but fails to acknowledge the publication of a very similar piece of research more than a year earlier that generated almost identical results in Europe.