High visibility press for the Bioreference 4KScore Test

Prostate cancer is one of the great dilemmas in current medicine.  While prostate cancer is often derided in public policy as an oversampled, overtested, and overtreated disease, nonetheless, it accounts for an astoundingly large proportion of all cancer deaths in men.  This paradox is not discussed prominently enough.   While the largest scale studies show modest population benefits of PSA screening, the real lesson should be that if testing were 25-50% more accurate and therapies were 25-50% more effectively chosen, this issue would be converted from a marginal benefit into a heavily weighted "win" for precision medicine against one of the major killers in cancer.   PSA and its historical performance curve should not be taken as a given, especially in an era of rapidly evolving diagnostics.  Replacing PSA should be taken as a mandate, as an urgent public health issue.  It would be like fixing a play by booting out a crappy actor and replacing him with a good one.

I have felt for at least a decade that Medicare's historical treatment of clinical chemistry pricing - that PSA was $20 and any test in the equivalent use category even if it had 2X better performance would be crosswalked to $20 - was an enormous embargo against creative investment and discovery.

The field has been rapidly moving forward, but only in the last 2-3 years.   Some tests are aimed at better characterization of screened patients, others at better decision making after an initial biopsy or even in the face of a rising PSA and a negative biopsy.

Last November, Forbes ran an article on the 4KScore test, which is being commercialized this year in the US (open access, here).   Today, Dark Daily also ran an article, here.

While not the 4KScore test as such, last month Lancet Oncology ran a study on the value of a multi marker prostate screening test with improved accuracy which includes the novel kallikrein markers commercialized now in 4KScore (Gronberg H et al., Lancet Oncol 16:1667, here; favorable OpEd by Lamb & Bratt, here.)  Lamb and Bratt make the same point I would make:

Screening for prostate cancer with prostate-specific antigen (PSA) reduces cancer mortality as effectively as screening for breast and colorectal cancer. Despite this, population-based screening with PSA is not recommended because of the high rates of false-positive test results, overdiagnosis, and overtreatment. The key to prostate cancer screening is finding ways to reduce these negative effects.

For a blog on an ill-conceived CMS metric proposal regarding PSA, here.