A prognostic test for low risk of progression post-surgery
Posted Apr 30 2010 12:00am
IRIS Molecular Diagnostics has submitted an application to the U.S. Food and Drug Administration to market a prostate cancer prognostic test called NADiA® ProsVue™. The company says that this test is “designed to help physicians identify patients at low risk of cancer recurrence post radical prostatectomy.”
This test is apparently based on the company’s NADiA (Nucleic Acid Detection Immunoassay) technology, which can be used for the ultrasensitive detection of specific proteins. However, there is no information in the company media release about exactly what proteins are being detected by the NADiA ProsVue test.
We are told that the application for approval of the test is based on a study using data and specimens from 300 patients followed for at least 8 years after radical prostatectomy. Apparently 228/300 patients were stable after surgery (we assume this to mean they had no sign of biochemical relapse); by contrast the remaining 72 patients had recurrent disease.
We are somewhat worried, however, by the fact that data from 25,000 patients had to be examined to find 392 patients whose available data and specimens “qualified” them for potential inclusion in this retrospective data analysis. That looks like a worrisome level of selectivity for data analysis. It is also entirely unclear what criteria were being used to determine whether the test was actually able to predict post-surgical outcome. However, the centers involved in this study included Duke University, Memorial Sloan-Kettering Cancer Center, Eastern Virginia Medical Center, and the University of Washington all of which are highly reputable institutions.
It is clear from the company media release that IRIS Molecular Diagnostics has made two prior attempts to get this prognostic test approved. This might suggest to the skeptical observer that the clinical value of the test is still open to some question. However, “The data generated from the retrospective clinical study will be presented at upcoming scientific meetings by the clinical investigators.” We will need to see what these data look like when they become publicly available. There does not currently appear to be a presentation about this test scheduled for the upcoming annual meeting of the American Urological Association.
Additional information about this test and other prognostic tests for prostate cancer appear on Genomeweb. The great unanswered question, of course, is whether any of these new tests are actually better than monitoring your PSA and your PSA doubling time.