Prototype of Prostate Cancer Diagnostic Test May Decrease Repeat Biopsies

A prototype prostate cancer diagnostic test may aid urologists in determining patients who have a true negative biopsy result from patients who may suffer from occult cancer undetected by prostate biopsy and histopathologic review. Should a larger study confirm these preliminary findings, this test could spare 30% of men who require testing for cancer a repeat biopsy following a negative biopsy.

According to a new study, a prototype prostate cancer diagnostic test may aid urologists in determining patients who have a true negative biopsy result from patients who may suffer from occult cancer undetected by prostate biopsy and histopathologic review. Should a larger study confirm these preliminary findings, this test could spare 30% of men who require testing for cancer a repeat biopsy following a negative biopsy.

Called the Prostate ConfirmMDx, the test identifies epigenetic alterations in specific prostate cancer-related genes.

The prospective study, led by Alan Partin, MD, PhD, of Johns Hopkins, was performed at three US urology centers: Johns Hopkins University, Walter Reed National Military Medical Center Bethesda, and Cleveland Clinic.

The researchers focused on 86 men who received an initial histologically negative prostate biopsy, but still had characteristics that indicated a high cancer risk. They determined DNA methylation of the glutathione-S-transferase P1 (GSTP1) and adenomatous polyposis coli (APC) genes via tissue from the initial negative biopsy, which was then compared with histology of the repeat biopsy.

The researchers found that the relative negative predictive value of APC in comparison to the primary outcome of the study, GSTP1, was 96%.

"APC methylation provided a very high negative predictive value with a low percentage of false-negatives,” reported the authors in their article, “in the first prospective study to evaluate performance of DNA methylation markers in a clinical cohort of men undergoing repeat biopsy.”

A larger, more in-depth study has been recommended by the authors.

Currently, MDxHealth is performing a validation trial utilizing its Prostate ConfirmMDx assay.

These findings were published online on November 11th, 2011 in BJU International .