Specimen Provenance Testing Identifies Contamination That Affects Molecular Prognostic Assay Results in Prostate Cancer Biopsy Specimens

To determine if tissue contamination in histologic specimens can significantly affect the results of prognostic molecular markers that are routinely used as confirmatory tests to safely assign appropriate candidates to prostate cancer active surveillance protocols.

This study evaluates 2,134 cases from a single, large urology practice that were successfully tested for DNA specimen provenance verification using short tandem repeat analysis for the presence of a significant level of contaminating DNA. After removal of the contamination, five of the samples were retested, and the results of the molecular diagnostic test were compared.

49 of the 2,134 cases (2.3%) sent for DNA provenance analysis were found to possess significant levels of contamination. Of these 49 cases, seven of them were resent for a repeat molecular diagnostic test after being decontaminated. Five of these prostate cancer specimens had sufficient tissue and RNA to give a more accurate cell cycle progression (CCP) score. The average absolute change in these patient's CCP scores was 0.48, with a low of a 0.1-unit and a high of a 1.0-unit difference. These changes in CCP scores are significant enough to cause meaningful alterations in a patient's calculated 10-year mortality rate, as defined by their combined risk score (CRS).

DNA contamination in unstained tissue sections sent for prognostic prostate cancer molecular diagnostic testing occurs on 2.3% of cases, and can be of a magnitude that affects the results and subsequent clinical decision of appropriateness for active surveillance.

Urology. 2018 Feb 21 [Epub ahead of print]

Lathem Wojno, Caitlyn Minutella, Donald Moylan, Arla Bush, Kirk Wojno

University of California Los Angeles, CA., Comprehensive Urology a Division of Michigan Healthcare Professionals, MI., Strand Diagnostics, IN., Comprehensive Urology a Division of Michigan Healthcare Professionals, MI. Electronic address: .