Prostate Biopsy Processing

An Innovative Model for Reducing Cost, Decreasing Test Time, and Improving Diagnostic Material

Paari Murugan, MD; Dip Shukla; Jennifer Morocho, HTL; Deanne Smith, PA; Drew Sciacca, PA; Meghan Pickard, PA; Michelle Wahlsten, HTL; Ashley Gunderson, HTL; Badrinath Konety, MD; Mahmoud A. Khalifa, MD; Christopher Warlick, MD

Disclosures

Am J Clin Pathol. 2019;152(6):757-765. 

In This Article

Abstract and Introduction

Abstract

Objectives: Current protocols for processing multiple prostate biopsy cores per case are uneconomical and cumbersome. Tissue fragmentation and loss compromise cancer diagnosis. We sought to study an alternate method to improve processing and diagnosis of prostate cancer.

Methods: Two sets of sextant biopsy specimens from near-identical locations were obtained ex vivo from 48 prostate specimens. One set was processed in the standard fashion while the other was processed using the BxChip, a proprietary biomimetic matrix that accommodates six cores on a single chip. Parameters including grossing, embedding, sectioning and reading time, length of tissue, and degree of fragmentation were compared.

Results: A significant reduction (more than threefold) in preanalytical and analytical time was observed using the multiplex method. Nonlinear fragmentation was absent, in contrast to standard processing.

Conclusions: The BxChip reduced tissue fragmentation and increased efficiency of prostate biopsy diagnosis. It also resulted in overall cost savings and significantly increased tissue length.

Introduction

Prostate cancer is the second highest incident cancer in American men, with a rising rate over the past 60 years and an incidence of 164,690 cases in 2018.[1] A systematic transrectal ultrasound (TRUS)–guided prostate needle biopsy diagnosis is the cornerstone of risk stratification for appropriate patient management. The diagnosis involves evaluation of each mapped site for the presence of carcinoma, with subsequent quantification and Gleason score/Grade Group assignment. This information is critical for determining disease management strategy (active surveillance vs definitive management). In addition, when definitive therapy is indicated, it guides the extent of surgery as well as the type and dose of radiation therapy.[2]

Historically, six-core "sextant" biopsy specimens that sampled the bilateral base, middle, and apical regions were used to survey the prostate. Due to concerns of insufficient tissue for analysis and inaccurate cancer detection rates (CDRs), the current standard of care is to use a 10- to 14-core sampling technique that allows for more extensive investigation of the peripheral zone.[2–6] The extended biopsy protocol not only has increased the CDR but also has resulted in better concordance with the prostatectomy Gleason score. Increasing the number of cores beyond 12 (up to 24 cores for saturation biopsy specimens) has in general yielded modest improvements in the CDR[6] but may be warranted in patients with negative biopsy specimens and persistent suspicion of prostate cancer.[5]

Despite extended sampling protocols, prostate needle biopsy specimens can have a false-negative rate higher than 30%.[3] While sampling error, especially in cases with low cancer volume, is a significant reason for generating false-negative results, tissue loss due to poor orientation and fragmentation also plays a role. Tissue fragmentation, which can be present in nearly 30% of cases,[7] may distort cancer quantification and Gleason scoring with considerable treatment implications.[8]

Given the significance of the diagnostic results and the unique biopsy protocol, the submission, handling, and processing of prostate biopsy specimens assume a pivotal role. However, processing multiple sets of biopsy specimens per case remains uneconomical, time-consuming, and burdensome with concerns for diagnostic error. Our study demonstrates a potential solution that improves this practice, using a biopsy chip-facilitated multiplex approach.

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