SIUrO best practice recommendations to optimize BRCA 1/2 gene testing from DNA extracted from bone biopsy in mCRPC patients (BRCA Optimal Bone Biopsy Procedure: BOP)

Abstract

The main guidelines and recommendations for the implementation of the BRCA1/2 somatic test do not focus on the clinical application of predictive testing on bone metastases, a frequent condition in metastatic prostate cancer, by analyzing the critical issues encountered by laboratory practice. Our goal is to produce a document (protocol) deriving from a multidisciplinary team approach to obtain high quality nucleic acids from biopsy of bone metastases. This document aims to compose an operational check-list of three phases: the pre-analytical phase concerns tumor cellularity, tissue processing, sample preservation (blood/FFPE), fixation and staining, but above all the decalcification process, the most critical phase because of its key role in allowing the extraction of somatic DNA with a good yield and high quality. The analytical phase involves the preparation of the libraries that can be analyzed in various NGS genetic sequencing platforms and with various bioinformatics software for the interpretation of sequence variants. Finally, the post-analytical phase that allows to report the variants of the BRCA1/2 genes in a clear and usable way to the clinician who will use these data to manage cancer therapy with PARP Inhibitors.

Keywords: BRCA; Bone biopsy; Bone metastasis; Next-generation sequencing; Optimization; PARP inhibitor; Prostate cancer.