Enhancing Prostate Tumor Biobanking Reliability with Improved Sampling Technique and Histological Characterization

Summary

This protocol describes a method for facilitating the collection of samples from radical prostatectomy specimens. The goal is to map, characterize, and micro-macro dissect tissue samples from the specimens based on anatomopathological criteria before storing them in a Biobank.

Abstract

Acquiring fresh and well-characterized tumor tissue samples is critical for conducting high-quality "omics" studies. However, it can be particularly challenging in the context of prostate cancer (PC) due to the unique nature of this organ and the high heterogeneity associated with this tumor. On the other hand, histopathologically characterizing samples before their storage without causing significant tissue alterations is also an intriguing challenge. In this context, we present a new method for acquiring, mapping, characterizing, and micro-dissecting resected prostate tissue based on anatomopathological criteria.

Unlike previously published protocols, this method reduces the time required for histopathological analysis of the prostate specimen without compromising its structure, which is crucial for assessing surgical margins. Furthermore, it enables the delineation and micro-macro dissection of fresh prostate tissue samples, with a focus on histological tumor areas defined by pathological criteria such as Gleason score, precursor lesions (high-grade prostatic intraepithelial neoplasia - PIN), and inflammatory lesions (prostatitis). These samples are then stored in a Biobank for subsequent research analyses.

Introduction

Prostate cancer (PC) is the 2^nd most frequent cancer in men and the 5^th leading cause of death worldwide¹. Patient treatment and prognosis depend on the staging and grading (Gleason score) of the tumor, as evidenced by the higher 5-year survival rates of localized and low-grade tumors (Gleason grade 6) (99%) compared to high Gleason grades and metastatic tumors (31%)².

PC local relapse and treatment failure have been linked to the characteristic high genetic intratumor heterogeneity of this tumor type³. Additionally, PC is considered to be a multif....

Protocol

This method was developed through collaborative efforts involving different clinical services (Urology, Pathology, and the La Fe Hospital Biobank). The study was conducted in compliance with institutional, national, and international guidelines for human welfare, and it received approval from the Ethics Committee for Biomedical Research at the Instituto de Investigación Sanitaria Hospital Universitario y Politécnico La Fe (Valencia, Spain). All samples were stored at the La Fe Hospital Biobank (PT13/0010/0026). The overall procedure is detailed in Figure 1.

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Discussion

In any research study, obtaining quality samples is an essential requirement to reduce systematic biases and obtain reliable results²². Therefore, control of preanalytical variables such as the temperature at which samples are processed and stored, the time elapsed from sample collection to storage, the use of sterilized materials, or the effects that the addition of preservatives or other additives can have on samples must be considered in any protocol involving biological samples. Not only is th.......

Materials

Name	Company	Catalog Number	Comments
Cadiere forceps	Intuitive	PN1052082-US 10/2021	Part number: 471049. 18 uses.
Conventional slides	Knittel Glass	2021	Ground/ Frosted end
Cryostat microtome	Thermo Fisher Scientific	---	Criostato CryoStar NX50
Cryotubes	Greiner Bio-One GmbH	Ref.: 122280.	CRYO S. PP, with screw cap, sterile.
Da Vinci surgical system	Intuitive	PN1052082-US 10/2021	XI model
Dissection instruments	Bayer	---	Two tweezers and a surgical blade
DPX Eukitt	Medizin- und Labortechnik GmbH	6.00.01.0001.06.01.01
Eosin	Agilent	157252
Fenestrated bipolar forceps	Intuitive	PN1052082-US 10/2021	Part number: 471205. 14 lives.
Force bipolar	Intuitive	PN1052082-US 10/2021	Part number: 471405. 12 uses.
Freezers	Thermo Scientific		MODEL 907. -80 ºC
Hematoxylin	Agilent	157251
Inmunohistochemistry Slides	Agilent-Dako	K802021-2
Large needle driver	Intuitive	PN1052082-US 10/2021	Part number: 471006. 15 uses.
Maryland bipolar forceps	Intuitive	PN1052082-US 10/2021	Part number: 471172. 14 uses.
Microscope	Olympus	---	Olympus cx40
Microtome blades	PFM Medical	a35
Monopolar curved scissors	Intuitive	PN1052082-US 10/2021	Part number: 470179. 10 uses.
OCT compound	NEG-50	LOT.117340
PlusSpeed S Single-use Biopsy Device with beveled tip	Peter Pflugbeil GmbH	PSS-1825-S
ProGasp forceps	Intuitive	PN1052082-US 10/2021	Part number: 471093. 18 uses.
Sample holder Disc	Davidson Cryo Chuck. BradleyProducts		30 mm
Tissue ink	Pelikan	2021	Ink 4001 brilliant black (301168)
Xylol	Quimipur	Ref. 169