Ceramic foam plates: a new tool for processing fresh radical prostatectomy specimens

A New Technique in Fresh Prostate Cancer Tissue Biobanking Based on MRI-Transrectal Ultrasound Fusion Biopsy

OBJECTIVE

To present and validate a new technique for biobanking fresh-frozen prostate cancer tissue based on MRI-transrectal ultrasound fusion biopsy.

MATERIALS AND METHODS

From August 2014 to August 2016, patients with elevated levels of PSA and at least 1 suspicious lesion on MRI were invited to this study. Each MRI-suspicious lesion was biopsied repeatedly for at least 2 cores in the same location. These repeated cores were labelled A/A', B/B', etc. The A/B cores were submitted for histologic assessment, and the corresponding A'/B' cores were stored in an -80°C freezer for biobanking. Sixty biobanked samples were processed for histologic assessment to compare their pathologic parameters with their corresponding paraffin samples. Another 20 biobanked samples were processed for RNA quality evaluation.

RESULTS

Fifty-six of the 60 selected banking samples matched their corresponding paraffin samples for benign vs malignant diagnosis, leading an overall concordance rate of 93.3%. There was no significant difference between banking samples and the corresponding paraffin samples in cancer percentage and Gleason score. The RNA Integrity Number value ranged from 6.8 to 9.3 (mean 7.89).

CONCLUSION

The current study demonstrates that the histologic identity of the banked prostate biopsy sample can be accurately predicted by its corresponding paraffin samples. MRI-TRUS fusion biopsy based biobanking method is highly efficient, timesaving, and has high quality tissues both at the histologic and RNA integrity levels.

Protocols for Tissue Microarrays in Prostate Cancer Studies

Tissue microarray (TMA) technology is a method for high-throughput analysis of tissue biomarkers, commonly used in translational cancer research. TMAs allow performing a variety of in situ applications on hundreds of tissue samples simultaneously using the same protocols as for conventional slides. Thereby, precious material from patient samples remains largely preserved while costs in resources and time in laboratory processing decrease. Therefore, a TMA is a powerful tool to identify and study biomarkers that may have a potential diagnostic, prognostic, and predictive value. Depending on the research question, there are different types of TMAs, such as progression TMA, outcome TMA, and tumor heterogeneity TMA. Since the first introduction of the TMA method almost 20 years ago, most laboratories used manual tissue arrayers for manufacturing. Nowadays, automatic or semiautomatic devices are commercially available, which largely facilitates the technical construction. However, preparatory work remains the most time-consuming part in preparing TMAs. This chapter focuses on issues involved in design and construction of prostate cancer TMAs.

A novel technique for biobanking of large sections of radical prostatectomy specimens

AIMS

Harvesting of unfixed tissue from radical prostatectomy specimens for research purposes is challenging. Many prostate cancers cannot be identified at gross inspection, and this tumour is notoriously multifocal and heterogeneous. We aimed to develop a technique to allow detailed topographic analysis and the sampling of a sufficient amount of tumour without jeopardising clinical reporting.

METHODS AND RESULTS

A custom-made double-bladed knife was utilised for cutting a 4-mm-thick horizontal section of the prostate. The slices were split into segments that were frozen in gel, cryosections were cut, and RNA integrity numbers (RINs) were analysed. Sections were cut from all blocks of 20 cases, and the cutting time was monitored. Slides were scanned, and the slices were digitally reconstructed. Cutting frozen sections of an entire slice took 79-253 min (mean 162 min). Tumour was detected in frozen sections of 85% (17/20) of cases and in 46% (72/155) of blocks. The morphological quality was determined to be excellent, and RIN values were high (mean 8.9).

CONCLUSIONS

This novel protocol for biobanking of fresh tissue from prostatectomy specimens provides sufficient tumour material for research purposes, while also enabling reporting of histopathology. The harvesting of a full tissue slice facilitates studies of tumour multifocality and heterogeneity.