Method for sampling tissue for research which preserves pathological data in radical prostatectomy

Abstract

Background: The diagnosis and treatment of prostate cancer is a challenging global healthcare issue requiring significant molecular research. Such research frequently utilizes fresh frozen human tissue which needs to be obtained in a manner acceptable to the pathologist which does not compromise tumor diagnosis or staging.

Methods: Radical prostatectomy specimens were handled in a standardized method before being sliced fresh. Leaving the margins intact, multiple cylindrical cores were removed using a large skin punch and the sites were marked on a prostate map. The cylindrical cores were placed onto individual, pre-numbered foil squares and snap frozen in liquid nitrogen. Prostate maps were aligned with formalin-fixed paraffin embedded hematoxylin and eosin stained sections of the sampled slice to select tumor regions. Frozen tumor tissue cylinders were processed taking one section for hematoxylin and eosin staining, 6 µm × 50 µm sections for molecular studies and a further section for hematoxylin and eosin staining. This was performed for the length of the cylinder.

Results: A total of 150 prostates have been removed and sliced using this technique. Pathological assessment remained uncompromised. Using the sequential hematoxylin and eosin stained frozen sections, cellularity could be monitored closely in tissues processed for research. The yield of RNA and DNA extracted was high (tumor mean 2.4 µg (RNA) and 12.7 ng per 300 µm tissue) and of high quality (mean tumor RIN 5.9).

Conclusions: This novel, rapid sampling and processing method provides high quality tissue for research without compromising pathology.