Introduction:

Experiments performed on tissue procured from human genitourinary cancer resection specimens have been critical to understand cancer biology and for developing targeted therapies. Our objective was to evaluate the accuracy of a tissue procurement protocol utilizing multiparametric magnetic resonance imaging (mpMRI) to guide procurement; we hope to make this method reproducible for any member of a research team to perform.

Methods:

Fourteen men who underwent robotic radical prostatectomy were included. Patients were sequentially included in our procurement cohort if they had an mpMRI prior to procurement. Men with solely Gleason (Gl) 6 (Grade Group 1) or who had a single focus of Gleason 3+4 (Grade Group 2) were excluded. All patients were informed of the procurement protocol and provided written informed consent to the Penn Bio Bank to be part of this QI improvement protocol.

mpMRI images were reviewed on the back table once the specimen had been extracted from the body. The largest & highest PIRADS lesion was selected for procurement, if a palpable lesion was noted and correlated to the mpMRI we targeted the palpable area. A cognitive fusion ex vivo biopsy was performed guided by mpMRI imaging using a Bard MAX-CORE biopsy instrument. Additional cores were reviewed and given pathologic scores and concordance with final pathology was evaluated.  

Results:

Final Gleason pathology was as follows: 3+4 in 6/14 (43%), 4+3 in 2/14 (14%), 4+5 in 5/14 (36%), and post treatment (meaning extensive treatment effect from androgen deprivation therapy affecting histopathology) in 1/14 (7%). A median of five research cores per lesion were collected. Seventy one percent of overall procurement were positive for any prostate cancer (PCa) [29% had no PCa present]. The median percentage of cancer in the sum of cores for one lesion was 54%. In only 21% of our procured cores did the dominant Gleason score for the whole organ’s final path correlate with the dominant Gleason score in our procurement specimens.

Conclusion:

The urologist’s role in tissue based experimental research is critical. A standardized approach for fresh PCa tissue procurement at the time of prostatectomy yielded any PCa in 71% of specimens, with roughly half of any procurement yielding PCa suitable for experiments. The concordance rate of final pathology was 21%.

Care should be taken when interpreting results from studies that do not clearly describe their procurement methodology as the samples may not reflect final pathology, especially when taken as fresh specimens. Further work is needed to define which lesions are best suited for reproducible fresh PCa procurement.

Funding: N/a