Integrity of prostatic tissue for molecular analysis after robotic-assisted laparoscopic and open prostatectomy

The warm ischemia time of tissue before fixation for pathologic analysis has been linked to changes in cell morphology and nucleic acid and protein integrity. Robotic-assisted laparoscopic prostatectomy (RALP) results in longer warm ischemia times than open radical retropubic prostatectomy. To assess the effect of longer ischemia times on biomolecular integrity, we analyzed DNA, RNA and protein collected from robotic and open prostatectomy specimens.

We examined 22 consecutive RALP (n = 11) and open radical retropubic prostatectomy (n = 11) specimens after hematoxylin-eosin staining by light microscopy. To assess protein integrity, immunohistochemical staining for p63, E-cadherin, and AE1/AE3 was performed. DNA was assessed by gel analysis. An RNA integrity score was determined by microfluidic capillary electrophoresis and calculated according to the electropherogram findings and simulated gel view. Finally, epithelial cells were cultured on collagen-coated plates.

No differences in clinicopathologic characteristics were found between the two groups, with the exception of a significantly longer warm ischemia time during RALP (82 +/- 23 minutes) compared with open radical retropubic prostatectomy (23 +/- 2 minutes; P <0.001). Tissue integrity was suitable for the assessment of pathologic grade and stage for all samples. Protein and DNA analyses demonstrated no evidence of degradation in any samples. No significant differences in the RNA integrity scores were demonstrated between the surgical approaches. Prostate epithelial cells were cultured successfully in 66% of the RALP specimens.

RALP, although it involves additional exposure to warm ischemia, does not significantly affect the histopathologic characteristics or biomolecular integrity of the specimen. Provided a rapid response occurs for tissue banking after specimen removal, molecular research studies using prostatic tissue harvested by way of RALP appear feasible.