Prospective selective embedding of radical prostatectomy specimens is not inferior to full embedding regarding established and new prognostic parameters.

Abstract

The histopathological examination of radical prostatectomy specimens is essential for assessing critical tumor characteristics, including stage, grade, and margins, all of which impact patient prognosis. However, the extent of embedding the prostate has long been a subject of debate, with some advocating partial/selective embedding and others favoring complete embedding. This study establishes a standardized and time-efficient protocol for processing radical prostatectomy specimens with limited embedding while maintaining diagnostic accuracy. Two hundred twenty-six prostatectomy specimens were analyzed, and the results of a highly standardized selective embedding protocol, systematically embedding the apex, the base, the transition to the seminal vesicles, and selected horizontal sections, were compared with full embedding as the gold standard. Non-inferiority testing was conducted by one-sided binomial tests and Pearson-Clopper confidence intervals. Selective embedding provided consistent and accurate diagnostic information with up to 90-98% concordance in pT, margins, ISUP-grade groups, and presence of IDC-P and cribriform tumor growth. In summary, this study establishes an economical standardized protocol for selective embedding of radical prostatectomy specimens with only minimal loss of information.