JU INSIGHT Risk Stratification by Quantification of Perineural Cancer Invasion on Prostate Needle Core Biopsy
By: Yuki Teramoto, MD, PhD, University of Rochester Medical Center, New York; Ying Wang, MD, PhD, University of Rochester Medical Center, New York; Hiroshi Miyamoto, MD, PhD, University of Rochester Medical Center, New York | Posted on: 25 Oct 2023
Teramoto Y, Wang Y, Miyamoto H. Risk stratification by quantification of perineural cancer invasion on prostate needle core biopsy: should it be counted?. J Urol. 2023;210(4):639-648.
Study Need and Importance
The presence of perineural invasion (PNI) by prostate cancer, particularly on biopsy, has been implicated in adverse pathology, including extraprostatic extension, and resultant unfavorable oncologic outcomes. By contrast, the prognostic role of PNI quantification on prostate biopsy remains poorly understood. Notably, pathologists do not routinely count the number of PNI foci in prostate cancer specimens, and a subset of them even report its detection on biopsy as a case-level summary.
What We Found
In each biopsy specimen from 724 men who had subsequently undergone radical prostatectomy, up to 10 PNI foci were identified. The prognosis was found to be comparable between those with 0 vs 1 PNI (P = .9), whereas the risk of biochemical recurrence in those with 2 (P < .001) or ≥2 (P < .001) PNI was significantly higher, compared to those with 1 PNI (see Figure). There was no significant difference in recurrence-free survival between those with 2 vs 3 (P = .3) or ≥3 (P = .3) PNI. Interestingly, patients with multifocal PNI detected in only 1 biopsy site had a significantly higher risk of recurrence than those with single PNI (P < .001). Additionally, >1 PNI per 10-mm tumor (vs ≤1 PNI; P = .008) was associated with worse recurrence-free survival. Meanwhile, the inclusion of multifocal PNI in the CAPRA (Cancer of the Prostate Risk Assessment) score considerably improved postoperative risk stratification.
The limitations of our study included its retrospective nature from a single institution and analysis of only radical prostatectomy cases with no adjuvant therapy prior to recurrence. Furthermore, we did not assess the impact of PNI counting on targeted biopsy being increasingly used.
Interpretations for Patient Care
PNI quantification on prostate biopsy likely provides useful information for a more accurate prediction of postoperative patient outcomes. Pathologists may then need to report the presence of PNI in every biopsy site or at least specify single vs multifocal PNI.