Clinical Significance of Perineural Invasion by Prostate Cancer Detected on Needle Core Biopsy

Unilateral vs Bilateral Involvement

Yuki Teramoto, MD; Numbereye Numbere, MD; Ying Wang, MD, PhD; Hiroshi Miyamoto, MD, PhD


Am J Clin Pathol. 2023;159(2):116-119. 

In This Article

Abstract and Introduction


Objectives: The clinical impact of the laterality of perineural invasion (PNI) by prostate cancer remains poorly understood. We herein compared radical prostatectomy (RP) findings and long-term oncologic outcomes in patients with prostate cancer with PNI in two prostate biopsy (PBx) sites.

Methods: We retrospectively assessed 170 consecutive patients undergoing systematic sextant PBx where PNI had been detected in two of six PBx sites, followed by RP.

Results: PNI occurred unilaterally in 140 (82.4%) cases and bilaterally in 30 (17.6%) cases. Compared with unilateral PNI, bilateral PNI was significantly associated with a higher number of cancer-positive sites and longer total tumor length on PBx. However, there were no significant differences in RP findings, including tumor grade/stage and tumor volume, between unilateral and bilateral PNI cohorts. Kaplan-Meier analysis revealed that patients with bilateral PNI had a significantly higher risk of disease progression after RP than those with unilateral PNI (P = .038). In multivariate analysis, bilateral PNI (vs unilateral PNI) showed significance for progression (hazard ratio, 2.281; P = .023).

Conclusions: In PBx specimens exhibiting PNI in two sextant sites, bilateral PNI was found to be associated with poorer prognosis as an independent predictor but not worse histopathologic features in RP specimens compared with unilateral PNI.


Histopathologic features of prostate cancer on needle core biopsy, even those other than Gleason score/Grade Group (GG), often provide critical information for optimal patient care. Of these, perineural invasion (PNI) by prostate cancer has been associated with adverse pathology, particularly extraprostatic extension.[1,2] The presence of PNI on biopsy has also been implicated as a key prognosticator in patients with prostate cancer undergoing radical prostatectomy or radiotherapy.[2–5] By contrast, little is known about the role of PNI quantitation on prostate biopsy. In our recent study involving systematic biopsy specimens exhibiting PNI in one to six sextant sites, multisite PNI, compared with a single PNI site, was found to be associated with significantly poorer prognosis after radical prostatectomy.[6] Nonetheless, the clinical impact of PNI laterality (ie, right or left only vs both sides) remains to be determined. The present study aimed to assess radical prostatectomy findings and long-term oncologic outcomes in men with prostate cancer whose sextant biopsy specimens had exhibited PNI in two of the sites.