Relationship between perineural tumor invasion on needle biopsy and radical prostatectomy capsular penetration in clinical stage B adenocarcinoma of the prostate

Abstract

We studied 302 needle biopsies for perineural invasion for sensitivity and specificity in predicting capsular penetration in subsequent radical prostatectomies. Perineural invasion was seen in 20% of needle biopsies, with a sensitivity of 27% and a specificity of 96% in predicting capsular penetration. By including tumor with a Gleason sum of 7 or greater or perineural invasion on needle biopsy as being predictive, sensitivity increased to 36% with a specificity of 94%. By restricting perineural invasion to cases with more than one nerve involved or a nerve involvement of a diameter 0.1 mm or greater, specificity increased to 97% and 99%, respectively, with sensitivity falling to 15% and 9%, respectively. Measuring perineural invasion on needle biopsy helps to identify capsular penetration and may help in planning nerve-sparing radical prostatectomy in the decision of whether to sacrifice part or all of the neurovascular bundle on the side of the biopsy.