Does perineural invasion on prostate biopsy predict adverse prostatectomy outcomes?

UROLOGICAL SURVEY

Pathology

Does perineural invasion on prostate biopsy predict adverse prostatectomy outcomes?

Loeb S, Epstein JI, Humphreys EB, Walsh PC

James Buchanan Brady Urological Institute and the Department of Urology, Johns Hopkins Medical Institutions, Baltimore, MD, USA

BJU Int. 2009 Aug 19. [Epub ahead of print]

OBJECTIVE: To determine the relationship between perineural invasion (PNI) on prostate biopsy and radical prostatectomy (RP) outcomes in a contemporary RP series, as there is conflicting evidence on the prognostic significance of PNI in prostate needle biopsy specimens.

PATIENTS AND METHODS: From 2002 to 2007, 1256 men had RP by one surgeon. Multivariable logistic regression and Cox proportional hazards models were used to examine the relationship of PNI with pathological tumour features and biochemical progression, respectively, after adjusting for prostate-specific antigen level, clinical stage and biopsy Gleason score. Additional Cox models were used to examine the relationship between nerve-sparing and biochemical progression among men with PNI.

RESULTS: PNI was found in 188 (15%) patients, and was significantly associated with aggressive pathology and biochemical progression. On multivariate analysis, PNI was significantly associated with extraprostatic extension and seminal vesicle invasion (P < 0.001). Biochemical progression occurred in 10.5% of patients with PNI, vs 3.5% of those without PNI (unadjusted hazard ratio 3.12, 95% confidence interval 1.77-5.52, P < 0.001). However, PNI was not a significant independent predictor of biochemical progression on multivariate analysis. Finally, nerve-sparing did not adversely affect biochemical progression even among men with PNI.

CONCLUSION: PNI is an independent risk factor for aggressive pathology features and a non-independent risk factor for biochemical progression after RP. However, bilateral nerve-sparing surgery did not compromise the oncological outcomes for patients with PNI on biopsy.

Editorial Comment

Perineural invasion (PNI) on needle prostatic biopsies as a marker of extraprostatic extension has been controversial. In almost all studies, perineural invasion has been related to extraprostatic extension in univariate analysis but in only a few studies in multivariate analysis. The practical importance relates to the decision of whether to sacrifice part or all of the neurovascular bundle on the side of the biopsy with PNI in planning nerve-sparing radical prostatectomy.

Egan and Bostwick (1) found on univariate analysis that PNI on needle biopsy was significantly associated to extraprostatic extension and seminal vesicle invasion. On multivariate analysis, however, only preoperative PSA, proportion of the biopsy involved by cancer, and Gleason score were significant. Ukimura et al. (2) found that PNI on biopsy was a good predictor among others studied for extraprostatic extension on univariate analysis but not on multivariate analysis. In the study by Vargas et al. (3) PNI was not an independent predictor of extraprostatic extension when PSA was included.

D'Amico et al. (4) evaluated the clinical use of PNI at biopsy for predicting time to PSA failure following radical prostatectomy of 750 men with clinically localized or PSA detected prostate cancer. The presence of PNI on biopsy was not a significant predictor of PSA outcome following RP for patients in the intermediate or high risk group. O'Malley et al. (5) compared 78 biopsies with PNI with 78 matched controls without PNI and were unable to show that PNI on needle biopsy influences long-term tumor-free survival.

In the study surveyed, Loeb's et al. found that PNI is an independent risk factor for aggressive pathology features like extraprostatic extension and seminal vesicle invasion, and a non-independent risk factor for biochemical progression after radical prostatectomy. According to the authors, the findings support the routine reporting of PNI in biopsy pathology reports. They also concluded that nerve-sparing surgery did not adversely affect biochemical progression even among men with PNI.

Dr. Athanase Billis

Full-Professor of Pathology

State University of Campinas, Unicamp

Campinas, São Paulo, Brazil

E-mail: [e-mail]

• 1. Egan AJM, Bostwick DG: Prediction of extraprostatic extension of prostate cancer based on needle biopsy findings: Perineural invasion lacks significance on multivariate analysis. Am J Surg Pathol. 1997; 21: 1496-500.
• 2. Ukimura O, Troncoso P, Ramirez EI, Babaian RJ: Prostate cancer staging: correlation between ultrasound determined tumor contact length and pathologically confirmed extraprostatic extension. J Urol. 1988; 159: 1251-9.
• 3. Vargas SO, Jiroutek M, Welch WR, Nucci MR, D'Amico AV, Renshaw AA: Perineural invasion in prostate needle biopsy specimens. Correlation with extraprostatic extension at resection. Am J Clin Pathol. 1999; 111: 223-8.
• 4. D'Amico AV, Wu Y, Chen MH, Nash M, Renshaw AA, Richie JP: Perineural invasion as a predictor of biochemical outcome following radical prostatectomy for select men with clinically localized prostate cancer. J Urol. 2001; 165: 126-9.
• 5. O'Malley KJ, Pound CR, Walsh PC, Epstein JI, Partin AW: Influence of biopsy perinerual invasion on long-term biochemical disease-free survival after radical prostatectomy. Urology. 2002; 59: 85-90.

Publication Dates

• Publication in this collection
  07 Apr 2010
• Date of issue
  Feb 2010