Should reporting of peri-neural invasion and extra prostatic extension be mandatory in prostate cancer biopsies? correlation with outcome in biopsy cases treated conservatively.

// Amar S. Ahmad 1 , Vishnu Parameshwaran 2 , Luis Beltran 2 , Gabrielle Fisher 1 , Bernard V. North 1 , David Greenberg 3 , Geraldine Soosay 4 , Henrik Moller 5 , Peter Scardino 6 , Jack Cuzick 1 and Daniel M. Berney 2 on behalf of the Transatlantic Prostate Group 1 UK Center for Cancer Prevention, Wolfson Institute of Preventive Medicine, Queen Mary University of London, London, UK 2 Department of Molecular Oncology, Barts Cancer Institute Queen Mary University of London, London, UK 3 National Cancer Registration Service (Eastern Office), Public Health England, Cambridge, UK 4 Department of Pathology, Queen’s Hospital, Romford, Essex, UK 5 Cancer Epidemiology and Population Health, King's College London, London, UK 6 Department of Urology, Memorial Sloan-Kettering Cancer Center, New York, NY, USA Correspondence to: Daniel M. Berney, email: D.Berney@bartshealth.nhs.uk Keywords: prostate cancer; perineural invasion; Gleason score; survival analysis Received: August 24, 2017      Accepted: March 15, 2018      Published: April 17, 2018 ABSTRACT The identification of perineural invasion (PNI) and extraprostatic extension (ECE) in prostate cancer (PC) biopsies is time consuming and can be difficult. Although this is required information in many datasets, there is little evidence on their effect on outcome in patients treated conservatively. Cases of PC were identified from three cancer registries in the UK from men with clinically localized prostate cancer diagnosed by needle biopsy from 1990–2003. The endpoint was prostate cancer death (DOD). Patients treated radically within 6 months, those with objective evidence of metastases or who had prior hormone therapy were excluded. Follow-up was through cancer registries up until 2012. Deaths were divided into those from PC and those from other causes, according to WHO criteria. 988 biopsy cases (6522 biopsy cores) were centrally reviewed by three uropathologists and assigned a Gleason score and Grade Group (GG). The presence of both PNI and ECE was recorded. Of 988 patients, PNI was present in 288 (DOD = 75) and ECE in 23 (DOD = 5). On univariable analysis PNI was highly significantly associated with DOD (hazard ratio [HR] 2.28, 95% CI: 1.68, 3.1, log-rank test p -value = 4.8 × 10 –8 ), but ECE was not (log-rank test p -value = 0.334). On multivariable analysis with GG, serum PSA (per 10%), clinical stage and extent of disease (per 10%), PNI lost significance (HR 1.16, 95% CI: 0.83, 1.63, likelihood ratio test p -value = 0.371). The utility of routinely examining prostate biopsies for ECE and PNI is doubtful as it is not independently associated with higher grade, stage or prognosis.