Impact of Autonomic Nerve Invasion on Biochemical Recurrence for Intermediate Risk T3a Prostate Cancer With Negative Surgical Margins After Radical Prostatectomy

Abstract

OBJECTIVETo assess the impact of autonomic nerve invasion (ANI) on subsequent biochemical recurrence (BCR) or early adjuvant therapy in the patients with extraprostatic spread (EPS) and negative margins after radical prostatectomy (RP). METHODSA total of 218 men with EPS (T3a) and negative margins were identified who underwent radical prostatectomy in Western Australia from January 2014 to December 2016. The t-test, Pearson chi-square test and Kaplan-Meier method with the log-rank test were used to evaluate differences between the ANI and non-ANI. Univariate and multivariable Cox proportional hazard regression models were applied to assess the impact of these parameters on BCR or early treatment and a model calibration was performed by the internal validation method. RESULTSANI group had a significant higher incidence in BCR or early adjuvant therapy compared to non-ANI group (hazard ratio 1.94, 95% CI 1.12-3.37, p=0.02). Further analyses showed that ANI was significantly associated with BCR or early adjuvant therapy (hazard ratio 3.03, 95% CI 1.28-7.15, p=0.01) in intermediate risk cases (Gleason sum (GS)=7, i.e. International Society of Urological Pathology (ISUP) groups 2/3) but not in high risk group (GS≥8/ISUP 4/5). CONCLUSIONFor the patients with EPS (T3a) and negative margins, ANI significantly and independently increases the chances of BCR or early adjuvant therapy for intermediate risk disease (GS=7/ISUP 2/3) but it is not an independent predictor for high risk disease (GS≥8/ISUP 4/5). This provides a simple cost effective method to further stratify margin negative intermediate risk T3a prostate cancer.