Long-term utility of adjuvant hormonal and radiation therapy for patients with seminal vesicle invasion at radical prostatectomy

Objective: To investigate the long-term utility of adjuvant therapy after radical prostatectomy (RP) for prostate cancer with seminal vesicle invasion (SVI; pT3b), as the published data are conflicting. Patients and Methods: Patients with SVI during RP and pelvic lymph node dissection at two major referral centres from 1986 to 2014 were included. Kaplan–Meier analyses and multivariable Cox regressions were used to determine if adjuvant radiotherapy (aRT) and adjuvant hormonal therapy (aHT) were predictors of biochemical recurrence (BCR), cancer-specific mortality (CSM) and overall mortality (OM). Subset analyses were performed for pN0 patients and pN+ patients. Results: Overall, 3 279 patients with prostate cancer and SVI were included with a median follow-up of 148 months. Considering the whole SVI population, 1 387 (42%) received no adjuvant therapy, 1 179 (36%) received aHT, 461 (14.1%) received aRT, while 252 (7.7%) received both aHT and aRT. The 10-year BCR, CSM, and OM rates were 64%, 14%, and 27%, respectively. In the overall population, aRT and aHT were predictors of BCR, CSM and OM (all P < 0.04). When only pT3bN0 patients were considered, aHT was a significant multivariate predictor of BCR [hazard ratio (HR) 0.50, P < 0.001), CSM (HR 0.62, P = 0.01) and OM (HR 0.75, P = 0.004). Conversely, aRT was not associated with survival outcomes (all P > 0.05). When only the subgroup pT3bN+ was considered, the use of aRT was related to an improvement in CSM (HR 0.65, P = 0.03) and OM (HR 0.78, P = 0.03). Conclusions: aHT + aRT seems to be effective in pT3b patients. However, when stratified according to the presence of nodal metastases, aHT remains effective only in the node-negative subgroup, while aRT remains effective only in the node-positive subgroup. Further data including prospective trials are warranted to study the utility of adjuvant therapies in this setting.