Objective: To analyze the oncological outcomes of “at-risk” men with Prostate cancer (PC) following radical prostatectomy who were managed without versus with adjuvant radiation therapy (ART). Additionally a cost comparison will be conducted between radiotherapy and observation groups.
Patients and Methods: 1500 men who underwent robot-assisted radical prostatectomy (RP) and no adjuvant radiation therapy at UC Irvine constitute the comparator group, (Observation group) of men who had a RP for prostate cancer and managed without ART. Observation patients with no PSA follow-up or who had pre-operative treatment were excluded. All data was prospectively collected and retrospectively analyzed in the observation group. Two comparator groups of men who received ART were selected from two randomized control trials (SWOG 8794 and EORTC 22911) and separately analyzed against the UCI observation group. Outcomes assessed in the analysis include Biochemical recurrence (BCR), metastasis-free survival, prostate cancer specific mortality (PCSM) and Overall survival. Kaplan-Meier analysis was utilized to compare outcomes with previous randomized control trials. Medicare reimbursement rates were used to estimate cost of secondary interventions.
Results: 364 patients were selected by SWOG 8794 inclusion criteria. After adjusting by proportion of Gleason score and pathological stage, the UCI observation cohort had non-inferior outcomes with metastasis-free and overall survival rate than the trial. Also, analysis in 368 men who were qualified by EORTC 22911 inclusion criteria demonstrated the similar non-inferior results in overall survival and cancer-specific survival rate. Cost per patient in the RCTs was $26,343 for ART groups and $7,874 in the RCT control groups after considering primary, secondary complication treatment expenses versus UCI only $3,544 per patient.
Conclusion: Radiation-naïve patients had non-inferior oncological outcomes as compared to men receiving ART. The expense of ART is three to seven times higher than radiation-naïve men. Decision of early radiation treatment should be re-evaluated because of the lack of mortality benefit, side effects of radiotherapy and cost.
