Robotic assisted radical prostatectomy accelerates postoperative stress recovery: Final results of a contemporary prospective study assessing pathophysiology of cortisol peri-operative kinetics in prostate cancer surgery

Objective: To investigate the effects of prostate cancer (PCa) surgery on the stress system and to identify potential independent factors associating with stress recovery. Methods: The design of the study was prospective and PCa surgery included robot assisted radical prostatectomy (RARP) or retropubic radical prostatectomy (RRP). Between February 2013 to December 2014, 315 consecutive patients were evaluated. The effects of PCa surgery on the stress system were measured by cortisol serum levels before and after surgery on post-operative day (POD) 0, 1, 3, 5 and 45. Cortisol variations in the population and subpopulation (RARP vs. RRP) of patients were investigated by statistical methods. Factors associating with stress recovery were assessed by simple linear regression (SLR) and multiple linear regression (MLR) analysis. Results: RARP was performed in 75.9% of cases. In the patient population, there were wide serum cortisol perioperative variations. PCa surgery triggered the stress system which immediately (POD 0) responded by cortisol overproduction which induced the negative feedback mechanism that started on POD 1, continued on POD 3, was still ongoing on POD 5 and completely settled on POD 45 (stress recovery). In the subpopulation of patients, significantly lower cortisol serum levels were detected on POD 3-5 in RARP cases in whom cortisol levels were close to preoperative levels (stress recovery) on POD 5. Independent predictive factors of serum cortisol on POD 5 (stress recovery) were preoperative cortisol (p = 0.02), cortisol levels on POD 3 (p < 0.0001) and RARP (p = 0.03) in which the association was negative (stress recovery faster than RRP). Conclusion: Our study shows that PCa surgery immediately (POD 0) triggers the stress system which respond by overproduction of cortisol which induces the negative feedback mechanism that starts on POD 1, is still ongoing on POD 5, but is completely settled on POD 45. Moreover, after surgical trauma, our study gives evidence that the RARP procedure associates with stress recovery faster than RRP. Further confirmatory studies are required.