(123) Postoperative Changes of Serum Total Testosterone Levels in Patients with Prostate Cancer After Robot-Assisted Radical Prostatectomy

Abstract

Abstract Introduction Although a relationship between prostate cancer and serum total testosterone (TT) has been studied, previous evidences were contradictory. Although a relationship between prostate cancer and serum total testosterone (TT) in terms of cancer biology as well as sexual function has been studied, previous evidences were contradictory and not organized very well. Objective We investigated the changes in TT levels after robot-assisted radical prostatectomy (RARP) for prostate cancer as a prospective surveillance. Methods From July 2015 to January 2022, 290 patients out of 1,343 prostate biopsies performed in our hospital underwent RARP with a diagnosis of localized prostate cancer. TT measurements were performed at 6:00 early morning on admission to all patients for biopsy. Of these, we studied 76 patients whose TT values have been measured during postoperative follow-up. TT values were measured 1 month after RARP, every 3 months until 36 months thereafter, and every 6 to 12 months thereafter for up to 72 months postoperatively. Results The median and quartile of age, serum PSA and TT (pre-TT) values at biopsy of the 76 patients were 69 years (64–72 years), 7.47 ng/mL (5.65–12.74 ng/mL) and 4.03 ng/mL (2.96–4.83 ng/mL), respectively. There was no significant correlation between age and pre-TT values (p = 0.21). RARP was performed an average of 2.9 months after biopsy. The median follow-up period was 43 months (31–60 months). PSA recurrence was observed in 18 patients (23.7%), with 3- and 5-year PSA non-recurrence rates of 77.4% and 74.9%, respectively. There was no significant difference in pre-TT values between patients with or without PSA recurrence (p = 0.107). Analysis of TT values at each observation period after RARP showed relative increase by an average of 23.4% (after 1 month) to 41.6% (after 36 months) when compared with pre-TT values. Further analysis of dividing 76 patients into 2 groups by a pre-TT value of 3.00 ng/mL showed that only in the low pre-TT group (pre-TT < 3.00 ng/mL: 21 cases, 27.6%), the rate of increase in TT values over pre-TT was significantly higher than that in the normal pre-TT group (pre-TT ≥ 3.00 ng/mL: 55 cases, 72.4%) at each observation period up to 72 months after RARP except 33 and 54 months Conclusions The transition of postoperative TT values in the patients who underwent RARP continued to show a significant increase at each observation period only in the group with low TT values preoperatively, suggesting that biochemical hypogonadism may have been presumably caused by prostate cancer-bearing conditions preoperatively in these patients with low TT values. Disclosure No.