Patients who underwent RARP between October 2010 and December 2017 at our department for prostate cancer (stages cT1–cT3 N0 M0) were included in the present study. All patients consented after being fully informed in accordance with the ethics committee at our institution. All study data were analyzed retrospectively. Age, body mass index (BMI), prostate-specific antigen (PSA), prostate volume (PV), clinical stage, Gleason score (GS), and operative results were recorded. The International Prostate Symptom Score (IPSS), the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), and QOL index were evaluated before RARP and at 1, 3, 6, 12, 24, 36, 48, 60 months after RARP. Regarding sexual function, the International Index of Erectile Function (IIEF-EF) was used to evaluate before RARP and at 1, 3, 6, 12, 24,36, 48, 60 months after RARP.
However, Japanese patients are known to be less sexually active than other races. In order to evaluate by sexual function, the IIEF-EF parameters were examined separately for Q1 (How often were you able to get an erection during sexual activity?) less than 2 and Q1 greater than 2. In addition, to see the effect of nerve sparing, cases with Q1 less than 2 and greater than 2 with nerve sparing were also examined.
Data are presented as median value and interquartile range (IQR). Values of p<0.05 were considered significant. Statistical analyses were performed using EZR, which is a modified version of R Commander.