KLK3 and prostate cancer: Consequently, based on these results, the duration of LHRHa administration in our study was acceptable; the resumption of LHRHa due to PSA failure after radical prostatectomy for prostatic cancer without distant metastasis at a PSA of approximately 2.0 ng/mL is desirable; and it is thought to be important to continue LHRHa administration sufficiently until the level of PSA decreases to 0.01–0.02 ng/mL.