KLK3 and metastatic neoplasm: In metastatic disease progression, the protective effect became stronger after being adjusted by the PSA value at the RT start, number of lymph nodes, and the PET imaging method, with HR having improved from 0.54 (95% CI: 0.25–1.17) to 0.39 (95% CI: 0.17–0.90), as well as the p-value from 0.1 to 0.03.