KLK3 and neoplasm: In addition to tumor burden, several characteristics, including the duration from mPC to mCRPC, PSA value before using enzalutamide, ECOG performance status, prior chemotherapy history, skeletal-related events, and some laboratory data (hemoglobin, percent of segment neutrophil, platelets count, alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), and calcium) were associated with progression-free survival in the univariable analysis.