KLK3 and breast cancer: Ultimately, 22 studies were included in the meta-analysis for BC (Figure 2), BF was determined in 18 studies as the Phoenix criteria (PSA nadir + 2.0 ng/mL),8 one study used Phoenix criteria or the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition of three consecutive rising PSA measurements,9 one study used Phoenix criteria plus a PSA velocity ≥0.75 ng/mL per year between the nadir and the value before salvage and two studies did not specify the definition of BF.