ProstatespecificantigenPSA is an important serological indicator for the early diagnosis of prostatecancer. In domestic urology clinical care, serum PSA testing is routinely performed in patients diagnosed with benignprostatichyperplasiaBPH, to rule out prostate cancer. Patients with PSA >4.0ng/ml are usually subjected to transrectal ultrasound guided prostate puncture biopsy to obtain a definitive pathological diagnosis.