Repeat prostate-specific antigen (PSA) test before prostate biopsy: a 20% decrease in PSA values is associated with a reduced risk of cancer and particularly of high-grade cancer

ObjectivesTo analyse the impact of repeating a prostate-specific antigen (PSA) level assessment on prostate biopsy decision in a cohort of men undergoing prostate biopsy. Patients and MethodsFrom 2015 onwards, we consecutively enrolled, at a single institution in Italy, men undergoing 12-core transrectal ultrasonography-guided prostate needle biopsy. Indication for prostate biopsy was a PSA level of 4 ng/mL. Demographic, clinical, and histopathological data were collected. The PSA level was tested at enrolment (PSA(1)) and 4 weeks later on the day before biopsy (PSA(2)). Variations in PSA level were defined as: stable PSA(2) within a 10% variation, stable PSA(2) within a 20% variation, PSA(2) decreased by 10%, PSA(2) decreased by 20%, PSA(2) increased by 10%, PSA(2) increased by 20%, and PSA(2) <4 ng/mL. Percentages and multinomial logistic regression were used to analyse biopsy outcomes. High-grade cancer was defined as Grade group 3. ResultsOverall, 331 patients were enrolled. Prostate cancer was diagnosed in 153/331 (46%) patients and of them 80/153 (52%) had high-grade disease. When compared to the rest of the population, patients with a stable PSA within 20% variation had a higher risk of prostate cancer (odds ratio [OR] 1.80, P < 0.05) and high grade disease (OR 2.56, P < 0.05), patients with a PSA2 decreased by 20% had a lower risk of prostate cancer (OR 0.37, P < 0.05) and high grade disease (OR 0.13, P < 0.05), whilst patients with a PSA2 increased by 10% had an increased risk of high-grade prostate cancer (OR 1.93, P < 0.05). When PSA returned to normal values (<4 ng/mL) both risks of prostate cancer and high-grade disease were reduced (OR 0.33 and 0.01, respectively, P = 0.001). ConclusionIn a cohort of Italian men undergoing prostate biopsy, a reduction of 20% in PSA levels significantly reduced the risk of high-grade prostate cancer. Further multicentre studies should validate our present results.