Hospitalization decreases serum prostate-specific antigen values compared with outpatient values in patients with benign prostatic diseases

Purpose: To investigate whether hospitalization influences serum prostate-specific antigen (PSA) values. Materials and Methods: Transrectal ultrasound-guided prostate biopsies were performed for detecting prostate cancer in 2,017 patients between February 2001 and April 2011 at Ajou University Hospital. Of those patients, 416 patients who were hospitalized for prostate biopsies, whose serum PSA values were measured at the outpatient department within 1 month of admission and also just after admission, and who had negative prostate biopsy results were included in the present study. We retrospectively reviewed the data of the 416 patients and compared the serum PSA values measured in the outpatient department with those measured during hospitalization. Res ul t s: Among all 416 patients, the interval between the two PSA measurements was 22.2 days (range, 3 to 30 days) and the prostate size measured by transrectal ultra-sonography was 53.63 mL (range, 12.8 to 197.9 mL). Among all patients, mean serum PSA levels measured during hospitalization were significantly lower than those measured in the outpatient department (6.69 ng/mL vs. 8.01 ng/mL, p<0.001). When stratified according to age, the presence or absence of chronic prostatitis in the biopsy pathology, serum PSA levels, and prostate size, the serum PSA levels measured during hospi-talization were significantly lower than those measured in the outpatient department in all subgroups, except in cases aged 20 to 39 years and those with PSA<4 ng/mL, in whom no significant differences were shown. Conclusions: Hospitalization decreases serum PSA values compared with those measured on an outpatient basis in patients with benign prostatic diseases. Therefore, serum PSA values should be checked on an outpatient basis for serial monitoring.