Assessment of prostate biopsy results in patients with and without empirical antibiotic therapy DUE to serum prostate specific antigen elevation

Objectives: To evaluate the impact of antibiotic treatment to total prostate specific antigen (PSA) levels and free/total (f/t) PSA ratio and response of these changes to prostate biopsy results. Materials and Methods: We retrospectively evaluated 1,062 prostate biopsy performed patients with elevated age-adjusted serum PSA levels from 2004 to 2016. Patients treated with 5-alpha-reductase inhibitors and who has abnormalities on digital rectal examination were excluded. A total of 303 patients who met these criteria and had control levels of PSA or before and after biopsy f/t PSA ratio determinations because of PSA levels between 4 and 10 ng/mL were included into this study. There were 214 patients with persistent elevated serum PSA levels after a mean duration of 4 weeks (range; 2-8) of antibiotic treatment followed by prostate biopsy (treatment group) and 89 patients who had prostate biopsy after a mean followup of 1 month without antibiotherapy (control group). The groups were compared with regard to changes in serum PSA levels and f/t PSA ratios with a 5% and 10% cut off values. Results: The mean age of patients were 63 years (range; 45–86). In treatment group (n= 214), no significant difference was detected in serum PSA levels at both cut off values. In control group (n= 89), there was a significant rise in subsequent PSA levels at both cut off values (for 5% cut off value p< 0.001; for 10% cut off value p< 0.001). If we evelaute treatment and control group together (n= 303) for the change of PSA levels, raise and decrease in PSA values were significantly high in treatment group for both cut off values (for %5 cut off value p< 0.001, p< 0.001; for %10 cut off value p= 0.001, p= 0.001). There was no difference between f/t PSA ratio changes and antibiotic treatment or observation for both cut off values. For the treatment and control group particularly and combined together, there was no difference between serum PSA levels and prostate biopsy results in both cut off values. There was a statisctically significant relationship between patients with changed f/t PSA ratio in treatment group and pathology results for both cut off values. According to that, patients with increased f/t PSA ratio had more likely BPH in biopsy results and patients with decreased ratio were cancer as well (for %5 cut off value p= 0.004, p= 0.014; for %10 cut off value p= 0.014, p= 0.026). If we evaluate treatment and control group together, there was no significant difference between f/t PSA ratio changes and biopsy results. Conclusion: We decide to perform prostate biopsy with subsequent PSA levels with or without treatment to the patients with normal digital rectal examinatiorn and elevated age-adjusted serum PSA levels. To decide for prostate biopsy, it is suggested that f/t PSA ratio is more useful than PSA levels in serum especially for the patients treated with antibiotics.