Abstract

Objective: To compare 6- or 12-core first biopsy results in the prostate and to determine the relationship between biopsy core number and percentage of cancer detected.

Materials and methods: Prostate biopsy results of the patients in our clinic were investigated retrospectively for the last five years. Patients with prostate specific antigen (PSA) level of 4-10 ng/mL and first line biopsies were included in the study. Standard biopsy procedure was applied as 6- or 12-cores. Age, PSA level, free PSA ratio, digital rectal examination (DRE) results, prostate volume measured by transrectal ultrasonography, percentage of cancer detected, and their distribution according to Gleason scores were investigated. 

Results: The results of 383 biopsies were evaluated. The mean age was 66 years, prostate volume was 50 cc, PSA level was 6 ng/mL, and free/total PSA ratio was 17%. Although the percentage of cancer detection was higher in 12-core biopsies than 6-core (21.5% vs. 25.3%), this difference was not statistically significant. In multivariate analysis, PSA and DRE findings were identified as factors affecting cancer detection. In patients with prostate volume of 30-60 cc, cancer detection rate was higher in 12-core biopsy group, but similar in other volumes.

Conclusion: In patients with PSA level of 4-10 ng/mL, prostate volume is <30 cc, and DRE findings are positive; 6-core first prostate biopsy is sufficient. When prostate volume is between 30-60 cc, 12-core biopsy is essential, but for prostate volume over 60 cc, the difference between 6- and 12-core is insignificant, thus additional core biopsy is necessary.