Abstract: PD40-04
Sources of Funding: None.

Introduction

There have recently been a number of reports on predictors for a positive repeat prostate biopsy in patients on an outpatient-referral basis. On PSA prostate prostate cancer screening, unlike outpatient referral basis, a clarification to select screened patients for repeat biopsy needs to be balanced by cost and survival benefit. For this purpose, a validation of the screening system and its modification, if necessary, are extremely important. The aim of this study is to assess possible predictors in determining criteria for repeat biopsy in a prostate cancer screening population.

Methods

A total of 93553 men over 55 years-of-age have participated in a prostate cancer screening program in Otokuni district, Kyoto, Japan for 21 years. Transperineal systematic biopsy with 8-12 cores was carried out in the cases of positive digital rectal examination (DRE) or positive transrectal ultrasonography (TRUS) or a prostate specific antigen (PSA) value greater than 10.0 ng/mL. For those with a PSA level from 4.1 to 10.0ng/mL, and negative DRE and TRUS findings, biopsy was indicated only when PSA density (PSAD) was greater than 0.15. The same indication was applied for the repeat biopsy.

Results

A repeat biopsy after an interval of more than 1 years was carried out in 401 patients and was positive in 167 (41.6%) patients. The PSA value at the diagnosis of cancer declined from the initial value in 26 men (15.6%). The assessment parameters are as follows: age at the final biopsy, change of PSA value, PSA velocity, DRE finding and PSAD value at the latest screening. In multivariate analysis, age, PSAD and positive DRE finding are independent parameter in predicting positive repeat biopsy. The odds ratio in Age>72, PSA>0.30 and positive DRE are 1.86 (1.18 - 2.96), 3.91 (2.47 - 6.24), 2.35(1.09 -5.25), respectively. Of those 3 parameters, when repeat biopsy definition is determined in either positive of 3 parameters, unnecessary biopsy can be decreased in 17.0 %, while localized cancer with low risk group will be missed in 10.1%.

Conclusions

A decrease in the repeated PSA value cannot predict a negative biopsy outcome under the consecutive and established biopsy criteria. The combination of these three parameters (age, positive DRE and PSAD) might help to reduce unnecessary repeat biopsies in the high-risk cohort of patients with negative initial biopsies._x000D_ _x000D_

Funding

None.