Publications

Abstract

Purpose: In this study our primary aim is the determination of whether systematic template-guided transperineal (TP) biopsies can both accurately locate and sensitively detect tumours in the prostate. The secondary aims are to 1) report on the discrepancies between diagnostic and pathologic Gleason scores and 2) investigate whether prostate size has any effects on the cancer detection rate. Methods: This retrospective diagnostic accuracy study compares the results of primary TP biopsies with the radical prostatectomy (RP) pathology of 414 consecutive patients between November 2002 and August 2010. Results: The average sensitivity and specificity for the detection of tumours in all prostates across all biopsy zones were 48% (95% CI of 42.6 - 53.4) and 84.1% (95% CI of 80 - 88.2), respectively. There was a statistically significant decrease in sensitivity of TP biopsy in larger prostates (t11=4.687, P=0.001). The overall Kappa value was 0.255 (95% CI of 0.212 - 0.298). Grading concordance between biopsy and pathology was achieved in 65.7% of patients. Upgrading of Gleason scores was found in 26.1% of patients and downgrading occurred in 8.5% of patients. Conclusions: Our current TP saturation biopsy method has only demonstrated a fair agreement with the histopathology findings of RP specimens. This is most likely to be due to the small, multifocal nature of prostate tumours in the patient series. Cancer detection rate was found to be lower in larger prostates. Thus, clinicians may consider increasing the number of cores in larger prostates as a strategy to improve cancer detection.