Correlation between prostate needle biopsies and radical prostatectomy specimens: can we predict pathological outcome?

Aims: Prostate needle biopsy findings provide important information when considering treatment options. We examine the correlation between needle biopsy and radical prostatectomy pathology to predict patients at high risk of harbouring adverse pathological findings. Methods: We reviewed data from 100 consecutive patients who underwent radical prostatectomy between 1 January 2003 and 31 January 2005 at the Singapore General Hospital. Pre-operative clinical findings and needle biopsy pathological data were prospectively collected and compared with the final histology. Results:The mean pre-biopsy PSA level was 9.4 +/- 5.1 mu g/L. Median maximum percent of tumour in any core was 50% (range 5-100) and mean percentage of positive cores was 34.5 +/- 23%. There was under-grading of the final tumour score in 27 (27%) patients on biopsy as compared with the radical prostatectomy, while over-grading occurred in eight (8%) patients. On stratifying patients pre-operatively into low risk and high risk groups, patients in the high risk group had a significantly higher chance of having adverse radical prostatectomy histology such as extraprostatic extension, positive surgical margins or tumour volume > 3.0 mL (p = 0.041, OR = 3.96, 95%CI 1.13-13.86). Conclusions: Our results demonstrated good pathological correlation between prostate needle biopsies and their radical prostatectomies. Patients with Gleason scores of 7 or more, maximum percent of tumour in any core > 50%, or percent of positive cores of > 50% on needle biopsy had a higher risk of having adverse pathological findings at radical prostatectomy. The converse, however, is not necessarily true, as a result of sampling error during the biopsy.