Can contemporary transrectal prostate biopsy accurately select candidates for hemi-ablative focal therapy of prostate cancer?

OBJECTIVE

To determine if biopsy characteristics can be used to identify men with unilateral prostate cancer on radical prostatectomy (RP) pathological specimens, thereby selecting candidates for hemi-ablative focal therapy.

PATIENTS AND METHODS

Of 1458 men who had RP from January 2000 to June 2007, we identified 590 of 880 evaluable patients with unilateral disease on their preoperative biopsy. Charts were reviewed to record preoperative prostate-specific antigen (PSA) level, high-grade prostatic intraepithelial neoplasia (HGPIN), clinical stage, Gleason score, perineural invasion (PNI), prostate volume, number of positive cores, and percentage of positive cores. Final surgical pathology was evaluated for unilateral cancer. Univariate analysis was used (logistic regression method) to identify independent predictors of unilateral disease on the RP specimen. A subset analysis was done in men with low-risk disease, defined as clinical stage T1C, Gleason score <7 and a PSA level of <10 ng/mL.

RESULTS

Of 590 men with unilateral disease on biopsy, 163 (27.3%) had unilateral disease on the RP specimen. Pathological features, including HGPIN (P = 0.714), Gleason score (P > 0.608), PNI (P = 0.714), number of positive cores (P = 0.076), percentage of cores positive (P = 0.056), prostate volume (P = 0.285), and PSA level (P = 0.062) did not improve the prediction of unilateral disease. When men with unilateral cancer were further stratified to include only those with low-risk disease, 28.4% had unilateral disease on the RP specimen. None of the biopsy or clinical features evaluated were predictors of unilateral disease on the RP specimen.

CONCLUSION

Unilateral prostate cancer on biopsy predicts unilateral disease on RP pathology in only 27.6% of cases. The predictive ability is not improved by adding biopsy and clinical characteristics. Additional methods are needed to accurately identify men appropriate for focal therapy.