Unilateral PCa Difficult to Predict
Biopsy findings of unilateral prostate cancer are unreliable for identifying candidates for hemi-ablative focal therapy, according to researchers.
Basir Tareen, MD, and colleagues at New York University School of Medicine in New York City studied 1,458 men who underwent radical prostatectomy (RP) for prostate cancer. Of 590 patients whose biopsy results indicated unilateral disease, only 163 (27.3%) actually had unilateral disease on examination of their RP specimen, the investigators reported in BJU International (2009; published online ahead of print).
Even among men whose biopsy findings indicated low-risk, unilateral tumors, only 28.4% had unilateral disease based on their RP specimen. The clinical characteristics of low-risk tumors included clinical stage T1c, a Gleason score less than 7, and a PSA level below 10 ng/mL.
Pathologic features such as PSA level, Gleason score, number of positive cores, percentage of cores positive, prostate volume, and high-grade prostatic intraepithelial neoplasia did not improve prediction of unilateral disease.
Moreover, Dr. Tareen's group found that taking more biopsy cores did not increase the predictive accuracy for focality. Even among patients who had 16 or more cores obtained, the positive predictive value was only 31.5%.
Focal therapy has emerged in recent years as a potentially attractive option for curing prostate cancer while minimizing the impact of treatment-related adverse effects, the investigators noted. Various modalities have been proposed, such as high-intensity focused ultrasound, radiofrequency ablation, and cryotherapy.
“The true challenge lies in appropriately identifying patients who would be ideal candidates for such treatments,” the authors observed.