The Anatomical and Pathological Characteristics of Irradiated Prostate Cancers May Influence the Oncological Efficacy of Salvage Ablative Therapies

Abstract

Recurrent or radioresistant prostate cancer occurs in approximately 30% of men receiving primary radiotherapy. For men who are candidates for local salvage therapy, the oncological efficacy of ablative therapies may be affected by the anatomical and pathological features of cancers within irradiated prostate glands. We characterized and mapped the prostate cancers in our series of whole mount salvage radical prostatectomy specimens. A total of 47 salvage radical prostatectomies were performed at our institution between 2000 and 2004. Detailed pathological data, including the anatomical distribution of cancers, were obtained from 46 whole mount salvage radical prostatectomy specimens. A total of 70 cancer foci were identified in 46 specimens. Of the specimens 93% had cancer foci at the apex. The median minimum cancer-to-urethra distance was smallest at the apex (4.1 mm) and greatest at the base (13.8 mm). More than 65% of patients had cancer 5 mm or less from the urethra and 7% of patients had cancer directly involving the urethra. Nearly half of all patients had evidence of extraprostatic disease. The anatomical and pathological features in our study demonstrate that a significant portion of irradiated cancers are pathologically advanced and distributed in regions of the prostate (apical and periurethral) which are at risk for undertreatment using current ablative therapies. Our findings raise serious concerns regarding the oncological efficacy of such treatment modalities. Long-term studies without the use of hormonal therapy are needed to determine the oncological efficacy of salvage ablative therapies in patients with radiorecurrent or resistant prostate cancer.