Histological changes in prostate biopsies after salvage cryotherapy: effect of chronology and the method of biopsy.

OBJECTIVES: To examine changes in prostate biopsies at different intervals after salvage cryotherapy and the effect of biopsy type (transrectal ultrasonography-guided vs transurethral resection, TUR), as the sequence and extent of histological changes occurring in the prostate after salvage cryotherapy for local failure of prostate cancer treatment are unknown.

PATIENTS AND METHODS: In all, 158 prostate biopsies from 150 patients were examined histologically after salvage cryotherapy for prostate cancer after radiotherapy had failed. Specimens were grouped by time from cryotherapy and biopsy technique.

RESULTS: Biopsies showed hyalinization, necrosis, inflammation and residual cancer. Hyalinization became predominant over time, most notably in biopsies with no residual cancer. Core biopsies showed more hyalinization and regenerating glands, while TUR biopsies showed more necrosis and inflammation.

CONCLUSIONS: Tissue cryo-injury and reactive changes last for >1 year; more extensive cryo-injury suggests more effective cancer ablation. A long-term follow-up is necessary, as prostate cancer might remain indolent for >1 year.