Cryosurgical ablation of the prostate is available at many centers in the United States as a treatment option for localized prostate cancer. Most centers performing cryosurgery quote good short-term success rates, with the majority of patients showing negative post-treatment biopsies and substantial reductions in serum prostate-specific antigen (PSA) levels.<sup>2 Bahn D.K., Lee F., Solomon M.H. , e al. Prostate cancer: US-guided percutaneous cryoablation Radiology 1995 ;  194 : 551

Cliccare qui per andare alla sezione Riferimenti, 3 Bales G.T., Williams M.J., Sinner M. , e al. Short-term outcomes after cryosurgical ablation of the prostate in men with recurrent prostate carcinoma following radiation therapy Urology 1995 ;  46 : 676  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 5 Cohen J.K., Miller R.J., Rooker G.M. , e al. Cryosurgical ablation of the prostate: Two year prostate-specific antigen and biopsy results Urology 1996 ;  47 : 395  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 6 Coogan C.L., McKiel C.F. Percutaneous cryoablation of the prostate: Preliminary results after 95 procedures J Urol 1995 ;  154 : 1813  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 13 Miller R.J., Cohen J.K., Merlotti L.A. Percutaneous transperineal cryosurgical ablation of the prostate for the primary treatment of clinical stage C adenocarcinoma of the prostate Urology 1994 ;  44 : 170  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 14 Onik G.M., Cohen J.K., Reyes G.D. , e al. Transrectal ultrasound-guided percutaneous radical cryosurgical ablation of the prostate Cancer 1993 ;  72 : 1291  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 16 Shinohara K., Connolly J.A., Presti J.C. , e al. Cryosurgical treatment of localized prostate cancer (T1-T4): Preliminary results J Urol 1996 ;  156 : 115  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 18 Wake R.W., Hollabaugh R.S., Bond K.H. Cryosurgical ablation of the prostate for localized adenocarcinoma: A preliminary experience J Urol 1996 ;  155 : 1663  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti, 19 Wieder J., Schmidt J.D., Casola G. , e al. Transrectal ultrasound-guided transperineal cryoablation in the treatment of prostate carcinoma: Preliminary results J Urol 1995 ;  154 : 435  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> Follow-up of cryosurgical patients, however, is still very short, with only a few centers having published PSA or biopsy results at 2 years after the procedure. The durability of cryotherapy, therefore, is unknown, and the pathologic and PSA findings that constitute an appropriate response are not defined fully. Specific questions that need to be addressed include the significance of benign epithelial elements on an otherwise negative postcryosurgery biopsy, the significance of a low but detectable PSA level after treatment, and the durability of the procedure.

After radical prostatectomy the pathologic specimen can be analyzed to determine the bulk and grade of tumor and the presence of extracapsular extension or positive surgical margins. PSA levels should be undetectable in patients considered cured after radical prostatectomy. With radiation therapy, assessment of treatment success is still a matter of debate. PSA levels usually remain detectable and biopsies of the prostate may show residual cancer, even if there is no biochemical or clinical evidence of disease progression.<sup>17 Stamey T.A., Ferrari M.K., Schmid H.P. The value of serial prostate specific antigen determinations 5 years after radiotherapy: Steeply increasing values characterize 80% of patients J Urol 1993 ;  150 : 1856

Cliccare qui per andare alla sezione Riferimenti</sup> Long-term studies of irradiated patients, however, have shown that many patients achieve long-term remission of their cancer despite a low but detectable PSA level. A nadir PSA of less than 1 ng/mL after radiotherapy is associated with a 65% to 85% probability of being disease-free from PSA failure 5 years after radiation.<sup>10 Goad J.R., Chang S.J., Ohori M. , e al. PSA after definitive radiotherapy for clinically localized prostate cancer Urol Clin North Am 1993 ;  20 : 727

Cliccare qui per andare alla sezione Riferimenti, 12 Kavadi V.S., Zagars G.K., Pollack A. Serum prostate-specific antigen after radiation therapy for clinically localized prostate cancer: Prognostic implications Int J Radiat Oncol Biol Phys 1994 ;  30 : 279

Cliccare qui per andare alla sezione Riferimenti</sup> An improvement in the ability to predict long-term cancer control after radiation can be enhanced if a reference range of PSA level less than 0.5 ng/mL is used. Others have argued for the use of reference ranges less than 2 ng/mL to predict control or cure of prostate cancer.<sup>9 Geist R.W. Reference range for prostate-specific antigen levels after external beam radiation therapy for adenocarcinoma of the prostate Urology 1995 ;  45 : 1016  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> As far as assessment of end points is concerned, cryosurgery may be closer to radiation therapy than to radical prostatectomy. As there is no pathologic specimen to examine and the gland has been destroyed in situ rather than removed, reliance is placed on follow-up biopsies of the prostate and serial PSA levels to determine success or failure.