Most men currently diagnosed with localized prostate cancer are likely to have the disease eradicated by one of the available treatment modalities, but the focus on health-related quality of life associated with treatment has intensified. In 2007, the American Urological Association (AUA) released guidelines for the management of clinically localized prostate cancer. This guideline, however, did not address the role of cryosurgery for treatment of the disease because of insufficient long-term efficacy data on metastasis-free, prostate-cancer specific or overall survival. In the November 2008 Journal of Urology, the AUA released a new best practice statement on cryosurgery for the treatment of localized prostate cancer. “This is the first time the AUA has released official guidance on this treatment modality,” says Richard J. Babaian, MD, who chaired the panel that published the statement.
According to the AUA guidelines, several investigations have reported the efficacy and morbidity of cryosurgery for the disease. “Prostate cryosurgery has been found to result in acceptable outcomes with regard to health-related quality of life,” says Dr. Babaian. “It has been associated with reduced costs when compared with other local therapeutic options.” Studies have also shown that short-term PSA relapse-free survival outcomes following cryoablation of the entire prostate are comparable to that of radiation therapy in men with intermediate- and high-risk disease.
According to the AUA best practice statement, cryosurgery can be used as primary therapy or salvage therapy (Table 1). The minimally invasive treatment involves freezing cancerous tissue. As a result of this process, tumors are destroyed. Therma probes are placed into the prostate, where a controlled freezing-thawing process ensues. Clinicians must monitor patients closely and pay special attention to temperature, freeze cycles, and thaw rates. Although cryosurgery is often performed in outpatient settings, research has indicated that some patients may require an overnight hospital stay. The average operative time associated with the procedure is about 2 hours.
Cryosurgery, according to the AUA panel, is an option when appropriate patients do not want or are not good candidates for radical prostatectomy because of certain comorbidities. Dr. Babaian says that cryotherapy as a first treatment may be a viable option for men with clinically localized prostate cancer of any grade with no metastasis. “High-risk patients may require multimodal therapy,” he adds. “In some larger glands, neoadjuvant cytoreduction can be considered to overcome technical limitations in treatment. It should be noted, however, that neoadjuvant or concomitant hormonal therapy has not been shown to positively impact subsequent cryosurgery outcomes.”
Radiation patients with biochemical recurrence and a PSA of less than 10 ng/ml could be considered candidates for salvage cryotherapy. It is secondary treatment for patients without evidence of metastasis and whose local recurrence is detected early. Several major variables, especially PSA doubling time, must be considered prior to using cryotherapy as a salvage therapy. “Salvage cryotherapy should only be used in patients with a positive prostate biopsy,” says Dr. Babaian. “Radiation therapy reduces the size of the prostate, so gland volume is not as much a limiting factor as it is when cryotherapy is used as a primary treatment.”
There are several complications of cryosurgery that should be considered when making decisions about utilizing the procedure. In addition to incontinence and erectile dysfunction, complications include urinary retention, swelling, and fistula formation. Although a concern, the rates of these complications have been less than 10% in current investigations. “To optimize results, it’s important that clinicians have a keen ability and awareness of how to appropriately use ultrasound,” Dr. Babaian says. “Success of the procedure depends on it. It’s also paramount to closely monitor tissue freeze rates, temperatures, thaw rates, and freeze cycles [Table 2]. The good news is the mortality rate associated with cryosurgery for localized prostate cancer is very low.”
The AUA best practice statement on cryosurgery provides clinicians with a current understanding of the principles and strategies for performing cryosurgery in localized prostate cancer. It is based on reviews of medical literature, clinical experience, and expert opinion. “Unlike a clinical guideline,” Dr. Babaian explains, “best practice statements do not use formal meta-analyses of the literature. However, the hope is the document will provide more helpful information on this emerging prostate cancer treatment option. Decisions to use one treatment over others should be made by physicians and patients collaboratively after all other available options and potential complications are exhaustively reviewed. Cryosurgery will continue to be explored, and there is further evidence that more minimally invasive options will continue to be developed in the coming years.”
Readings & Resources (click to view)
Babaian RJ, Donnelly B, Bahn D, et al. Best practice statement on cryosurgery for the treatment of localized prostate cancer. J Urol. 2008;180:1993-2004. Available at: http://download.journals.elsevierhealth.com/pdfs/journals/0022-5347/PIIS002253470802017X.pdf.
Thompson I, Thrasher JB, Aus G, Burnett AL, Canby-Hagino ED, Cookson MS, et al. Guideline for the management of clinically localized prostate cancer: 2007 update. J Urol. 2007;177:2106-2131.
Gage AA, Baust JG: Cryosurgery of tumors. J Am Coll Surg. 2007;205:342-356.
Prepelica KL, Okeke Z, Murphy A, Katz AE. Cryosurgical ablation of the prostate: high risk patient outcomes. Cancer. 2005;103:1625-1630.
Ellis DS, Manny TB Jr, Rewcastle JC. Cryoablation as a primary treatment for localized prostate cancer followed by penile rehabilitation. Urology. 2007;69:306-310.
Mouraviev V, Polascik TJ: Update on cryotherapy for prostate cancer in 2006. Curr Opin Urol. 2006;16:152-156.