Statement on Salvage Cryosurgical Ablation of the Prostate
from the American Urological Association
Definition: Salvage CSAP is defined as treatment of patients who have failed primary therapy for localized prostate cancer (generally radiotherapy with either external beam or brachytherapy) with probes designed to create sufficiently low temperatures throughout the prostate so as to eliminate recurrent or residual tumor.
Literature Survey: A MEDLINE search using the key words prostatic neoplasm and cryosurgery were used to generate potential abstracts for review. From a print-out of 129 abstracts, a total of 56 were selected for full review, based upon potential primary evidence concerning either efficacy or complications associated with salvage cryotherapy for prostate cancer. Review of the literature found no randomized, controlled trials of CSAP for salvage therapy for prostate cancer. A spreadsheet of 61 columns was then used to extract data for review. When multiple publications from the same institution were noted, the most recent update of a series was used to populate the spreadsheet.
Summary: A total of six series of patients have been published that summarize efficacy, complications, or both for salvage cryosurgical ablation of the prostate (CSAP). In these six series are a total of 285 patients (range in series from 18-150 patients). Some series have been summarized in as many as 8 prior publications. While most series include patients that have failed either external beam radiation or brachytherapy, some have included patients who have failed hormones or chemotherapy alone or in combination with radiation therapy.
Mean patient age ranged from 65.6-69 years. Tumor stage prior to treatment includes primarily patients with clinically localized (T1-2) or regionally advanced (T3-4) disease. Rarely is a patient included who has metastatic disease. The mean interval from radiation and CSAP was reported to be 3.9 and 4.0 years in two series. Neoadjuvant hormonal therapy (a treatment that would be expected to potentially confound evaluation of treatment efficacy) was given in various ranges of patients (from a low of 26% in one series to 100% in another series. The treatment is generally given under ultrasound guidance with some form of urethral warming device but a double-freeze is not universally performed.
The mean followup after CSAP ranged from 12-36 months in four series reporting these data. PSA responses were frequent with two series noting either 60% of patients reaching a nadir value < 0.1 ng/ml or 67% reaching the 'normal range'. A biochemical (PSA) failure rate of 58% was noted in one series while 1% had a stable but detectable PSA with 31% having an undetectable PSA. In the one series reporting PSA biochemical free survivals in a Kaplan-Meier fashion, the biochemical recurrence free survivals at 6 and 12 months were 79% and 66%, respectively.
A second method of measuring treatment efficacy was post-treatment biopsy. Not all patients in not all series underwent biopsy but positive biopsy rates ranged from 14% to 37%.
Complications were common among treated patients with one series reporting that only 11% of patients had no complications. Urinary incontinence rates ranged from 9% to 83% with total incontinence rates reported between 8.7% and 21% and in one series, 4.5% of patients required placement of an artificial urinary sphincter. Urethral sloughing was reported in 15% and 27% of patients. Urinary retention developed in 2.6% and 27% of patients in two series. A transurethral resection of the prostate was required in 4%, 4.5%, and 17% of treated patients in 3 series. A urethral stricture or bladder neck contracture was noted in between 4% and 22% of patients. Moderate to severe perineal or rectal pain was reported in between 8-37% of patients and was noted in 3 series. Urinary tract infections were reported in 1%, 9%, and 39% of treated patients in 3 series. Hematuria was noted in 2-5.5% of patients and a recto-urethral fistula was noted in 1%, 4%, 8.7%, and 11% of patients in four series. Impotence rates were reported in four series: 20%, 72%, 91%, and 100%.
Summary: After reviewing the available peer reviewed literature, there is inadequate data to establish the durable efficacy of cryosurgical ablation for local recurrence of prostate cancer after initial external beam radiation treatment in attempt to cure. In a situation that presents no consistently successful options, cryosurgical ablation of the prostate for patients who fail radiation therapy for carcinoma of the prostate is a treatment option. There is some evidence that there is a PSA response to treatment and many patients will have a negative biopsy but follow-up remains very short in published series. The relative contribution of neoadjuvant or adjuvant hormonal therapy given in many series is unknown. Thus, how CSAP would compare to just hormonal therapy alone is uncertain. Complications seem to occur to some extent in most patients with high rates of incontinence and impotence. More debilitating complications such as recto-urethral fistulas presage other, more significant interventions for their correction.