Preliminary outcomes following cryosurgical ablation of the prostate in patients with clinically localized prostate carcinoma.
Cryosurgical ablation of the prostate is a novel therapeutic modality that induces cell lysis in the prostate by direct application of low temperatures. We have been conducting an ongoing prospective pilot study of the use of cryosurgical prostate ablation in treating patients with nonmetastatic prostate adenocarcinoma since January 1993. Results in 145 consecutive patients with mean 36 months and minimum 12 months of followup are presented. Accrual was open to patients with clinical stages T1a to T3c prostate adenocarcinoma. Pelvic lymph node dissections were recommended but not required for patients with prostate specific antigen (PSA) greater than 15 ng./ml. before study entry. PSA changes, random prostate biopsy findings and morbidities after cryosurgical prostate ablation were recorded for each patient. Overall actuarial rates at 42 months for maintaining PSA less than 0.3 and less than 1.0 were 59% and 66%, respectively. The overall actuarial progression-free rate at 60 months was 56%. Among 160 biopsies performed 16% showed some evidence of residual carcinoma. Overall crude rates of maintaining either a negative biopsy or PSA less than 0.3 at 6 and 24 months after cryosurgical prostate ablation were 87% and 73%, respectively. Significantly higher morbidities were seen in previously radiated patients undergoing cryosurgical prostate ablation compared to those with no prior radiation. Among nonradiated patients 85% experienced no significant morbidity after cryosurgical prostate ablation. Although preliminary, short-term outcomes after cryosurgical prostate ablation appear to be comparable to identical outcomes reported for external beam radiotherapy. Based on these results cryosurgical prostate ablation appears to be an effective therapeutic alternative for treating patients with localized prostate adenocarcinoma.