24th Int'l Prostate Cancer Update: Abstract - Long-term results of focal therapy for prostate cancer

VAIL, CO USA (UroToday.com) - Introduction: The introduction of breast-sparing surgery (i.e., “lumpectomy”) revolutionized the management of breast cancer. The use of lumpectomy showed that quality of life could be optimized without compromising treatment efficacy.

Complications of prostate cancer treatment, including impotence and incontinence, adversely alter the male lifestyle no less than the loss of a breast does for a woman. In 2002, Onik et al. introduced the concept of focal therapy for prostate cancer. The intention was to try to limit prostate cancer treatment morbidity while maintaining good cancer results. Focal therapy is now established as a major trend in prostate cancer management although long-term data on patients who have undergone focal therapy has not been available. In this study we will present follow-up on 70 patients who underwent focal therapy using cryoablation for prostate cancer who have been followed for an average of 10 years.

24th cap updateMaterials and Methods: All patients were staged for cryosurgery using prostate biopsy. Before 12/31/2002 traditional 12-core TRUS biopsy was used with a repeat biopsy on the side opposite the demonstrable cancer After 12/31/2002, transperienal 3D mapping biopsy was used. Cryoablation was carried out in all known areas of cancer, regardless of whether they met the criteria for a significant tumor or not, using standard cryosurgical parameters with two freeze cycles. Based on 3D-PMB all areas of potential extracapsular spred were prophylactically treated. For instance if the 3D-PMB shows cancer next to the neurovascular bundle (NVB) that NVB would be included in the freeze. All patients had the rectum separated from the prostate by a saline injection into Denonvilliers fascia allowing complete freezing without concern for rectal fistula. Temperature monitoring confirmed critical locations in relation to the cancer reached -40 degrees C. Passive thawing was always carried out. Patients with high-grade cancer next to the urethra had a focal TURP to prevent cancer recurrence due to the urethral warmer. Patients were followed with serum PSA every 3 months for the first 2 years than every 6 months after that. Post operative biopsies were carried out on any patient that had evidence of disease progression on PSA. Disease stability was determined by the Phoenix criteria.

Results: A total of 70 patients who underwent focal cryo have at least 8 years follow-up. Follow-up ranges from from 8 years to 18 years with a mean follow-up of 10.1 years. 41 patients were Gleason 6 or less, 24 Gleason 7 (6 patients 4+3, 18 Patients 3+4) and and 5 Gleason 8 or greater. 15 patients had a PSA of 10 or greater. Using the D'Amico criteria 9 patients were high risk, 32 were medium risk and 39 were low risk (exactly the same as Ginsburg indicated that focal can be used on the range of patients.

Overall actuarial survival was 66/70 (94%), Disease specific survival was 64/64(100%). We do however have an additional 59 patients with less than 8 year follow-up, 2 of which died from prostate cancer. If they are added, disease specific survival is 124/126 (98.4%) Overall Biochemical Disease free survival was 62/70 (89%), BDFS for high risk patients was 8/9 (89%), BDFS for medium risk was 28/32 (88%), BDFS for low risk patients was 36/39 (92%). 20/70 (28.5%) patients had bilateral multifocal disease that required bilateral freezing at their first procedure, 19/20 (95%) were BDF. 7/70 (10%) were retreated with cryo to the opposite side of the original procedure 7/7 are BDF. Two patients with local recurrence underwent radiation and both are BDF. One patient underwent a radical prostatectomy and radiation and is now on ADT. In total 10/70 (14%) patients had a local recurrence that needed treatment, 9/10 (90%) remain BDF. All patients were continent with no pads immediately after the first procedure (100%) one patient, converted on a second procedure to a whole-gland freeze, had mild stress incontinence requiring pads while playing golf.

58/70 patients were potent preoperatively. 54/58 (94%) were potent postoperatively with or without the use of oral agents, to their satisfaction, within 6 months after the procedure. However, 11 patients were ultimately rendered impotent by additional treatment -- 7 by additional cryo, 4 by a combination of ADT, radiation, or radical prostatectomy. Interestingly, 4/11 preoperatively impotent patients were potent after the procedure.This was due to the aggressive potency rehab that we provide patients with, immediately after the procedure. 48/60 patients (80%) therefore ultimately either retained their potency or reverted from impotent to potent.

No other complications were noted. Blood loss was virtually zero. No rectal fistulas were seen and no patient needed a further procedure for urinary obstruction.

Conclusions: The long-term results of focal therapy using cryoablation appear to be equivalent or better to other more traditional therapies in all grades of disease. In this series all the risk levels remarkably had the same BDFS. The one common factor in all the risk levels was the same level of local control afforded by the ability to treat extra capsular disease and retreat those with local recurrences. It raises the facsinating possibility that the differences in survival always attributed to the inherent nature of higher grade disease to metastasize may not be true and that it is the difference in our ability to gain local control with high risk disease that may be the reason.

Therefore, limitation of focal therapy to low risk patients is not necessary. Repeat treatment of those patients who have a local recurrence discovered, does not appear to negatively impact patient disease specific or BDF survival. Patients treated with bilateral multifocal disease appear to do as well as unilateral tumors and all grades and PSA levels, appear to have excellent results compared to other treatment modalities. Focal therapy achieves these results with minimal morbidity in terms of incontinence and potency. The safety and long term efficacy of focal cryoablation is now established. Investigators now have the data to have a comfort level to conduct comparative level 1 evidence studies, between focal therapy and robotic RP and the various forms of radiation. These results, if reproduced, will fundamentally change the paradigm of prostate cancer management.

Presented by Gary Onik, MD at the 24th International Prostate Cancer Update - February 19 - 22, 2014 - Cascade Conference Center - Vail, Colorado USA

Medical Director/The Center for Recurrent Prostate Cancer, Aventura, Florida
Adjunct Professor of Mechanical Engineering, Department of Engineering, Carnegie Mellon University


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