5. Whole gland cryosurgical ablation of prostate cancer

Abstract

Introduction and background: Prostate cancer may be a lethal disease causing significant suffering, usually for men of older age. Unfortunately, our understanding is limited when it comes to growth rate and the time when metastases develop. Radical treatment may be effective in properly selected patients, but side effects are significant and contemporary treatment demands big resources. In spite of overtreatment, failure rates are high and there is great need of salvage treatment. Cryosurgical ablation (CSA) is a minimally invasive treatment option which may be offered as day-surgery and is a preferred modality for focal treatment of prostate cancer. The aim of this presentation is to provide an overview of contemporary evidence for CSA as primary and salvage treatment in prostate cancer, and to discuss how the technique of CSA may be improved. Materials and methods: A Medline/Pubmed search using Scopus and Science direct for articles published in the English language was undertaken. The following search terms were used: Prostate cancer, primary treatment, salvage radiation treatment or therapy, salvage brachytherapy, salvage prostatectomy, salvage cryoablation or cryotherapy, salvage HIFU (high intensity focused ultrasound), and permutations of these procedures. Papers were selected for scrutiny based on their pertinence, the study size and overall contribution to the field. Results: Salvage CSA. Primary treatment fails in up to 40% of patients after radical prostatectomy (RP) and up to 67% after external beam radiation (EBRT). 10 year data after salvage CSA show biochemical disease free survival between 40–60%, incontinence rates 3–13%, rectal fistula rate of 1–2% and need of TURP in 3%. Published results depend heavily on patient selection. Unfortunately, most patients with radiation failure are not offered salvage treatment but are given ADT which might increase the risk of cardiovascular events. Primary CSA. 10 year results of primary CSA are similar to EBRT and RP in terms of evidence for progression. A positive biopsy rate of 7.7% at 36 months was found in a RCT of CSA versus EBRT, and a 10 year negative biopsy rate of 77% was found in a prospective case series. The incontinence rate is 0.9% but erectile dysfunction is still high with 64% reported in a recent series. The need for TURP after CSA is about 1% and the risk of rectal fistula is almost negligible. Discussion: CSA may kill prostate cancer in primary and salvage settings. The procedure is technically demanding as there is a delicate balance between freezing hard enough for cell death and not causing damage to surrounding structures. The challenge is to achieve killing conditions in all regions of the prostate. A cryosensitizer which gives killing potential to ice near the freezing point should be aimed at. Vitamin D-3 is an interesting alternative for further studies. The importance of slow thawing also needs further exploration as there seems to be differences in practice between US and European colleagues.