Cryotherapy As Treatment of Curative Intent for Localized Adenocarcinoma of The Prostate Gland with A Focus on Low-risk and Medium – (Intermediate-) Risk Localized Adenocarcinoma of The Prostate Gland: A Review and Update

Abstract

Cryotherapy which is also referred to as cryosurgery or cryoablation refers to utilization of very cold temperatures to freeze various cells depending upon the pathology. Cryotherapy has tended to be utilized as treatment of curative intent for localized low-risk and intermediate risk carcinomas of the prostate gland. Cryotherapy has also been utilized for the treatment of post-cryotherapy failure prostate cancers with residual tumour or locally recurrent tumour that is confined to the prostate gland. Cryotherapy has also been utilized for the treatment of locally recurrent prostate cancers or localized prostate cancers that have remained following failure of radiotherapy to the prostate cancer of curative intent or radical prostatectomy of prostate for prostate at times. Because cryotherapy of prostate cancer is a minimally invasive treatment procedure, it can be utilized in the treatment of patients who have localized prostate cancer whose tumours could be treated by means of radical prostatectomy or radiotherapy (external beam radiotherapy or brachytherapy) who are considered not to be medically fit to undergo these procedures because of their co-morbidities. The most common treatment options for the management of localized adenocarcinomas of the prostate gland tend to involve radical prostatectomy or radical radiotherapy. Nevertheless, other treatment options for localized prostate cancer that have been undertaken sporadically include: Radiofrequency ablation of the prostate cancer, High intensity focussed ultrasound scan treatment of prostate cancer, irreversible electroporation of prostate cancer. Cryotherapy of prostate cancer as treatment of curative intent has tended to be published sporadically based upon case reports or case series and there has not been reports of an extensive clinical-trials on cryotherapy of localized adenocarcinoma of the prostate. Furthermore, there is no consensus opinion validated definition of biochemical failure pursuant to treatment of localized prostate cancer by cryotherapy. Nevertheless, one article has reported a prospective study with the undertaking of standardized follow-up protocol in which it a series of 108 patients who were diagnosed as having localized adenocarcinoma of prostate that was staged T1c to T2c were treated by primary cryoablation of curative intent and in which the median follow-up was 61 months. With regard to the results of this study, the criteria of biochemical recurrence had been unified based upon the American Society for Therapeutic Radiology and Oncology (ASTRO). The end points of the study included: biochemical progression-free survival (BPFS), cancer-specific survival, as well as overall survival. The complication rates were reported in the study. With regard to the results the biochemical progression-free survival rates were for low-, medium-, and high-risk prostate cancer patients 96.4%, 91.2%, and 62.2%, respectively. The Cancer-specific survival was 98.1%. The overall survival reached 94.4%. The complications that were encountered included incontinence in 5.6% of the patients, urinary tract obstruction in 1.9% of the patients, urethral sloughing in 5.6% of the patients, haematuria in 1.9% of the patients, perineal pain in 11.1% of the patients, and prostatorectal fistula in 0.9% of the patients. Erectile disfunction was found in 98.1% of the patients. The authors concluded that cryotherapy is an effective and minimally invasive treatment for primary carcinomas of the prostate gland in well-selected cases, and the treatment procedure is associated with low surgical risk and good results in terms of biochemical progression-free survival (BPFS), cancer-specific survival, and overall survival. Even though the results of this study had illustrated that the oncology outcome of high-risk prostate cancer was lower than the outcome of low-risk and intermediate-risk prostate cancer more than 60% of patients who had high-risk prostate cancer had biochemical progression-free survival after a median follow-up of 61 months. At the moment cryotherapy is being utilized as treatment of curative option for some low-risk and intermediate (medium) -risk prostate cancer. Cryotherapy of the primary prostate cancer has been utilized for the palliative treatment of some advanced / metastatic prostate cancer which had temporarily ameliorated the general health of few reported patients. In the scenario of persistence of localized low-risk or intermediate- (medium-) risk localized prostate cancer that have persisted following cryotherapy of the prostate cancer, the cancer can be treated by means of either further cryotherapy, radical prostatectomy, radical radiotherapy, HIFU treatment, Irreversible electroporation, and radiofrequency ablation of prostate gland. The complications of erectile / sexual dysfunction, and urinary incontinence / voiding dysfunction following cryotherapy for prostate cancer tends to be more transient in comparison with following radical prostatectomy or radical radiotherapy. It may be that cryotherapy of localized prostate cancer of low-risk, and medium-risk patients may have a slightly inferior long-term oncology outcome in comparison with radical prostatectomy, radical radiotherapy and other minimally invasive treatment options of curative intent but this needs to be further investigated through a large global multicentre treatment comparative study of various treatment options with a long-term follow-up. Nevertheless, cryotherapy of prostate cancer does represent a minimally invasive alternative treatment for localized prostate cancer as treatment of curative intent and it can also be used to treat persistent/locally recurrent prostate cancer following radical radiotherapy and radical prostatectomy. Cryotherapy as treatment option is a safe and effective treatment option for localized low-risk and medium-risk prostate cancer.