Oncological effects and complications of salvage cryotherapy for radio-recurrent prostate cancer: a systematic review and meta-analysis

Background

Cryotherapy plays a crucial role in managing radio-recurrent prostate cancer (PCa) after initial treatment. This study aims to provide a comprehensive review of its effectiveness and associated complications.

Methods

A systematic review was conducted using PubMed and EMBASE databases up to June 2024, focusing on recurrence-free survival (RFS) with salvage cryotherapy across various subgroups. Severe complications were also assessed. Survival curves were reconstructed using WebPlotDigitizer and a newly developed Shiny application. The incidence of complications was summarized with a 95% confidence interval (CI) using a random-effects model. Complications were evaluated using the Clavien-Dindo Scale (CDS).

Results

Thirty-six studies were included, with 15 papers (3174 patients) contributing to survival curve reconstruction. Among 1593 patients treated with salvage cryotherapy, the median RFS was 56.7 months, with 2-, 3-, and 5-year rates of 67.6%, 59.5%, and 47.3%, respectively. Factors associated with better RFS included a longer time from primary treatment to salvage therapy (TRS) [> 70 months vs. < 70 months, hazard ratio (HR) (95% CI):0.75(0.58-0.97), p=0.031], lower pre-salvage prostate-specific antigen (PSA) levels [< 5 ng/mL vs. > 5 ng/mL, HR (95% CI):0.78 (0.65-0.93), p=0.005], salvage whole-gland cryotherapy (SWC) [whole vs. focal, HR (95% CI):0.45 (0.37-0.56), p < 0.001], neoadjuvant androgen deprivation therapy (ADT) [Yes vs. No, HR (95% CI):0.79 (0.69-0.89), p < 0.001], and higher adjuvant ADT usage [16.5-34.2% vs. 0-10.5%, HR (95% CI):0.47(0.39-0.56), p < 0.001]. Concerning severe complications, 78 out of 876 patients (8.9%, 95% CI: 7-11) experienced genitourinary (GU) events, 53 out of 633 patients (8.5%, 95% CI: 6-11) suffered from urinary incontinence, 15 out of 493 patients (3.0%, 95% CI: 2-5) had urethral sloughing/stenosis, and 6 out of 522 patients (1.1%, 95% CI: 0-2) developed recto-urethral/vesical fistula. No cases of severe haematuria, urinary tract infection, or urinary retention were reported.

Conclusions

Cryotherapy demonstrates a favorable safety profile and significant RFS benefits for salvage treatment of radio-recurrent PCa. Longer TRS, lower pre-salvage PSA, SWC, and peri-salvage ADT usage appear to be promising prognostic factors for RFS. However, confirmation of these findings requires randomized controlled trials (RCTs) due to the low evidence levels and study heterogeneity.

High-Intensity Focused Ultrasound Ablation for Primary or Salvage Prostate Cancer Therapy: Initial Outcomes in the Veteran Healthcare Setting

High-Intensity Focused Ultrasound (HIFU) provides comparable oncologic, erectile, and urinary outcomes to standard-of-care options for localized prostate cancer. This study reports the largest United States series of HIFU in veterans for both primary and salvage therapies. We retrospectively analyzed the outcomes of 43 veterans treated at the Michael E. DeBakey Veterans Affairs Medical Center from 2018 to 2022. Primary endpoints included prostate-specific antigen (PSA) reduction and local recurrence rates. Secondary endpoints included 30-day complications, Sexual Health Inventory for Men (SHIM), and American Urological Association Symptom Score (AUASS). In our study, 31 veterans (72.1%) received primary treatment and 12 (27.9%) received salvage therapy, with a median follow-up of 23 and 25 months, respectively. Median PSA nadir was 0.16 for primary and 0.12 for salvage groups, with PSA reduction stable over 30 months. Local recurrence occurred in 16.1% of primary and 16.6% of salvage patients. SHIM scores and AUASS were not statistically different before and after HIFU therapy. Short- and intermediate-term results suggest HIFU is a safe and effective treatment option with excellent potency and preserved urinary function, as well as adequate oncological control for primary and salvage therapies for localized prostate cancer in veterans.

Advances in irreversible electroporation for prostate cancer

Irreversible electroporation is a nonthermal ablation technique that uses a high-voltage electric current to create nanosized pores in the cell membrane of a malignant tumor, thus resulting in cell death. In recent years, an increasing number of clinical studies have shown that irreversible electroporation is a safe and effective treatment for prostate cancer. We describe the progress of irreversible electroporation in prostate cancer in recent years in terms of its mechanism of action, clinical studies, advantages and disadvantages and summarize the gaps in existing studies and directions for future research.

The Role of Whole-Gland and Focal Cryotherapy in Recurrent Prostate Cancer

Prostate cancer is the most common non-cutaneous malignancy in men, with the majority of newly diagnosed patients eligible for active surveillance. Despite definitive treatment, a considerable percentage of men will experience biochemical recurrence and even regional and distant metastatic recurrence after radiation therapy or radical prostatectomy. Salvage prostatectomy, while oncologically effective, poses significant morbidity with poor functional outcomes. Salvage cryotherapy has emerged as a promising alternative for localized recurrence, demonstrating safety and efficacy. This review examines the oncologic and functional outcomes of whole-gland and focal salvage cryotherapy, including disease-free survival, cancer-specific survival, and overall survival. The crucial role of multiparametric prostate MRI and evolving role of next-generation PSMA-targeted PET imaging are also examined. The comparison of outcomes of cryotherapy to other salvage ablation modalities, such as high-intensity focused ultrasound (HIFU), is also explored.

Long-term oncologic outcomes of low dose-rate brachytherapy compared to hypofractionated external beam radiotherapy for intermediate -risk prostate cancer

PURPOSE

To compare the long-term oncologic outcomes of intermediate risk (IR) prostate cancer (PCa) patients treated with low dose-rate brachytherapy (LDR-BT) or moderate hypofractionated external beam radiotherapy (HF-EBRT).

METHODS AND MATERIALS

Patients diagnosed with IR PCa and treated with LDR-BT or HF-EBRT between January 2005 and December 2013 were included. Brachytherapy treatment involved a transperineal implant of iodine-125 to a dose of 145 Gy to the PTV, while HF-EBRT was delivered using intensity modulated radiotherapy with 60 Gy in 20 fractions. The Phoenix ''nadir +2'' threshold was used to define biochemical relapse (BR). The cumulative incidence function (CIF) of BR and metastases was reported for each group and compared using the Gray's test to account for the competing risk of death. The Kaplan-Meier (KM) method was used to estimate overall survival (OS) and prostate cancer specific survival (PCSS). Univariate (UVA) and multivariable (MVA) analysis of the CIF of BR and metastases were performed. A 2-tailed p-value ≤ 0.05 was considered statistically significant.

RESULTS

Overall, 122 and 124 patients were treated with LDR-BT and HF-EBRT respectively. Median follow-up was 95 months [interquartile range (IQR): 79-118] in the LDR-BT group and 96 months (IQR: 63-123) in the HF-EBRT group. BR was observed in 5 patients treated with LDR-BT and 34 treated with HF-EBRT. At 60 and 90 months, the CIF of BR was 0.9% and 3.5% in the LDR-BT group vs. 16.6% and 23.7% in the HF-EBRT (p < 0.001). The CIF of metastases at 90 and 108 months, was 0% and 1.6% vs. 3.4% and 9.1% in the LDR-BT and HF-EBRT groups (p = 0.003), respectively. At the last follow-up, 3 patients treated with HF-EBRT died from their cancer [PCSS of 97.5% at 8 years and none died in the LDR-BT group (p = 0.09). On UVA and MVA risk group and treatment modality were independently associated with CIF of BR. On UVA HF-EBRT and ISUP grade group 3 were associated with metastases.

CONCLUSION

LDR-BT was associated with higher biochemical and metastases control in our cohort when compared to moderately HF-EBRT. In the absence of a randomized trial, LDR-BT when feasible should be offered to patients with a life expectancy of >8 years.

Does adding local salvage ablation therapy provide survival advantage for patients with locally recurrent prostate cancer following radiotherapy? Whole gland salvage ablation post-radiation failure in prostate cancer

INTRODUCTION

Some men who experience prostate cancer recurrence post-radiotherapy may be candidates for local salvage therapy, avoiding and delaying systemic treatments. Our aim was to assess the impact of clinical outcomes of adding salvage local treatment in prostate cancer patients who have failed radiation therapy.

METHODS

Following radiation biochemical failure, salvage transperineal cryotherapy (sCT, n=186), transrectal high intensity focused ultrasound ablation (sHIFU, n=113), or no salvage treatment (NST, identified from the pan-Canadian Prostate Cancer Risk Stratification [ProCaRS] database, n=982) were compared with propensity-score matching. Primary endpoints were cancer-specific survival (CSS) and overall survival (OS).

RESULTS

Median followup was 11.6, 25.1, and 14.3 years following NST, sCT, and sHIFU, respectively. Two propensity score-matched analyses were performed: 1) 196 NST vs. 98 sCT; and 2) 177 NST vs. 59 sHIFU. In the first comparison, there were 78 deaths and 49 prostate cancer deaths for NST vs. 80 deaths and 24 prostate cancer deaths for sCT. There were significant benefits in CSS (p<0.001) and OS (p<0.001) favoring sCT. In the second comparison, there were 52 deaths (31 from prostate cancer) for NST vs. 18 deaths (nine from prostate cancer) for sHIFU. There were no significant differences in CSS or OS possibility attributed to reduced sample size and shorter followup of sHIFU cohort.

CONCLUSIONS

In select men with recurrent prostate cancer post-radiation, further local treatment may lead to benefits in CSS. These hypothesis-generating findings should ideally be validated in a prospective clinical trial setting.

Transperineal cryotherapy for unresectable muscle invasive bladder cancer: preliminary experience with 7 male patients

BACKGROUND

Radical cystectomy (RC) with pelvic lymph node dissection (PLND) and urinary diversion (UD) is considered the standard treatment for muscle invasive bladder cancer (MIBC). In a part of patients, RC procedure is aborted due to unresectable disease, other followed treatment like systemic chemotherapy, radiotherapy or cryotherapy may be a better option. The aim of present study was to report the preliminary results of transperineal cryotherapy for unresectable muscle invasive bladder cancer.

METHODS

From January 2011 to August 2013, 7 male patients with pT4b unresectable bladder cancer underwent bilateral ureterocutaneostomy. Two performed a pelvic lymph node dissection (PLND). Then primary transperineal cryosurgery for preserved bladder at the guidance of transrectal ultrasound (TRUS) was performed. All patients underwent a dual freeze-thaw cycle using third-generation cryotechnology with ultrathin 17-gauge cryoneedles. Computer tomography (CT) and/or magnetic resonance image (MRI)were performed at 3 month intervals after cryosurgery to determine whether progression or recurrence occurred.

RESULTS

All cryosurgery was performed successfully, mean operation time was 76.43 ± 25.12 min (range 50-120 min), mean blood loss was 19.29 ± 15.92 ml (range 5-50 ml). Mean hospital stay was 3.86 ± 1.68 day (range 2-7 days). No operative related deaths occurred. Four patients dead due to the metastasis disease at the follow up time of 8, 15, 18 and 37 months, respectively. Six patients received postoperative therapy, of whom 5 patients were treated with combined chemoradiation, and the other one received chemotherapy alone. The progression free survival (PFS) of the 7 patients was 22.00 ± 14.61 months (range 3-40 months). The one, two and three year overall survival (OS) was 85.7%, 57.1% and 42.9%, respectively.

CONCLUSION

Our results suggest that cryosurgery combination with chemoradiotherapy provide a safe and effective alternative method for unresectable pT4b bladder cancer. Longer follow-up is necessary to determine the sustained efficacy.

Long-Term Oncologic Outcomes of Salvage Cryoablation for Radio-Recurrent Prostate Cancer

PURPOSE

Management of localized radio-recurrent prostate cancer is not standardized, partly due to the absence of long-term data on oncologic control and the toxicity of various treatment modalities. We analyzed the long-term oncologic outcomes and morbidity of salvage cryoablation for radio-recurrent prostate cancer.

MATERIALS AND METHODS

Patients undergoing salvage cryoablation for biopsy proven, localized radio-recurrent prostate cancer from 1995 to 2004 were prospectively accrued. Preoperative characteristics, perioperative morbidity and postoperative data were reviewed from a prospectively maintained database or via telephonic contact with the patient. The primary outcome was overall survival. Secondary outcomes were metastasis-free and biochemical disease-free survival. The Kaplan-Meier method was used for survival analysis and multivariable Cox regression analysis was performed.

RESULTS

Of 187 patients 157 (84%) had records available for followup. Mean ± SD age was 69.4 ± 5.8 years and mean presalvage prostate specific antigen was 6.6 ± 5.7 ng/ml. Median followup was 117 months (IQR 55-154). Five and 10-year overall survival was 93% and 76%, respectively. Biochemical disease-free survival at 10 and 15 years was 35% and 22.6% whereas metastasis-free survival at 10 and 15 years was 86% and 71%, respectively. On multivariable analysis precryoablation and nadir prostate specific antigen values were significant predictors of metastasis-free and biochemical disease-free survival. Age at salvage cryoablation (p = 0.008) and nadir prostate specific antigen (p = 0.015) were significant predictors of overall survival. There were 157 Clavien-Dindo grade 1-2 and 22 grade 3 complications.

CONCLUSIONS

A single center, long-term experience documented by a prospectively maintained database shows that cryoablation is a viable salvage option for radio-recurrent prostate cancer as it provides durable biochemical disease-free survival with acceptable morbidity.

Advances of high intensity focused ultrasound (HIFU) for pancreatic cancer

High intensity focused ultrasound (HIFU) is a novel therapeutic modality. Several preclinical and clinical studies have investigated the safety and efficacy of HIFU for treating solid tumours, including pancreatic cancer. Preliminary studies suggest that HIFU may be useful for the palliative therapy of cancer-related pain in patients with unresectable pancreatic cancer. This review provides a brief overview of HIFU, describes current clinical applications of HIFU for pancreatic cancer, and discusses future applications and challenges.