Predictors of biochemical recurrence after primary focal cryosurgery (hemiablation) for localized prostate cancer: A multi-institutional analytic comparison of Phoenix and Stuttgart criteria

mpMRI-US Fusion-Guided Targeted Cryotherapy in Patients with Primary Localized Prostate Cancer: A Prospective Analysis of Oncological and Functional Outcomes

Simple Summary

Targeted cryotherapy is an emerging treatment for prostate cancer (PCa). mpMRI is a powerful tool for image fusion techniques that deliver incremental precision in diagnostic and treatment of PCa. Fusion targeted cryotherapy (FTC) arises from the simultaneous application of both these procedures. Recurrence is a concern after any type of PCa treatment, especially after targeted treatments. In this article we investigate the recurrence rate after FTC and the role of Prostate-Specific Antigen (PSA) as a predictor of recurrences. Our research provides new evidence on the feasibility of FCT by providing new insights on patient management.

Abstract

Targeted therapy (TT) for prostate cancer (PCa) aims to ablate the malignant lesion with an adequate margin of safety in order to obtain similar oncological outcomes, but with less toxicity than radical treatments. The main aim of this study was to evaluate the recurrence rate (RR) in patients with primary localized PCa undergoing mpMRI/US fusion targeted cryotherapy (FTC). A secondary objective was to evaluate prostate-specific antigen (PSA) as a predictor of recurrences. We designed a prospective single-center single-cohort study. Patients with primary localized PCa, mono or multifocal lesions, PSA ≤ 15 ng/mL, and a Gleason score (GS) ≤ 4 + 3 undergoing FTC were enrolled. RR was chosen as the primary outcome. Recurrence was defined as the presence of clinically significant prostate cancer in the treated areas. PSA values measured at different times were tested as predictors of recurrence. Continuous variables were assessed with the Bayesian t-test and categorical assessments with the chix-squared test. Univariate and logistic regression assessment were used for predictions. A total of 75 cases were included in the study. Ten subjects developed a recurrence (RR: 15.2%), while fifty-six (84.8%) patients showed a recurrence-free status. A %PSA drop of 31.5% during the first 12 months after treatment predicted a recurrence with a sensitivity of 53.8% and a specificity of 79.2%. A PSA drop of 55.3% 12 months after treatment predicted a recurrence with a sensitivity of 91.7% and a specificity of 51.9%. FTC for primary localized PCa seems to be associated with a low but not negligible percentage of recurrences. Serum PSA levels may have a role indicating RR.

High-Intensity Focused-Ultrasound Focal Therapy Versus Laparoscopic Radical Prostatectomy: A Comparison of Oncological and Functional Outcomes in Low- and Intermediate-Risk Prostate Cancer Patients

To compare oncological and functional outcomes of high-intensity focused-ultrasound (HIFU) focal therapy (FT) versus laparoscopic radical prostatectomy (LRP) in patients treated for low- or intermediate-risk prostate cancer (PCa), we retrospectively analyzed data of consecutive patients comprising 30 men, who underwent HIFU-FT, and 96 men who underwent LRP, in an academic center. Oncological outcomes were assessed based on the follow-up prostate-specific antigen values. We used the International Index of Erectile Function short form score to assess erectile function (EF). Urinary continence status was defined based on the number of pads used per day. Median follow-up was 12.5 and 19.1 months in the LRP and HIFU-FT groups, respectively. The effects were computed after propensity score matching and expressed as average treatment effect (ATE). Compared to LRP, HIFU-FT was associated with increased risk of treatment failure (ATE 0.103–0.164, depending on definition, p < 0.01) and lower risk of urinary incontinence (ATE −0.808 at 12 months, p < 0.01). Risk of erectile dysfunction was higher in the LRP group (ATE 5.092, p < 0.01). Our results demonstrate that HIFU-FT may be a reasonable treatment option in selected PCa patients, willing to preserve their EF and urinary continence yet accepting a higher risk of treatment failure.

An Updated Systematic Review on Focal Therapy in Localized Prostate Cancer: What Has Changed over the Past 5 Years?

CONTEXT

Focal therapy is a promising, minimally invasive strategy to selectively treat localized prostate cancer. A previous systematic review indicated that there is growing evidence for favorable functional outcomes, but that oncological effectiveness was yet to be defined.

OBJECTIVE

To assess the effectiveness of focal therapy in patients with localized prostate cancer in terms of functional and oncological outcomes.

EVIDENCE ACQUISITION

PubMed, Embase, and The Cochrane Library were searched for studies between October 2015 and December 31, 2020. In addition, the research stages were acquired according to the Idea, Development, Exploration, Assessment, Long-term study (IDEAL) recommendations. Ongoing studies were identified through clinical trial registries.

EVIDENCE SYNTHESIS

Seventy-two studies were identified exploring eight different sources of energy to deliver focal therapy in 5827 patients. Twenty-seven studies reported on high-intensity focused ultrasound (HIFU), nine studies on irreversible electroporation, 11 on cryoablation, eight on focal laser ablation and focal brachytherapy, seven on photodynamic therapy (PDT), two on radiofrequency ablation, and one on prostatic artery embolization. The majority of studies were prospective development stage 2a studies (n = 35). PDT and HIFU, both in stage 3, showed promising results. Overall, HIFU studies reported a median of 95% pad-free patients and a median of 85% patients with no clinically significant cancer (CSC) in the treated area. For PDT, no changes in continence were reported and a median of 90% of patients were without CSC. Both treatments were well tolerated.

CONCLUSIONS

Over the past 5 yr, focal therapy has been studied for eight different energy sources, mostly in single-arm stage 2 studies. Although a first randomized controlled trial in focal therapy has been performed, more high-quality evaluations are needed, preferably via multicenter randomized controlled trials with long-term follow-up and predefined assessment of oncological and functional outcomes and health-related quality-of-life measures.

PATIENT SUMMARY

Focal treatment (FT) of prostate cancer has potential, considering that it has less impact on continence and potency than radical treatment. Our systematic review indicates that despite the method being studied extensively over the past half decade, the majority of studies remain in an early research stage. The techniques high-intensity focused ultrasound and photodynamic therapy have shown most progression toward advanced research stages and show favorable results. However, more high-quality evidence is required before FT can become available as a standard treatment.

Cryoablation, high-intensity focused ultrasound, irreversible electroporation, and vascular-targeted photodynamic therapy for prostate cancer: a systemic review and meta-analysis

Cryoablation (CA), high-intensity focused ultrasound (HIFU), irreversible electroporation (IRE), and vascular-targeted photodynamic therapy (VTP) have been evaluated as novel strategies for selected patients with prostate cancer (PCa). We aim to determine the current status of literature regarding the clinical outcomes among these minimally invasive therapies. A systematic search of PubMed, EMBASE, and the Cochrane Library for all English literature published from January 2001 to December 2019 was conducted to identify studies evaluating outcomes of CA, HIFU, IRE or VTP on PCa. Proportionality with 95% confidence intervals (CIs) was performed using STATA version 14.0. 56 studies consisting of 7383 participants were found to report data of interest and fulfilled the inclusion criteria in the final meta-analysis. The pooled proportions of positive biopsy after procedure were 20.0%, 24.3%, 24.2%, and 36.2% in CA, HIFU, IRE and VTP, respectively. The pooled proportions of BRFS were 75.7% for CA and 74.4% for HIFU. The pooled proportions of CSS were 96.1%, 98.2%, and 97.9% for CA, HIFU, and IRE, respectively. The pooled proportions of OS were 92.8% for CA and 85.2% for HIFU. The pooled proportions of FFS were 64.7%, 90.4%, and 76.7% for CA, IRE and VTP, respectively. The pooled proportions of MFS were 92.8% for HIFU and 99.1% for IRE. This meta-analysis shows that CA, HIFU, IRE, and VTP are promising therapies for PCa patients with similar clinical outcomes. However, further larger, well-designed randomized controlled trials are required to confirm this assertion.

Current state of image-guided focal therapy for prostate cancer

PURPOSE

To review the current evidence regarding protocols and outcomes of image-guided focal therapy (FT) for prostate cancer (PCa).

METHODS

A literature search of the latest published studies assessing primary FT for PCa was carried out in Medline and Cochrane library databases followed by a critical review. FT modalities, follow-up strategies, and oncological and toxicity outcomes were summarized and discussed in this review.

RESULTS

Twenty-four studies with six different sources of energy met the inclusion criteria. A heterogeneity of patient selection, energy sources, treatment templates, and definitions of failure was found among the studies. While a third of patients may be found to have additional cancer burden over 3-5 years following FT, most patients will remain free of a radical procedure. The vast majority of patients maintain urinary continence and good erectile function after FT. Acute urinary retention is the most common complication, whilst severe complications remain rare.

CONCLUSION

An increasing number of prospective studies with longer follow-up have been recently published. Acceptable cancer control and low treatment toxicity after FT have been consistently reported. Follow-up imaging and routine biopsy must be encouraged post-FT. While there is no reliable PSA threshold to predict failure after FT, reporting post-FT positive biopsies and retreatment rates appear to be standard when assessing treatment efficacy.

Effects of Focal vs Total Cryotherapy and Minimum Tumor Temperature on Patient-reported Quality of Life Compared With Active Surveillance in Patients With Prostate Cancer

OBJECTIVE

To investigate the effects of focal (hemiablation) or total cryotherapy and minimum tumor temperature on patient-reported quality of life (QoL) in patients with prostate cancer.

METHODS

An Institutional Review Board-approved database was reviewed for patients who underwent cryotherapy or active surveillance (AS). QoL questionnaire responses were collected and scores were analyzed for differences between focal and total cryotherapy and between very cold (<-76°C) and moderate-cold (≥-76°C) minimum tumor temperatures.

RESULTS

A total of 197 patients responded to a total of 547 questionnaires. Focal and total cryotherapy patients had initially lower sexual function scores relative to AS (year 1 mean difference focal: -31.7, P <.001; total: -48.1, P <.001). Focal cryotherapy was associated with a more rapid improvement in sexual function. Both focal and total cryotherapy sexual function scores were not statistically significantly different from the AS cohort by postprocedural year 4. Very cold and moderate-cold temperatures led to initially lower sexual function scores relative to AS (year 1 very cold: -38.1, P <.001; moderate-cold: -30.7, P <.001). Moderate-cold temperature scores improved more rapidly than those of very cold temperature. Neither very cold nor moderate-cold temperatures had a statistically significant difference in sexual function scores relative to AS by postprocedural year 4. Urinary function and bowel habits were not significantly different between focal and total cryotherapy and between very cold and moderate-cold temperature groups.

CONCLUSION

Focal cryotherapy and moderate-cold (≥-76°C) temperature were associated with favorable sexual function relative to total cryotherapy and very cold temperature, respectively. No significant differences in urinary function or bowel habits were observed between groups.

PSA kinetics following primary focal cryotherapy (hemiablation) in organ-confined prostate cancer patients

PURPOSE

We aim to evaluate prostate-specific antigen (PSA) trends in post-primary focal cryotherapy (PFC) patients.

MATERIALS AND METHODS

This was an institutional review board-approved retrospective study of PFC patients from 2010 to 2015. Patients with at least one post-PFC PSA were included in the study. Biochemical recurrence (BCR) was determined using the Phoenix criteria. PSA bounce was also assessed. We analyzed rates of change of PSA over time of post-PFC between BCR and no BCR groups. PSA-derived variables were analyzed as potential predictors of BCR.

RESULTS

A total of 104 PFC patients were included in our analysis. Median (range) age and follow-up time were 66 (48-82) years and 19 (6.3-38.6) months, respectively. Four (3.8%) patients experienced PSA bounce. The median percent drop in first post-PFC PSA of 80.0% was not associated with BCR (p = 0.256) and may indicate elimination of the index lesion. The rate of increase of PSA in BCR patients was significantly higher compared to patients who did not recur (median PSA velocity (PSAV): 0.15 vs 0.04 ng/ml/month, p = 0.001). Similar to PSAV (HR 9.570, 95% CI 3.725-24.592, p < 0.0001), PSA nadir ≥ 2 ng/ml [HR (hazard ratio) 1.251, 95% CI 1.100-1.422, p = 0.001] was independently associated with BCR.

CONCLUSION

A significant drop in post-PFC PSA may indicate elimination of the index lesion. Patients who are likely to recur biochemically have a significantly higher PSAV compared to those who do not recur. Nadir PSA of less than 2 ng/ml may be considered the new normal PSA in focal cryotherapy (hemiablation) follow-up.