Outcomes of salvage prostate cryotherapy stratified by pre-treatment PSA: update from the COLD registry

Risk Stratification of Patients with Recurrence After Primary Treatment for Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Biochemical recurrence (BCR) after primary definitive treatment for prostate cancer (PCa) is a heterogeneous disease state. While BCR is associated with worse oncologic outcomes, risk factors that impact outcomes can vary significantly, necessitating avenues for risk stratification. We sought to identify prognostic risk factors at the time of recurrence after primary radical prostatectomy or radiotherapy, and prior to salvage treatment(s), associated with adverse oncologic outcomes.

METHODS

We performed a systematic review of prospective studies in EMBASE, MEDLINE, and ClinicalTrials.gov (from January 1, 2000 to October 16, 2023) according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines (CRD42023466330). We reviewed the factors associated with oncologic outcomes among patients with BCR after primary definitive treatment.

KEY FINDINGS AND LIMITATIONS

A total of 37 studies were included (total n = 10 632), 25 after prostatectomy (total n = 9010) and 12 after radiotherapy (total n = 1622). Following recurrence after prostatectomy, factors associated with adverse outcomes include higher pathologic T stage and grade group, negative surgical margins, shorter prostate-specific antigen doubling time (PSADT), higher prostate-specific antigen (PSA) prior to salvage treatment, shorter time to recurrence, the 22-gene tumor RNA signature, and recurrence location on molecular imaging. After recurrence following radiotherapy, factors associated with adverse outcomes include a shorter time to recurrence, and shorter PSADT or higher PSA velocity. Grade group, T stage, and prior short-term hormone therapy (4-6 mo) were not clearly associated with adverse outcomes, although sample size and follow-up were generally limited compared with postprostatectomy data.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This work highlights the recommendations and level of evidence for risk stratifying patients with PCa recurrence, and can be used as a benchmark for personalizing salvage treatment based on prognostics.

PATIENT SUMMARY

We summarize the data from previously reported clinical trials on the topic of which factors predict worse cancer outcomes for patients who recur with prostate cancer after their initial treatment.

Achievable Dosimetric Constraints in Stereotactic Reirradiation for Recurrent Prostate Cancer

PURPOSE

Stereotactic body radiation therapy has been proposed as a salvage treatment for recurrent prostate cancer after irradiation. One crucial issue is choosing appropriate dose-volume constraints (DVCs) during planning. The objectives of this study were to (1) quantify the proportion of patients respecting the DVCs according to the Urogenital Tumor Study Group GETUG-31 trial, testing 36 Gy in six fractions, (2) explain geometrically why the DVCs could not be respected, and (3) propose the most suitable DVCs.

METHODS AND MATERIALS

This retrospective dosimetric analysis included 141 patients treated for recurrent prostate cancer with Cyberknife (Accuray), according to GETUG-31 DVCs: V95% ≥ 95% for the planning target volume (PTV), V12Gy < 20% and V27Gy < 2 cc for the rectum, and V12Gy < 15% and V27Gy < 5 cc for the bladder. The percentage of patients not respecting the DVCs was quantified. Correlations between the DVCs and anatomic structures were examined. New DVCs were proposed.

RESULTS

Only 19% of patients respected all DVCs, with a mean PTV of 18.5 cc (range, 3-48 cc), although the mean PTV was 40.5 cc (range, 3-174 cc) in the whole series. A total of 98% of the patients with a clinical target volume (CTV)/prostate ratio >0.5 could not respect the DVCs in the organs at risk. The target coverage and organ-at-risk sparing decreased significantly with increase in the values of PTV, CTV, CTV/prostate ratio, the overlapping volume between the PTV and bladder wall and between the PTV and rectal wall. Threshold values of PTV, >20 cc and 40 cc, allowed for the PTV and bladder DVCs, respectively. To improve DVC respect in case of large target volume, we proposed the following new DVCs: V12Gy < 25% and 25% and V27Gy < 2 cc and 5 cc for the rectum and bladder, respectively.

CONCLUSIONS

GETUG-31 DVCs are achievable only for small target volumes (CTV more than half of the prostate). For a larger target volume, new DVCs have been proposed.

Operative and Midterm Oncological Outcome of Focal Salvage Cryotherapy for Localized Prostate Cancer

BACKGROUND

Local recurrence after radiation therapy for prostate cancer is a major clinical issue. Various local treatments are available with mitigated functional and oncological outcomes. The aim of the present study was to evaluate perioperative and oncological results of salvage cryotherapy (CT) as treatment of local recurrence of prostate cancer.

METHODS

We retrospectively reviewed all patients treated with hemi-prostatic salvage CT for local recurrence of prostate cancer in 1 academic hospital between November 2011 and April 2019. Local recurrence was defined according to the Phoenix criteria (prostate-specific antigen [PSA] nadir + 2 ng/mL), associated with a prostatic MRI target lesion and confirmed by biopsy. Perioperative and functional complications were collected. Cox regression was conducted to assess factors associated with time to initiation of androgen deprivation therapy (ADT). Statistical analyses were conducted using R Studio.

RESULTS

A total of 29 patients were treated with an average follow-up of 37.6 months. Median age at CT was 77 years. Median PSA before CT was 5.1 ng/mL (min-max: 2.74-18). 17.2% of patients displayed a high D'Amico risk group. Median hospital stay was 1.4 days. Four patients (13.8%) experienced postoperative acute urinary retention. Nineteen patients (65.5%) experienced late functional complications (3 erectile dysfunctions, 3 stress incontinence, and 13 urinary frequency). Fourteen patients displayed recurrence after salvage treatment (48.2%). Median time to introduction of ADT was 15.1 months. ADT-free survival at 1 and 2 years was, respectively, 74% and 61%. In multivariate analysis, ISUP score 4 and PSA nadir <1 ng/mL after CT were significantly associated with time to ADT initiation.

CONCLUSIONS

Salvage focal CT may delay the use of ADT in locally recurrent prostate cancer after RT and offers an alternative for eligible patients. The technique was feasible with acceptable perioperative morbidity and acceptable midterm oncological outcome.

Salvage Low Dose Rate Prostate Brachytherapy: Clinical Outcomes of a Phase II Trial for Local Recurrence after External Beam Radiotherapy (NRG Oncology/xxxx)

PURPOSE

We report efficacy of a prospective Phase II trial (YYYY) of salvage low dose rate (LDR) prostate brachytherapy (BT) for local failure (LF) after prior external beam radiotherapy (EBRT) with minimum 5- years' follow up.

MATERIALS/METHODS

Eligible patients had low/intermediate risk prostate cancer (PCa) prior to EBRT and biopsy-proven LF > 30 months after EBRT, with PSA < 10 ng/mL and no regional/distant disease. The primary endpoint, late GI/GU Adverse Events (AEs) (CTCAE V3.0 ≥ Grade 3) was 14%. With minimum 5-year follow up after salvage BT, secondary clinical outcomes including disease-free (DFS; includes death from any cause), disease-specific (DSS), and overall survival (OS) were estimated using the Kaplan-Meier method and modelled using Cox proportional hazards regression. Local tumor progression (LF), distant and biochemical failure (DF/BF) were estimated using cumulative incidence. Time to LF, DF and BF were modeled by cause-specific Cox proportional hazards regression.

RESULTS

From 05/2007 -01/2014, 20 centers registered 100 patients (92 analyzable). Median follow up is 6.7 years (range: 0.3-11.2); median age 70 years (range: 55-82); median prior EBRT dose 74 Gy (IQR: 70-76) at a median of 85 months prior(IQR: 60-119). Androgen deprivation was combined with salvage BT in 16%. 10-year OS is 70% (95% confidence interval [CI]: 58 -83). 19 patients died (5 PCa, 10 other, 4 unknown). 10-year failure rates are local 5% (95% CI:1-11), distant 19% (95% CI:10-29) and biochemical 46% (95% CI:34-57). DFS is 61% at 5 years; 33% at 10 years. No baseline characteristic was significantly associated with any clinical outcome.

CONCLUSION

This is the first prospective multicenter trial reporting outcomes of salvage LDR BT for LF after EBRT. Five-year freedom from BF is 68%, comparable to other salvage modalities. Although further LF is rare (5%), BF climbs to 46% by10-years.

Minimally invasive strategies for the treatment of prostate cancer recurrence after radiation therapy: a systematic review

INTRODUCTION

The aim of this review was to conduct a comprehensive analysis of the role of minimally invasive salvage modalities in radio-recurrent prostate cancer and the associated clinical outcomes and toxicity profiles.

EVIDENCE ACQUISITION

A systematic review of the current literature was conducted through the Medline and NCBI PubMed, Scopus databases in January 2020. All papers published after 2000, concerning studies conducted on humans for radio-recurrent prostate cancer were considered for the review.

EVIDENCE SYNTHESIS

Overall, 545 studies were identified. After duplicate exclusion, initial screening, and eligibility evaluation, a total of 80 studies were included in the qualitative analysis, corresponding to a cohort of 6681 patients. The median age at initial diagnosis ranged from 59 to 75.5. Pre-treatment PSA ranged from 6.2 to 27.4 ng/mL. All patients underwent primary radiotherapy for localized prostate cancer. Cryotherapy, Brachytherapy, EBRT, HIFU were the minimally invasive options mostly used as salvage therapy. They showed to be promising approaches for recurrent prostate cancer (PCa) control, with acceptable toxicities.

CONCLUSIONS

Minimally invasive therapeutic options offer promising results in terms of biochemical control in the local recurrence setting. Unfortunately, the absence of high quality and comparative studies makes it difficult to establish which method is the best in terms of oncological and safety outcomes.

Salvage I-125 brachytherapy for locally-recurrent prostate cancer after radiotherapy

Purpose

Retrospective, single-institution analysis of clinical outcomes and treatment-related toxicity in patients treated with salvage I-125 low-dose rate (LDR) brachytherapy (BT) for locally-recurrent prostate cancer after radiotherapy.

Materials and methods

Between 2008 and 2018, 30 patients with biopsy-confirmed prostate cancer recurrence underwent salvage treatment with I-125 LDR-BT. Of these 30 patients, 14 were previously treated with primary external beam radiotherapy (EBRT; median dose, 73 Gy) and 16 with primary I-125 LDR-BT (145 Gy and 160 Gy in 14 and 2 cases, respectively). At seed implantation, the mean age was 75.8 years, with a median Gleason score of 7 and pre-salvage PSA of <10 ng/mL. Six patients received androgen deprivation therapy for six months after relapse diagnosis. The prescribed salvage I-125 BT dose to the gland was 120-130 Gy, with dose restrictions of Dmax <135% (urethra) and <100% (rectum). Toxicity was evaluated according to the CTCAE scale (v4.0).

Results

At a median follow-up of 45 months, the biochemical recurrence-free survival rates at 1, 3 and 5 years were 86.7%, 56.7% and 53.3%, respectively. Overall survival at 5 years was 87%. On the multivariate analysis, two variables were significant predictors of recurrence: PSA at relapse and nadir PSA post-salvage. Grade 3 genitourinary toxicity was observed in 5 patients (radiation-induced cystitis in 3 cases and urethral stenosis in 2) and G3 gastrointestinal toxicity in 3 patients (rectal bleeding).

Conclusion

Salvage therapy with I-125 brachytherapy is a safe and effective treatment option for locally-recurrent prostate cancer in previously-irradiated patients. High pre-salvage PSA and post-salvage nadir PSA values were significantly associated with a worse disease control after salvage I-125 LDR-BT. In well-selected patients, I-125 LDR-BT is comparable to other salvage therapies in terms of disease control and toxicity. However, more research is needed to determine the optimal management of locally-recurrent prostate cancer.

Salvage reirradiation for local prostate cancer recurrence after radiation therapy. For who? When? How?

PURPOSE

Literature review reporting results of salvage brachytherapy and stereotactic body radiotherapy for prostate recurrence only after radiotherapy for prostate cancer.

MATERIALS AND METHODS

A total of 38 studies (including at least 15 patients per study) were analysed: 19 using low-dose-rate brachytherapy, nine high-dose-rate brachytherapy and ten stereotactic body radiotherapy. Only five studies were prospective. The median numbers of patients were 30 for low-dose-rate brachytherapy, 34 for high-dose-rate brachytherapy, and 30 for stereotactic body radiotherapy. The median follow-up were 47months for low-dose-rate brachytherapy, 36months for high-dose-rate brachytherapy and 21months for stereotactic body radiotherapy.

RESULTS

Late genitourinary toxicity rates ranged, for grade 2: from 4 to 42% for low-dose-rate brachytherapy, from 7 to 54% for high-dose-rate brachytherapy and from 3 to 20% for stereotactic body radiotherapy, and for grade 3 or above: from 0 to 24% for low-dose-rate brachytherapy, from 0 to 13% for high-dose-rate brachytherapy and from 0 to 3% for grade 3 or above (except 12% in one study) for stereotactic body radiotherapy. Late gastrointestinal toxicity rates ranged, for grade 2: from 0 to 6% for low-dose-rate brachytherapy, from 0 to 14% for high-dose-rate brachytherapy and from 0 to 11% for stereotactic body radiotherapy, and for grade 3 or above: from 0 to 6% for low-dose-rate brachytherapy, and from 0 to 1% for high-dose-rate brachytherapy and stereotactic body radiotherapy. The 5-year biochemical disease-free survival rates ranged from 20 to 77% for low-dose-rate brachytherapy and from 51 to 68% for high-dose-rate brachytherapy. The 2- and 3-year disease-free survival rates ranged from 40 to 82% for stereotactic body radiotherapy. Prognostic factors of biochemical recurrence have been identified.

CONCLUSION

Despite a lack of prospective data, salvage reirradiation for prostate cancer recurrence can be proposed to highly selected patients and tumours. Prospective comparative studies are needed.

Nonsurgical Salvage Local Therapies for Radiorecurrent Prostate Cancer: A Systematic Review and Meta-analysis

CONTEXT

Different nonsurgical therapeutic strategies can be adopted for intraprostatic relapse of prostate cancer after primary radiotherapy, including re-irradiation (with brachytherapy [BT] or external beam radiotherapy [EBRT]), high-intensity focused ultrasound (HIFU), and cryotherapy. The main issues to consider when choosing nonsurgical salvage local therapies are local tumor control and significant genitourinary toxicity.

OBJECTIVE

To conduct a systematic review and meta-analysis of the role of nonsurgical salvage modalities in patients with radiorecurrent prostate cancer and associated clinical outcomes and toxicity profiles.

EVIDENCE ACQUISITION

We performed a critical review of the Medline, Scopus, and ClinicalKey databases from January 1, 2000 through February 1, 2018 according to the Preferred Reporting Items and Meta-Analyses statement. To assess the overall quality of the literature reviewed, we used a modified Delphi tool for case-series studies.

EVIDENCE SYNTHESIS

A total of 64 case-series studies were included, corresponding to a cohort of 5585 patients. The modified Delphi checklist evidenced high methodological quality overall (mean quality score of 80.6%). Biochemical control rates were lowest for patients treated with HIFU (58%, 95% confidence interval [CI] 47-68%) and highest for patients treated with BT (69%, 95% CI 62-76%) and EBRT (69%, 95% CI 53-83%). The lowest prevalence of incontinence was for patients treated with BT (3%, 95% CI 0-6%; I²=63.4%) and the highest was among patients treated with HIFU (28%, 95% CI 19-38%; I²=89.7%).

CONCLUSIONS

Nonsurgical therapeutic options, especially BT, showed good outcomes in terms of biochemical control and tolerability in the local recurrence setting.

PATIENT SUMMARY

The current analysis demonstrated that nonsurgical salvage local therapies offer a chance of a curative local approach in radiorecurrent prostate cancer. However, high-quality data from prospective trials are needed to validate long-term outcomes from nonsurgical strategies for the treatment of intraprostatic recurrence after previous radiotherapy.

Salvage high-dose-rate brachytherapy for prostate cancer persistence after brachytherapy: repeated use of a polyethylene glycol hydrogel spacer

Purpose

The aim of this study is to determine if a repeated hydrogel injection in a previously irradiated patient prior to salvage high-dose-rate brachytherapy (HDR-BT) is feasible.

Material and methods

A 61-year-old man with an organ confined (cT1c cN0 cM0, Gleason score 3 + 3 = 6, initial prostate-specific antigen [PSA] 7.9 ng/ml) prostate cancer was previously treated with HDR-BT (3 fractions of 11.5 Gy every 2^nd week) after hydrogel injection to reduce the rectal dose. Ten months after, an isolated local persistence was seen on a PSMA PET-CT. Nadir PSA was 2.0 ng/ml, 3 months after treatment and was 3.95 ng/ml by the re-treatment. Salvage therapy consisted of HDR-BT (3 fractions of 9 Gy every 2^nd week) with a simultaneous integrated boost to the residual region. Again, a hydrogel injection (10 ml) was applied to reduce the rectal dose prior to the treatment.

Results

Both hydrogel injection and salvage HDR-BT could be applied without any significant complications or toxicity. A good PSA response was observed with a nadir of 0.42 ng/ml, twelve months after salvage therapy. Acute toxicity (max grade II) resolved within 2 days after treatment.

Conclusions

The use of a hydrogel prior to salvage HDR-BT in a patient previously treated with HDR-BT is feasible and could help reduce the rectal exposure in the salvage setting.

Salvage Therapy Options for Local Prostate Cancer Recurrence After Primary Radiotherapy: a Literature Review

PURPOSE OF REVIEW

While recurrence after primary treatment of prostate cancer (PCa) is not uncommon, there is currently no consensus on the most appropriate management after radiation treatment failure. This article seeks to explore the currently utilized modalities for salvage treatment for radiorecurrent PCa. We focused our review on the oncologic outcomes and reported toxicity rates in the latest studies examining salvage radical prostatectomy (SRP), salvage cryotherapy (SCT), salvage high-intensity focused ultrasound (HIFU) and re-irradiation.

RECENT FINDINGS

There does not appear to be any significant difference in overall survival for more invasive salvage radical prostatectomy compared to the minimally invasive salvage approaches. Additionally, there seems to be a trend towards lower morbidity rates associated with minimally invasive and focal salvage treatment. We are encouraged by the results presented in this review and find that there is clearly a role for emerging minimally invasive and focal therapies as durable options for salvage treatment in patients with radiorecurrent PCa.

[SALVAGE CRYOABLATION TARGETING RECURRENT LESIONS AFTER DEFINITIVE RADIOTHERAPY FOR PROSTATE CANCER: IMPACT OF POST CRYOABLATION CHANGE IN URINARY AND SEXUAL FUNCTION]

(Purpose) To describe our initial experience in salvage cryoablation targeting recurrent lesions after definitive irradiation for prostate cancer. (Methods) Eligible patients for this treatment were those who developed biochemical failure after definitive radiotherapy for localized prostate cancer, but without distant metastasis, and with solid lesions identifiable on multiparametric magnetic resonance imaging (mpMRI). Histological proof of recurrence with mapping biopsy covering corresponding sites was obtained. Two to four cryoprobes were inserted transperineally into the prostate under general anesthesia with extensive lithotomy position. The rapid expansion of argon gas cryogen through a small opening within the cryoprobe cools itself to make an ice ball and the quick exchange to helium gas induces an active thawing phase. Entire procedure is monitored and guided with the use of transrectal ultrasonography. Postoperative follow-up included patient interview, digital rectal examination, prostate specific antigen (PSA) testing and quality of life (QOL) monitoring using IPSS and IIEF-5 at 1, 3, 6 and 12 months postoperatively. Changes of mpMRI findings with time, particularly at one month, were used to judge immediate treatment impact. (Results) Five patients underwent salvage cryoablation between October 2015 and September 2016. No grade 3/4 complications such as rectal fistula or urethral stenosis were experienced. Mean and maximal percent decline of PSA from baseline levels at 1, 3, 6 and 12 months following cryoablation were 72.2 and 94.7%, 79.4% and 93.9%, 78.2% and 92.1%, 79.6% and 90.9%, respectively. Posttreatment IPSS showed temporary worsening with average changes in score of 1.8, 1.5, 1.6, and 1.0 times over baseline levels, respectively. IPSS score returned to the baseline in one at six months and two at 12 months. Two of 5 patients were sexually active prior to therapy and thus evaluable. Both showed significant decline in IIEF score by 95% at 12 months. No patients showed any signs of recurrence. mpMRI at one month following cryoablation confirmed complete disappearance of visible lesions in all cases. (Conclusions) Salvage cryoablation for recurrent lesions of prostate cancer after definitive radiotherapy is feasible with minimal morbidity. Both oncological outcome and adverse events should be monitored carefully with longer follow up.

Assessment of Cryosurgical Device Performance Using a 3D Tissue-Engineered Cancer Model

As the clinical use of cryoablation for the treatment of cancer has increased, so too has the need for knowledge on the dynamic environment within the frozen mass created by a cryoprobe. While a number of factors exist, an understanding of the iceball size, critical isotherm distribution/penetration, and the resultant lethal zone created by a cryoprobe are critical for clinical application. To this end, cryoprobe performance is typically characterized based on the iceball size and temperature penetration in phantom gel models. Although informative, these models do not provide information as to the impact of heat input from surrounding tissue nor give any information on the ablative zone created. As such, we evaluated the use of a tissue-engineered tumor model (TEM) to assess cryoprobe performance including iceball size, real-time thermal profile distribution, and resultant ablative zone. Studies were conducted using an Endocare V-probe cryoprobe, with a 10/5/10 double freeze–thaw protocol using prostate and renal cancer TEMs. The data demonstrate the generation of a 33- to 38-cm3 frozen mass with the V-Probe cryoprobe following the double freeze of which ∼12.7 and 6.5 cm3 was at or below −20°C and −40°C, respectively. Analysis of ablation zone using fluorescence microscopy 24 hours postthaw demonstrated that the internal ∼40% of the frozen mass was completely ablated, whereas in the periphery of the iceball (outer 1 cm region), a gradient of partial to minimal destruction was observed. These findings correlated well with clinical reports on renal and prostate cancer cryoablation. Overall, this study demonstrates that TEMs provide an effective model for a more complete characterization of cryoablation device performance. The data demonstrate that while the overall iceball size generated in the TEM was consistent with published reports from phantom models, the integration of an external heat load, circulation, and cellular components more closely reflect an in vivo setting and the impact of penetration of the critical (−20°C and −40°C) isotherms into the tissue. This is important as it is well appreciated in clinical practice that the heat load of a tissue, cryoprobe proximity to vasculature, and so on, can impact outcome. The TEM model provides a means of characterizing the impact on ablative dose delivery allowing for a better understanding of probe performance and potential impact on ablative outcome.

MRI-guided focal therapy of prostate cancer

With the advent of focal therapy as a recognized treatment option for men with prostate cancer, there are a host of emerging interventions that take advantage of MRI for image guidance. Focal therapy affords a middleground option for patients with low- to intermediate-grade prostate cancer by providing a means of keeping their cancer at bay while avoiding the negative consequences of radical therapies. However, the practice of focal treatment is far from straightforward, with some believing focal treatment errs on the side of overtreatment among patients with low-grade cancer; others worry it is undertreatment in potentially significant multifocal disease. Further research is necessary, both relating to focal therapy in general and to the utility of each MRI-guided focal treatment discussed.

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.

Decision analytic cost-effectiveness model to compare prostate cryotherapy to androgen deprivation therapy for treatment of radiation recurrent prostate cancer

OBJECTIVE

To determine the cost-effectiveness of salvage cryotherapy (SC) in men with radiation recurrent prostate cancer (RRPC).

DESIGN

Cost-utility analysis using decision analytic modelling by a Markov model.

SETTING AND METHODS

Compared SC and androgen deprivation therapy (ADT) in a cohort of patients with RRPC (biopsy proven local recurrence, no evidence of metastatic disease). A literature review captured published data to inform the decision model, and resource use data were from the Scottish Prostate Cryotherapy Service. The model was run in monthly cycles for RRPC men, mean age of 70 years. The model was run over the patient lifetime, to assess changes in patient health states and the associated quality of life, survival and cost impacts. Results are reported in terms of the discounted incremental costs and discounted incremental quality-adjusted life years (QALYs) gained between the 2 alternative interventions. Probabilistic sensitivity analysis used a 10,000 iteration Monte Carlo simulation.

RESULTS

SC has a high upfront treatment cost, but delays the ongoing monthly cost of ADT. SC is the dominant strategy over the patient lifetime; it is more effective with an incremental 0.56 QALY gain (95% CI 0.28 to 0.87), and less costly with a reduced lifetime cost of £29,719 (€37,619) (95% CI -51,985 to -9243). For a ceiling ratio of £30,000, SC has a 100% probability to be cost-effective. The cost neutral point was at 3.5 years, when the upfront cost of SC (plus any subsequent cumulative cost of side effects and ADT) equates the cumulative cost in the ADT arm. Limitations of our model may arise from its insensitivity to parameter or structural uncertainty.

CONCLUSIONS

The platform for SC versus ADT cost-effective analysis can be employed to evaluate other treatment modalities or strategies in RRPC. SC is the dominant strategy, costing less over a patient's lifetime with improvements in QALYs.

TRIAL REGISTRATION NUMBER

This economic analysis was undertaken as part of the CROP RCT study

ISRCTN

72677390; it was a pre-trial economic model developed and analysed during the pre-results stage of the RCT.

Comparative Oncologic and Toxicity Outcomes of Salvage Radical Prostatectomy Versus Nonsurgical Therapies for Radiorecurrent Prostate Cancer: A Meta-Regression Analysis

CONTEXT

In the absence of randomised controlled trials comparing the oncologic, toxicity, and functional outcomes of salvage radical prostatectomy (SRP), salvage high-intensity focused ultrasound (SHIFU), salvage brachytherapy (SBT), and salvage cryotherapy (SCT), controversy exists as to the optimal salvage modality in radiorecurrent prostate cancer.

OBJECTIVE

We carried out a meta-regression analysis to determine whether there is a difference in oncologic, toxicity, and functional outcomes using data from original publications of salvage modalities in the postradiation setting.

EVIDENCE ACQUISITION

We performed a systematic review of PubMed/Medline citations according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. We included 63 articles in the analysis (25 on SRP, 8 on SHIFU, 16 on SCT, 14 on SBT).

EVIDENCE SYNTHESIS

Median values of the following variables were extracted from each study: patient age, length of follow-up, prostate-specific antigen (PSA) before radiotherapy (RT), PSA before salvage therapy, Gleason score before RT, and time interval between RT and salvage therapy. Functional, toxicity, and oncologic outcomes were measured according to rates of impotence, incontinence, fistula formation, urethral strictures, and biochemical recurrence. Meta-regression adjusting for confounders found no significant difference in oncologic outcomes between SRP and nonsurgical salvage modalities. SBT, SCT, and SHIFU appeared to have better continence outcomes than SRP. No significant difference in toxicity outcomes between modalities was found, although limitations such as reporting, selection, and publication bias and between-study heterogeneity must also be considered with these conclusions.

CONCLUSIONS

Oncologic outcomes are comparable for SRP and all three nonsurgical salvage modalities. We found no significant differences in toxicity outcomes among modalities; however, SRP appears to be associated with worse rates of urinary incontinence than SBT, SCT, and SHIFU.

PATIENT SUMMARY

We performed a meta-regression analysis to compare oncologic, functional, and toxicity outcomes between salvage radical prostatectomy and nonsurgical salvage modalities. Oncologic and toxicity outcomes appear to be similar; however, all nonsurgical salvage modalities may be associated with better continence outcomes.

Re-purposing cryoablation: a combinatorial 'therapy' for the destruction of tissue

It is now recognized that the tumor microenvironment creates a protective neo-tissue that isolates the tumor from the various defense strategies of the body. Evidence demonstrates that, with successive therapeutic attempts, cancer cells acquire resistance to individual treatment modalities. For example, exposure to cytotoxic drugs results in the survival of approximately 20-30% of the cancer cells as only dividing cells succumb to each toxic exposure. With follow-up treatments, each additional dose results in tumor-associated fibroblasts secreting surface-protective proteins, which enhance cancer cell resistance. Similar outcomes are reported following radiotherapy. These defensive strategies are indicative of evolved capabilities of cancer to assure successful tumor growth through well-established anti-tumor-protective adaptations. As such, successful cancer management requires the activation of multiple cellular 'kill switches' to prevent initiation of diverse protective adaptations. Thermal therapies are unique treatment modalities typically applied as monotherapies (without repetition) thereby denying cancer cells the opportunity to express defensive mutations. Further, the destructive mechanisms of action involved with cryoablation (CA) include both physical and molecular insults resulting in the disruption of multiple defensive strategies that are not cell cycle dependent and adds a damaging structural (physical) element. This review discusses the application and clinical outcomes of CA with an emphasis on the mechanisms of cell death induced by structural, metabolic, vascular and immune processes. The induction of diverse cell death cascades, resulting in the activation of apoptosis and necrosis, allows CA to be characterized as a combinatorial treatment modality. Our understanding of these mechanisms now supports adjunctive therapies that can augment cell death pathways.

Salvage focal prostate cryoablation for locally recurrent prostate cancer after radiotherapy: initial results from the cryo on-line data registry

BACKGROUND

Several investigators have tried to apply salvage focal prostate cryoablation to small numbers of patients with biopsy-proven unilateral recurrent prostate cancer (PCa) after radiotherapy with the aim of decreasing complications of salvage cryoablation. We report contemporary outcomes of salvage focal cryoablation for locally recurrent PCa after radiotherapy within the Cryo On-Line Data (COLD) Registry.

METHODS

We queried the COLD Registry to identify patients diagnosed as locally recurrent PCa after radiotherapy and treated with salvage focal cryoablation. Patients with hormone ablation after cryotherapy were excluded. The biochemical disease-free survival and morbidities were analyzed. Biochemical failure was defined using the Phoenix definition.

RESULTS

From 2002 to 2012, 91 patients with biopsy-proven radio-recurrent PCa underwent salvage focal cryoablation with curative intent. The biochemical disease-free survival rates were 95.3%, 72.4%, and 46.5% at 1, 3, and 5 years, respectively. Positive biopsies after salvage focal cryoablation were observed in four of 14 patients who underwent biopsy (28.6%). Rectourethral fistula was observed in three cases (3.3%). Urinary retention was observed in six cases (6.6%). Incontinence (requiring pad use) was reported in five cases (5.5%). Intercourse was reported in 10 of 20 patients (50%) who reported potency before salvage focal cryoablation.

CONCLUSIONS

The outcomes from this observational study indicate that salvage focal cryoablation can be an effective treatment with encouraging potency preservation for patients with locally recurrent PCa after radiotherapy. However, other morbidity including rectourethral fistula and incontinence are not clearly lower than for patients treated with salvage whole gland cryoablation. Studies with longer follow-up, more patients, and direct comparison to salvage whole gland cryoablation are needed before recommending salvage focal cryoablation as a standard treatment option for these patients.

Feasibility study of a randomised controlled trial to compare (deferred) androgen deprivation therapy and cryotherapy in men with localised radiation-recurrent prostate cancer

BACKGROUND

Salvage therapeutic options for biochemical failure after primary radiation-based therapy include radical prostatectomy, cryoablation, high-intensity focused ultrasound (HIFU), brachytherapy (for post-EBRT patients) and androgen deprivation therapy (ADT). ADT and salvage prostate cryoablation (SPC) are two commonly considered treatment options for RRPC. However, there is an urgent need for high-quality clinical studies to support evidence-based decisions on treatment choice. Our study aims to determine the feasibility of randomising men with RRPC for treatment with ADT and SPC.

METHODS

The randomised controlled trial (CROP) was developed, which incorporated protocols to assess parameters relating to cryotherapy procedures and provide training workshops for optimising patient recruitment. Analysis of data from the recruitment phase and patient questionnaires was performed.

RESULTS

Over a period of 18 months, 39 patients were screened for eligibility. Overall 28 patients were offered entry into the trial, but only 7 agreed to randomisation. The majority reason for declining entry into the trial was an unwillingness to be randomised into the study. 'Having the chance of getting cryotherapy' was the major reason for accepting the trial. Despite difficulty in retrieving cryotherapy temperature parameters from prior cases, 9 of 11 cryotherapy centres progressed through the Cryotherapists Qualification Process (CQP) and were approved for recruiting into the CROP study.

CONCLUSIONS

Conveying equipoise between the two study arms for a salvage therapy was challenging. The use of delayed androgen therapy may have been seen as an inferior option. Future cohort studies into available salvage options (including prostate cryotherapy) for RRPC may be more acceptable to patients than randomisation within an RCT.

Prostate gland lengths and iceball dimensions predict micturition functional outcome following salvage prostate cryotherapy in men with radiation recurrent prostate cancer

INTRODUCTION

Tissue cryoablation is a potential curative option for solid malignancies, including radiation recurrent prostate cancer (RRPC). Case series of salvage cryotherapy (SCT) in RRPC have reported promising disease free survival (DFS) outcomes and acceptable toxicity profile. While many men receive SCT, no predictive factors for treatment induced side effects are known. The aim of this study is to validate the oncologic outcome of SCT in a large multi-centre patient cohort and to identify potential parameters associated with an increased risk of micturition symptoms.

PATIENTS AND METHODS

In this retrospective analysis, we studied 283 consecutive patients with RRPC treated by SCT in three independent U.K. centres (between 2001 and 2011). Two freeze-thaw cycles of transperineal cryotherapy were performed under transrectal ultrasound guidance by a single surgeon in each of the 3 sites. We analysed clinico-pathological factors against tumour response. Functional outcomes were assessed by continence status and IPSS questionnaire. Predictive factors for SCT-induced micturition symptoms were analysed in a sub-group (n=42) of consecutive cases.

RESULTS

We found that nadir post-SCT PSA levels strongly associated with DFS. The DFS rates at 12- and 36-month were 84% and 67% for the ≤ 1 ng/ml group and 56% and 14% for the >1 ng/ml group, respectively (p<0.001). Correlative analysis revealed highly significant association between patients' post-SCT micturition status with prostate gland and iceball lengths following SCT. Finally, in a reduction model, both gland length and maximal length of iceball were highly associated with patients' IPSS outcome (p<0.001).

CONCLUSION

We report the largest European patient cohort treated with SCT for RRPC. Oncologic outcome guided by nadir PSA of <1 ng/ml is consistent with earlier single-centre series. For the first time, we identified physical parameters to predict micturition symptoms following SCT. Our data will directly assist on-going and future trial design in cryotherapy in prostate cancer.

The role of prostate-specific antigen in light of new scientific evidence

OBJECTIVE

Review the scientific evidence acquired in recent years on Prostate-Specific Antigen (PSA).

ACQUISITION OF EVIDENCE

Analysis of the available evidence on the current role of PSA, according to a panel of experts who recorded their experience on the subject.

SUMMARY OF THE EVIDENCE

Currently, PSA cannot be considered solely an indicator of the presence or absence of prostate cancer. Rather, the determination of PSA assists the urologist in indicating the most appropriate treatment for a patient with benign prostatic hypertrophic (BPH), as well as in suspecting a prostatic tumour when the PSA reading increases >0,3 ng/ml, in patients treated with 5-alpha-reductase inhibitor, over the reading achieved at six months of having initiated this treatment. Moreover, PSA is a key factor in the follow-up of patients with prostate adenocarcinoma who undergo surgery, radiation therapy or minimally invasive techniques. PSA helps to define biochemical recurrence, suggest the existence of a local or distal recurrence and propose or rule out adjuvant therapies.

CONCLUSIONS

New data on the current role of PSA in the management of patients treated for BPH and/or prostate cancer should be taken into account.

Management of biochemical recurrence after primary treatment of prostate cancer: a systematic review of the literature

CONTEXT

Despite excellent cancer control with the treatment of localized prostate cancer (PCa), some men will experience a recurrence of disease. The optimal management of recurrent disease remains uncertain.

OBJECTIVE

To systematically review recent literature regarding management of biochemical recurrence after primary treatment for localized PCa.

EVIDENCE ACQUISITION

A comprehensive systematic review of the literature was performed from 2000 to 2012 to identify articles pertaining to management after recurrent PCa. Search terms included prostate cancer recurrence, salvage therapy, radiorecurrent prostate cancer, post HIFU, post cryoablation, postradiation, and postprostatectomy salvage. Studies were selected according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and required to provide a comprehensive description of primary and secondary treatments along with outcomes.

EVIDENCE SYNTHESIS

The data from 32 original publications were reviewed. The most common option for local salvage therapy after radical prostatectomy (RP) was radiation. Options for local salvage therapy after primary radiation included RP, brachytherapy, and cryotherapy. Different definitions of recurrence and risk profiles among patients make comparative assessment among salvage treatment modalities difficult. Triggers for intervention and factors predicting response to salvage therapy vary.

CONCLUSIONS

Radiation therapy (RT) after RP can provide durable prostate-specific antigen (PSA) responses in a sizeable percentage of men, especially when given early (ie, PSA <1 ng/ml). Though a few studies suggest improvements in mortality, prospective randomized trials are needed and underway. The role of salvage treatment after RT is less clear.