Management of recurrent prostate cancer after radiotherapy: long-term results from CALGB 9687 (Alliance), a prospective multi-institutional salvage prostatectomy series

A Phase 1 Trial of Salvage Stereotactic Body Radiation Therapy for Radiorecurrent Prostate Cancer After Brachytherapy

PURPOSE

NCT03253744 is a phase 1 trial with the primary objective to identify the maximum tolerated dose (MTD) of salvage stereotactic body radiation therapy (SBRT) in patients with local prostate cancer recurrence after brachytherapy. Additional objectives included biochemical control and imaging response.

METHODS AND MATERIALS

This trial was initially designed to test 3 therapeutic dose levels (DLs): 40 Gy (DL1), 42.5 Gy (DL2), and 45 Gy (DL3) in 5 fractions. Intensity modulation was used to deliver the prescription dose to the magnetic resonance imaging and prostate-specific membrane antigen-based positron emission tomography imaging-defined gross tumor volume while simultaneously delivering 30 Gy to an elective volume defined by the prostate gland. This phase 1 trial followed a 3+3 design with a 3-patient expansion at the MTD. Toxicities were scored until trial completion at 2 years post-SBRT using Common Terminology Criteria for Adverse Events version 5.0. Escalation was halted if 2 dose limiting toxicities occurred, defined as any persistent (>4 days) grade 3 toxicity occurring within the first 3 weeks after SBRT or any grade ≥3 genitourinary (GU) or grade 4 gastrointestinal toxicity thereafter.

RESULTS

Between August 2018 and January 2023, 9 patients underwent salvage SBRT and were observed for a median of 22 months (Q1-Q3, 20-43 months). No grade 3 to 5 adverse events related to study treatment were observed; thus, no dose limiting toxicities occurred during the observation period. Escalation was halted by amendment given excellent biochemical control in DL1 and DL2 in the setting of a high incidence of clinically significant late grade 2 GU toxicity. Therefore, the MTD was considered 42.5 Gy in 5 fractions (DL2). One- and 2-year biochemical progression-free survival were 100% and 86%, representing a single patient in the trial cohort with biochemical failure (prostate-specific antigen [PSA] nadir + 2.0) at 20 months posttreatment.

CONCLUSIONS

The MTD of salvage SBRT for the treatment of intraprostatic radiorecurrence after brachytherapy was 42.5 Gy in 5 fractions producing an 86% 2-year biochemical progression-free survival rate, with 1 poststudy failure at 20 months. The most frequent clinically significant toxicity was late grade 2 GU toxicity.

Salvage Radical Prostatectomy for Recurrent Prostate Cancer: A Systematic Review (French ccAFU)

The aim of this study was to systematically review the current evidence regarding the oncological and functional outcomes of salvage radical prostatectomy (sRP) for recurrent prostate cancer. A systematic review was conducted throughout September 2022 using the PubMed, Science Direct, Scopus, and Embase databases. Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed to identify eligible studies. A total of 55 studies (3836 patients) met our eligibility criteria. The vast majority of men included had radiation therapy (including brachytherapy) as their first-line treatment (n = 3240, 84%). Other first-line treatments included HIFU (n = 338, 9%), electroporation (n = 59, 2%), proton beam therapy (n = 54, 1.5%), cryotherapy (n = 34, 1%), focal vascular targeted photodynamic therapy (n = 22, 0.6%), and transurethral ultrasound ablation (n = 19, 0.5%). Median preoperative PSA, at the time of recurrence, ranged from 1.5 to 14.4 ng/mL. The surgical approach was open in 2300 (60%) cases, robotic in 1465 (38%) cases, and laparoscopic in 71 (2%) cases. Since 2019, there has been a clear increase in robotic versus conventional surgery (1245 versus 525 cases, respectively). The median operative time and blood loss ranged from 80 to 297 min and 75 to 914 mL, respectively. Concomitant lymph node dissection was performed in 2587 cases (79%). The overall complication rate was 34%, with a majority of Clavien grade I or II complications. Clavien ≥ 3 complications ranged from 0 to 64%. Positive surgical margins were noted in 792 cases (32%). The median follow-up ranged from 4.6 to 94 months. Biochemical recurrence after sRP ranged from 8% to 51.5% at 12 months, from 0% to 66% at 22 months, and from 48% to 59% at 60 months. The specific and overall survival rates ranged from 13.4 to 98% and 62 to 100% at 5 years, respectively. Urinary continence was maintained in 52.1% of cases. sRP demonstrated acceptable oncological outcomes. These results, after sRP, are influenced by several factors, and above all by pre-treatment assessment, including imaging, with the development of mpMRI and metabolic imaging. Our results demonstrated that SRP can be considered a suitable treatment option for selected patients, but the level of evidence remains low.

Salvage Cryoablation for Recurrent Prostate Cancer Following Primary External Beam Radiotherapy or Primary Cryotherapy: A Propensity Score Matched Analysis of Mid-term Oncologic and Functional Outcomes

INTRODUCTION

Local prostate cancer recurrence following radiotherapy (XRT) or cryoablation (CRYO) may be addressed with salvage cryotherapy (SCT), although little is known about how the primary treatment modality affects SCT results. Oncologic and functional outcomes of patients who underwent SCT after primary XRT (XRT-SCT) or cryoablation (CRYO-SCT) were studied.

METHODS

Data was collected using the Duke Prostate Cancer database and the Cryo On-Line Data (COLD) registry. The primary outcome was biochemical progression-free survival (BPFS).  Urinary incontinence, rectourethral fistula, and erectile dysfunction were secondary outcomes. The Kaplan-Meier log-rank test and univariable/multivariable Cox proportional hazards (CPH) models were utilized to evaluate BPFS between groups.

RESULTS

419 XRT-SCT and 63 CRYO-SCT patients met inclusion criteria, that was reduced to 63 patients in each cohort after propensity matching. There was no difference in BPFS at 2 and 5 years both before (P = .5 and P = .7) and after matching (P = .6 and P = .3). On multivariable CPH, BPFS was comparable between treatment groups (CRYO-SCT, HR=1.1, [0.2-2.2]).  On the same analysis, BPFS was lower in D'Amico high-risk (HR 3.2, P < .01) and intermediate-risk (HR 1.95, P < .05) categories compared to low-risk. There was no significant difference in functional outcomes between cohorts.

CONCLUSION

Following primary cryotherapy, salvage cryoablation provides comparable intermediate oncological outcomes and functional outcomes compared to primary radiotherapy.

The Role of Salvage Radical Prostatectomy in Patients with Radiation-Resistant Prostate Cancer

There are multiple treatment strategies for patients with localized prostate adenocarcinoma. In intermediate- and high-risk patients, external beam radiation therapy demonstrates effective long-term cancer control rates comparable to radical prostatectomy. In patients who opt for initial radiotherapy but have a local recurrence of their cancer, there is no unanimity on the optimal salvage approach. The lack of randomized trials comparing surgery to other local salvage therapy or observation makes it difficult to ascertain the ideal management. A narrative review of existing prospective and retrospective data related to salvage radical prostatectomy after radiation therapy was undertaken. Based on retrospective and prospective data, post-radiation salvage radical prostatectomy confers oncologic benefits, with overall survival ranging from 84 to 95% at 5 years and from 52 to 77% at 10 years. Functional morbidity after salvage prostatectomy remains high, with rates of post-surgical incontinence and erectile dysfunction ranging from 21 to 93% and 28 to 100%, respectively. Factors associated with poor outcomes after post-radiation salvage prostatectomy include preoperative PSA, the Gleason score, post-prostatectomy staging, and nodal involvement. Salvage radical prostatectomy represents an effective treatment option for patients with biochemical recurrence after radiotherapy, although careful patient selection is important to optimize oncologic and functional outcomes.

The potential of low-dose-rate brachytherapy with iodine-125 in the treatment of local recurrences of prostate cancer after primary high-dose-rate monotherapy

Purpose

The incidence of local prostate cancer recurrences after monotherapy with high-dose-rate brachytherapy (HDR-BT) is low. However, a cumulated number of local recurrences during follow-up is naturally observed in highly specialized oncological centers. This retrospective study aimed to present the treatment of local recurrences after HDR-BT with low-dose-rate brachytherapy (LDR-BT).

Material and methods

Nine patients with low- and intermediate-risk prostate cancer with a median age of 71 years (range, 59-82 years) were diagnosed with local recurrences after previous monotherapy HDR-BT, 3 × 10.5 Gy (from 2010 to 2013). Median time to biochemical recurrence was 59 months (range, 21-80 months). All patients received 145 Gy with salvage LDR-BT (iodine-125). Gastrointestinal and urological toxicities were evaluated based on patients' records following CTCAE v. 4.0 and IPSS scales.

Results

The median follow-up after salvage treatment was 30 months (range, 17-63 months). Local recurrences (LR) were detected in two cases, and the actuarial 2-year local control was 88%. Biochemical failure was observed in four cases. Distant metastases (DM) were observed in 2 patients. In one patient, both LR and DM were diagnosed simultaneously. Four patients had no relapse of the disease, and a 2-year disease-free survival (DSF) was 58.3%. Before salvage treatment, median IPSS scores were 6.5 points (range, 1-23 points). At the first follow-up visit, after one month, the mean IPSS score was 20 points, and at the last follow-up visit, it was 8 points (range, 1-26 points). One patient had urinary retention after treatment. There was no significant change in IPSS scores before and after the treatment (p = 0.68). Two patients had grade 1 toxicity in the gastrointestinal tract.

Conclusions

Salvage LDR-BT for patients with prostate cancer previously treated with HDR-BT monotherapy is characterized by acceptable toxicity, and may result in local disease control.

Enrichment of "Cribriform" morphologies (intraductal and cribriform adenocarcinoma) and genomic alterations in radiorecurrent prostate cancer

Locally relapsed prostate cancer (PCa) after radiation therapy (RT) is associated with substantial morbidity and mortality. Morphological and molecular consequences that may contribute to RT resistance and local recurrence remain poorly understood. Locally recurrent PCa tissue from 53 patients with clinically localized PCa who failed with primary RT and subsequently underwent salvage radical prostatectomy (RP) was analyzed for tumor focality, clinicopathological, molecular, and genomic characteristics. Targeted next-generation sequencing with full exon coverage of 1,425 cancer-related genes was performed on 10 representative radiorecurrent PCas exhibiting no RT effect with matched adjacent benign prostate tissue. At RP, 37 (70%) of PCas had no RT effect with the following characteristics: grade group (GG) ≥ 3 (70%), unifocal tumor (75%), extraprostatic disease (78%), lymph node metastasis (8%), and "cribriform" morphologies (84%) [cribriform PCa (78%) or intraductal carcinoma (IDC-P) (61%)] at a median percentage of approximately 80% of tumor volume. In the setting of multifocal tumors (25%) at RP, the cribriform morphologies were restricted to index tumors. Of 32 patients with available pre-RT biopsy information, 16 had GG1 PCa, none had cribriform morphologies at baseline but 81% demonstrated cribriform morphologies at RP. Notable alterations detected in the sequenced tumors included: defects in DNA damage response and repair (DDR) genes (70%) (TP53, BRCA2, PALB2, ATR, POLQ), PTEN loss (50%), loss of 8p (80%), and gain of MYC (70%). The median tumor mutational burden was 4.18 mutations/Mb with a range of 2.16 to 31.86. Our findings suggest that most radiorecurrent PCas are enriched in cribriform morphologies with potentially targetable genomic alterations. Understanding this phenotypic and genotypic diversity of radiorecurrent PCa is critically important to facilitate optimal patient management.

Focal therapy for primary and salvage prostate cancer treatment: a narrative review

Despite innovations in surgical technology and advancements in radiation therapy, radical treatments for clinically localized prostate cancer are associated with significant patient morbidity, including both urinary and sexual dysfunction. This has created a vital need for therapies and management strategies that provide an acceptable degree of oncologic efficacy while mitigating these undesirable side effects. Successful developments in screening approaches and advances in prostate imaging have allowed clinicians to identify, localize, and more precisely target early cancers. This has afforded urologists with an important opportunity to develop and employ focal ablation techniques that selectively destroy tumors while preserving the remainder of the gland, thus avoiding detrimental treatment effects to surrounding sensitive structures. A lack of high-level evidence supporting such an approach had previously hindered widespread adoption of focal treatments, but there are now numerous published clinical trials which have sought to establish benchmarks for safety and efficacy. As the clinical evidence supporting a potential role in prostate cancer treatment begins to accumulate, there has been a growing acceptance of focal therapy in the urologic oncology community. In this narrative review article, we describe the techniques, advantages, and side effect profiles of the most commonly utilized focal ablative techniques and analyze published clinical trial data supporting their evolving role in the prostate cancer treatment paradigm.

Salvage re-irradiation using stereotactic body radiation therapy for locally recurrent prostate cancer: the impact of castration sensitivity on treatment outcomes

Background

Advances in imaging, biomaterials and precision radiotherapy provide new opportunities to salvage locally recurrent prostate cancer (PC). This study evaluates the efficacy and safety of re-irradiation using stereotactic body radiation therapy (SBRT). We hypothesized that patients with castrate-resistant PC (CRPC) would benefit less from local salvage.

Methods

A prospective clinical database was reviewed to extract 30 consecutive patients treated with prostate re-irradiation. Gallium prostate specific membrane antigen (PSMA) ligand positron emission tomography was performed following prostate-specific antigen failure in all patients and biopsy was obtained in 18 patients (60%). Re-irradiation was either focal (n = 13) or whole-gland (n = 17). Endo-rectal balloons were used in twenty-two patients and hydrogel spacers in eight patients. The median prescription dose was 5 fractions of 6.5 (range: 6–8) Gray (Gy).

Results

Median follow-up was 28 months. Failure occurred in 10 (out of 11) CRPC patients versus 6 (out of 19) castrate-sensitive patients (91% vs. 32%, p = 0.008) after a median of 13 and 23 months, respectively. Metastases occurred in 64% (n = 7) of CRPC patients versus 16% (n = 3) of castrate-sensitive patients (p = 0.007). Two patients experienced local in-field recurrence, thus local control was 93%. The 2 and 3-year recurrence-free survival were 84% and 79% for castrate-sensitive patients versus 18% and 9% for CRPC patients (p < 0.001), and 3-year metastasis-free survival was 90% versus 27% (p < 0.01) for castrate-sensitive and CRPC patients, respectively. Acute grade II and III genitourinary (GU) toxicity occurred in 27% and 3%, and late GU toxicity in 30% and 3%, respectively. No ≥ grade II acute gastrointestinal (GI) toxicity occurred, and only one patient (3%) developed late grade II toxicity.

Conclusions

Early delivery of salvage SBRT for local recurrence is associated with excellent 3-year disease control and acceptable toxicity in the castrate-sensitive phenotype. PSMA imaging for detection of local recurrence and the use of precision radiotherapy with rectal protective devices should be further investigated as a novel salvage strategy for radio-recurrent PC.

Functional Outcomes after Local Salvage Therapies for Radiation-Recurrent Prostate Cancer Patients: A Systematic Review

PURPOSE

To assess the rate and severity of functional outcomes after salvage therapy for radiation recurrent prostate cancer.

METHODS

This systematic review of the MEDLINE/PubMed database yielded 35 studies, evaluating salvage radical prostatectomy (RP), brachytherapy (BT), high-intensity focal ultrasound (HIFU) and cryotherapy (CT) after failure of primary radiation therapy. Data on pre- and post-salvage rates and severity of functional outcomes (urinary incontinence, erectile dysfunction, and lower urinary tract symptoms) were collected from each study.

RESULTS

The rates of severe urinary incontinence ranged from 28-88%, 4.5-42%, 0-6.5%, 2.4-8% post salvage RP, HIFU, CT and BT, respectively. The rates of erectile dysfunction were relatively high reaching as much as 90%, 94.6%, 100%, 62% following RP, HIFU, CT and BT, respectively. Nonetheless, the high pre-salvage rates of ED preclude accurate estimation of the effect of salvage therapy. There was an increase in the median IPSS following salvage HIFU, BT and CT ranging from 2.5-3.4, 3.5-12, and 2, respectively. Extended follow-up showed a return-to-baseline IPSS in a salvage BT study. The reported data suffer from selection, reporting, publication and period of study biases, making inter-study comparisons inappropriate.

CONCLUSIONS

local salvage therapies for radiation recurrent PCa affect continence, lower urinary tract symptoms and sexual functions. The use of local salvage therapies may be warranted in the setting of local disease control, but each individual decision must be made with the informed patient in a shared decision working process.

Salvage low dose rate brachytherapy for prostate cancer recurrence following definitive external beam radiation therapy

PURPOSE

We sought to describe the safety and efficacy of salvage low dose rate (LDR) brachytherapy for local prostate cancer recurrence following definitive RT.

MATERIALS AND METHODS

We included patients from two prospectively maintained institutional databases who underwent salvage LDR brachytherapy for biopsy confirmed intra-prostatic recurrence following primary RT. All patients were without evidence of metastatic disease. Freedom from biochemical failure (FFbF), prostate cancer specific survival (PCaSS), and overall survival (OS) were determined using the Kaplan-Meier estimates. Cox proportional hazard models were used to identify factors predictive of FFbF. Toxicity was graded by Common Terminology Criteria for Adverse Events (CTCAE) v5.0.

RESULTS

108 patients were included. Median follow-up was 6.3 years. The 5- and 10-year actuarial survival outcomes were as follows: FFbF, 63.1% and 52.0%; PCaSS, 90.5% and 77.8%; OS, 80.9% and 56.7%. On multivariate modeling, increasing grade group (HR 1.41, 95% CI 1.02-1.95, p = 0.036) and initial PSA at diagnosis (HR 1.02, 95% CI 1.004-1.05, p = 0.022) were associated with worse FFbF. Grade 3 toxicity occurred in 16.7% of patients; including genitourinary events in 15.7% and gastrointestinal events in 2.8% of patients. IPSS scores increased following implant, peaking at 2 months (median IPSS 20, p = 0.002) and thereafter remaining elevated throughout follow-up.

CONCLUSIONS

Salvage LDR brachytherapy is safe and efficacious, with acceptable grade 3+ toxicity and good biochemical control on long-term follow-up. Patients with higher grade group and higher PSA at initial diagnosis may be at increased risk for biochemical failure.