Residual prostate cancer in patients treated with endocrine therapy with or without radical radiotherapy: a side study of the SPCG-7 randomized trial

Is there a role for radical prostatectomy in the management of oligometastatic prostate cancer? A systematic review

CONTEXT

There is a growing interest about the role of radical prostatectomy (RP) in local cancer control in oligometastatic prostate cancer (PCa).

PURPOSE

To evaluate the oncological and functional outcomes of RP in the management of oligometastatic PCa through a systematic review.

METHODS

A systematic review search was performed and the following bibliographic databases were accessed: PubMed, Scopus, Embase and the Cochrane central register of controlled trials were searched from January 2000 to November 2022. This was carried out by the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines.

RESULTS

Based on the literature search of 384 articles, 11 (511 patients) met the inclusion criteria (mean age: 65.5 yr.). Positive surgical margins were 59%. Median follow-up ranged from 13 to 64 months. Clinical progression-free survival ranged from 56% at 3 years to 45% at 7 years. Specific and overall survival rates ranged from 60 to 80.5% and 78 to 80% at 5 years, respectively. Clavien ≥3 complications ranged from 0 to 21%. The urinary incontinence rate was 14.5%.

CONCLUSIONS

Similar to published studies, RP of oligometastatic PCa appears to be safe with acceptable morbidity in selected patients. The lack of a consensual definition, the low level of evidence and the bias of the comparative and retrospective studies available do not allow practical recommendations to be made. There is currently no place for metastatic surgery outside of participation in a clinical trial.

A Review on the Current Treatment Paradigm in High-Risk Prostate Cancer

High-risk prostate cancer is traditionally treated with a combination of radiotherapy (RT) and androgen deprivation therapy (ADT). However, recent advancements in systemic treatment and radiotherapy have widened the spectrum of treatment for this patient population. Use of image guidance and intensity modulation, as well as the incorporation of brachytherapy, has led to safe radiotherapy dose escalation with reduced risk of recurrence. Clinical trials have helped define the role of pelvic nodal radiotherapy, the role of stereotactic ablative radiotherapy, and the optimal duration and sequencing of ADT in combination with radiotherapy. Emerging evidence has redefined the role of surgery in this cohort. Contemporary clinical trials have identified new systemic therapy options in high-risk prostate cancer. Finally, new imaging modalities including multi-parametric MRI and molecular imaging and genomic classifiers have ushered a new era in patient selection, risk stratification, and treatment tailoring.

Long-term biopsy outcomes in prostate cancer patients treated with external beam radiotherapy: a systematic review and meta-analysis

BACKGROUND

Biopsy after external beam radiotherapy (EBRT) for localised prostate cancer (PCa) is an infrequently used but potentially valuable technique to evaluate local recurrence and predict long-term outcomes.

METHODS

We performed a meta-analysis of studies until March 2020 where a post-EBRT biopsy was performed on patients with low-to intermediate risk PCa, according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. The primary outcome was the aggregate post-EBRT positive biopsy rate (≥2 years after EBRT) and the associated odds ratio (OR) of a positive biopsy on biochemical failure (BCF), distant metastasis-free survival (DMFS) and prostate cancer-specific mortality (PCSM). A sensitivity analysis was performed which examined biopsy rate as a function of post-EBRT biopsy protocol, PCa risk, ADT usage and radiation dose.

RESULTS

A total of 22 studies were included, of which 10 were randomised controlled trials and 12 were cohort studies. Nine out of the 22 studies used dosing regimens consistent with the 2020 NCCN radiotherapy guidelines. The weighted-average positive biopsy rate across all 22 studies was 32% (95%-CI: 25-39%, n = 3017). In studies where post-treatment biopsy was part of the study protocol, the rate was 35% (95%-CI: 21-38%, n = 2450). In the subgroup of studies that conformed to the 2020 NCCN radiotherapy guidelines, this rate was 22% (95% CI: 19-41%, n = 832). Patients with positive biopsy had a 10-fold higher odds of developing BCF (OR of 10.3, 95%-CI: 3.7-28.7, p < 0.00001), 3-fold higher odds of developing distant metastasis (OR 3.1, 95%-CI: 2.1-4.7, p < 0.00001) and 5-fold higher odds of dying from their PCa (OR 5.1, 95%-CI: 2.6-10, p < 0.00001).

CONCLUSION

A positive biopsy after EBRT is associated with a poor prognosis compared to a negative biopsy. The post-EBRT positive biopsy rate is an important measure which provides additional insight when comparing EBRT to other treatment modalities for PCa.

Ten-Year Results From a Phase II Study on Image Guided, Intensity Modulated Radiation Therapy With Simultaneous Integrated Boost in High-Risk Prostate Cancer

Purpose

There is no consensus on how to treat high-risk prostate cancer, and long-term results from hypofractionated radiation therapy are lacking. We report 10-year results after image guided, intensity modulated radiation therapy with hypofractionated simultaneous integrated boost and elective pelvic field.

Methods and Materials

Between 2007 and 2009, 97 consecutive patients with high-risk prostate cancer were included, treated with 2.7 to 2.0 Gy × 25 Gy to the prostate, seminal vesicles, and elective pelvic field. Toxicity was scored according to Radiation Therapy Oncology Group criteria and biochemical disease-free survival (BFS) defined by the Phoenix definition. Patients were subsequently divided into 3 groups: high risk (HR; n = 32), very high risk (VHR; n = 50), and N+/s–prostate-specific antigen (PSA) ≥100 (n = 15). Differences in outcomes were examined using Kaplan-Meier analyses.

Results

BFS in the patients at HR and VHR was 64%, metastasis-free survival 80%, prostate cancer-specific survival 90%, and overall survival (OS) 72%. VHR versus HR subgroups demonstrated significantly different BFS, 54% versus 79% (P = .01). Metastasis-free survival and prostate cancer-specific survival in the VHR group versus HR group were 76% versus 87% (P = .108) and 74% versus 100% (P = .157). Patients reaching nadir PSA <0.1 (n = 80) had significantly better outcomes than the rest (n = 17), with BFS 70% versus 7% (P < .001). Acute grade 2 gastrointestinal tract (GI) and genitourinary tract (GU) toxicity occurred in 27% and 40%, grade 3 GI and GU toxicity in 1% and 3%. Late GI and GU grade 2 toxicity occurred in 1% and 8%.

Conclusions

High-risk prostate cancer patients obtained favorable 10-year outcomes with low toxicity. There were significantly better results in the HR versus the VHR group, both better than the N+/PSA ≥100 group. A nadir PSA value < 0.1 predicted good prognosis.

Positive prostate biopsy following radiotherapy can predict metastasis-free survival in localized prostate cancer

Background/aims

To determine the impact of post-treatment biopsy results on 10-year metastasis-free survival (MFS), overall survival (OS) and cause-specific survival (CSS) in localized prostate cancer (PCa) patients treated with high-dose radiotherapy (RT).

Materials/Methods

Retrospective analysis of 232 patients with T1c-T3bN0M0 PCa who underwent a prostate biopsy 24-36 months after high-dose RT. Biopsies were categorized as positive biopsy (PB) if H&E staining showed evidence of residual malignancy and negative biopsy (NB) if no malignant cells were present. Kaplan-Meier estimates of 10-year MFS, OS and CSS rates were calculated for each group and Cox proportional-hazards models were used to estimate the hazard ratios. The median follow-up was 124 months (range 26-267).

Results

Sixty-two of 232 (26.7%) patients had post-treatment positive biopsies (PB). A positive post-treatment biopsy was significantly associated with a lower 10-year MFS (78.4% vs. 95.4%, p = 0.001, HR: 3.9, 95% CI: 1.8-8.3). Although patients with PB had worse outcomes that those with NB, we could not show a statistically significant difference in OS (81.0% vs. 87.9%, p = 0.282, HR: 1.3, 95% CI: 0.7-2.3) or CSS (96.2% vs. 99.4% (p = 0.201, HR. 2.4, 95% CI: 0.6-9.7). After multivariate analysis, the strongest predictor of MFS was the post-treatment biopsy status (p < 0.001, HR: 5.4, 95% CI 2.26-12.85) followed by Gleason score (p = 0.002, HR: 2.24, 95% CI 1.33-3.79).

Conclusion

A positive biopsy following RT can predict MFS in localized prostate cancer. These data highlight the relevance of achieving a local control and support the use of aggressive local therapeutic interventions for PCa.

SPCG-15: a prospective randomized study comparing primary radical prostatectomy and primary radiotherapy plus androgen deprivation therapy for locally advanced prostate cancer

OBJECTIVE

To describe study design and procedures for a prospective randomized trial investigating whether radical prostatectomy (RP) ± radiation improves cause-specific survival in comparison with primary radiation treatment (RT) and androgen deprivation treatment (ADT) in patients with locally advanced prostate cancer (LAPC).

MATERIALS AND METHODS

SPCG-15 is a prospective, multi-centre, open randomized phase III trial. Patients are randomized to either standard (RT + ADT) or experimental (RP with extended pelvic lymph-node dissection and with addition of adjuvant or salvage RT and/or ADT if deemed necessary) treatment. Each centre follows guidelines regarding the timing and dosing of postoperative RT and adjuvant treatment such as ADT The primary endpoint is cause-specific survival. Secondary endpoints include metastasis-free and overall survival, quality-of-life, functional outcomes and health-services requirements. Each subject will be followed up for a minimum of 10 years.

RESULTS

Twenty-three centres in Denmark, Finland, Norway and Sweden, well established in performing RP and RT for prostate cancer participated. Each country's sites were coordinated by national coordinating investigators and sub-investigators for urology and oncology. Almost 400 men have been randomized of the stipulated 1200, with an increasing rate of accrual.

CONCLUSIONS

The SPCG-15 trial aims to compare the two curatively intended techniques supplying new knowledge to support future decisions in treatment strategies for patients with LAPC The Scandinavian healthcare context is well suited for performing multi-centre long-term prospective randomized clinical trials. Similar care protocols and a history of entirely tax-funded healthcare facilitate joint trials.

Cytoreductive prostate radiotherapy in oligometastatic prostate cancer: a single centre analysis of toxicity and clinical outcome

Objectives

The current standard of care for patients with metastatic prostate cancer (mPCa) at diagnosis is androgen deprivation therapy (ADT) with or without anti-androgen and chemotherapy. The aim of this study was to define the role of a local radiotherapy (RT) treatment in the mPCa setting.

Methods

We retrospectively reviewed data of patients with PCa and bone oligometastases at diagnosis treated in our institution with ADT followed by cytoreductive prostate-RT with or without RT on metastases. Biochemical and clinical failure (BF, CF), overall survival (OS) and RT-toxicity were assessed.

Results

We identified 22 patients treated with ADT and external-beam RT on primary between June 2008 and March 2016. All of them but four were also treated for bone metastases. RT on primary with moderately and extremely hypofractionated regimes started after 10.3 months (3.9–51.7) from ADT. After a median follow-up of 26.4 months (10.3–55.5), 20 patients are alive. Twelve patients showed BF after a median time of 23 months (14.5–104) and CF after a median of 23.6 months (15.3–106.1) from the start of ADT. Three patients became castration resistant, starting a new therapy; median time to castration resistance was 31.03 months (range: 29.9–31.5 months). According to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC), only one patient developed acute grade 3 genitourinary toxicity. No late grade >2 adverse events were observed.

Conclusion

Prostate RT in oligometastatic patients is safe and offers long-lasting local control. When compared to ADT alone, RT on primary seems to improve biochemical control and long-term survival; however, this hypothesis should be investigated in prospective studies. Further research is warranted.

Cytoreductive radical prostatectomy in metastatic prostate cancer: Does it really make sense?

PURPOSE

Surgical removal of the primary tumor in metastatic prostate cancer (mPCa) is becoming a hotly debated issue. The purpose of this review was to summarize the current knowledge on cytoreductive radical prostatectomy (cRP) in this setting.

MATERIALS AND METHODS

We performed a non-systematic Medline/PubMed literature search of articles published in the field between January 2000 and April 2015.

RESULTS

Cytoreductive surgery has demonstrated its benefit in various malignancies with a solid biological rationale to justify its assessment in mPCa. cRP appears as a safe and feasible procedure in expert hands and well-selected patients. A growing body of evidence suggests a survival benefit for patients undergoing cRP as a part of a multimodal approach compared to those treated with systemic treatment alone. Nevertheless, little is known about the best clinical and tumor characteristics for the selection of patients most likely to benefit from cRP. The current literature is based on retrospective studies with small cohorts and limited follow-up or large uncontrolled population-based studies.

CONCLUSIONS

Data from various other malignancies together with the biological rationale and preliminary results in PCa suggest that cytoreductive surgery may be an option in some mPCa patients. The lack of randomized controlled trials and the low level of evidence in the current literature preclude any firms conclusion on the benefit of cRP in mPCa. Ongoing phase II and future phase III studies are mandatory to define the exact role of cRP in mPCa and to identify the patients who are most likely to benefit from cRP.

Stereotactic body radiation therapy (SBRT) delays the emergence of castration resistance in patients with oligometastatic prostate cancer

PURPOSE

To investigate whether bon e metastases-directed stereotactic body radiation therapy (SBRT) delays the emergence of castration resistance in patients with oligometastatic prostate cancer (OPC).

METHODS AND MATERIAL

OPC is usually managed with androgen deprivation therapy (ADT). Migration to castration-resistant prostate cancer will inevitably occur in the majority of these patients. There are several strategies aimed to delay the emergence of castration resistance including intermittent ADT, second generation antiandrogens (abiraterone, enzalutamide) or metastases-directed SBRT. The present report describes two cases of patients with OPC that received SBRT 24 Gy/3Rx to the solitary bony lesion after ADT failure.

RESULTS

Both cases showed complete and durable biochemical response for 13 and 17 months, respectively.

CONCLUSIONS

SBRT can be used to delay the emergence of castration resistance and the need for systemic therapy when used after ADT failure.

A comprehensive review of contemporary role of local treatment of the primary tumor and/or the metastases in metastatic prostate cancer

To provide an overview of the currently available literature regarding local control of primary tumor and oligometastases in metastatic prostate cancer and salvage lymph node dissection of clinical lymph node relapse after curative treatment of prostate cancer. Evidence Acquisition. A systematic literature search was conducted in 2014 to identify abstracts, original articles, review articles, research articles, and editorials relevant to the local control in metastatic prostate cancer. Evidence Synthesis. Local control of primary tumor in metastatic prostate cancer remains experimental with low level of evidence. The concept is supported by a growing body of genetic and molecular research as well as analogy with other cancers. There is only one retrospective observational population based study showing prolonged survival. To eradicate oligometastases, several options exist with excellent local control rates. Stereotactic body radiotherapy is safe, well tolerated, and efficacious treatment for lymph node and bone lesions. Both biochemical and clinical progression are slowed down with a median time to initiate ADT of 2 years. Salvage lymph node dissection is feasible in patients with clinical lymph node relapse after local curable treatment. Conclusion. Despite encouraging oncologic midterm results, a complete cure remains elusive in metastatic prostate cancer patients. Further advances in imaging are crucial in order to rapidly evolve beyond the proof of concept.

Rationale for stereotactic body radiation therapy in treating patients with oligometastatic hormone-naïve prostate cancer

Despite advances in treatment for metastatic prostate cancer, patients eventually progress to castrate-resistant disease and ultimately succumb to their cancer. Androgen deprivation therapy (ADT) is the standard treatment for metastatic prostate cancer and has been shown to improve median time to progression and median survival time. Research suggests that castrate-resistant clones may be present early in the disease process prior to the initiation of ADT. These clones are not susceptible to ADT and may even flourish when androgen-responsive clones are depleted. Stereotactic body radiation therapy (SBRT) is a safe and efficacious method of treating clinically localized prostate cancer and metastases. In patients with a limited number of metastatic sites, SBRT may have a role in eliminating castrate-resistant clones and possibly delaying progression to castrate-resistant disease.

Disseminated tumor cells and their prognostic significance in nonmetastatic prostate cancer patients

Detection of pretreatment disseminated cells (pre-DTC) reflecting its homing to bone marrow (BM) in prostate cancer (PCa) might improve the current model to predict recurrence or survival in men with nonmetastatic disease despite of primary treatment. Thereby, pre-DTC may serve as an early prognostic biomarker. Post-treatment DTCs (post-DTC) finding may supply the clinician with additional predictive information about the possible course of PCa. To assess the prognostic impact of DTCs in BM aspirates sampled before initiation of primary therapy (pre-DTC) and at least 2 years after (post-DTC) to established prognostic factors and survival in patients with PCa. Available BM of 129 long-term follow-up patients with T1-3N0M0 PCa was assessed in addition to 100 BM of those in whom a pretreatment BM was sampled. Patients received either combined therapy [n = 81 (63%)], radiotherapy (RT) with different duration of hormone treatment (HT) or monotherapy with RT or HT alone [n = 48 (37%)] adapted to the criteria of the SPCG-7 trial. Mononuclear cells were deposited on slides according to the cytospin methodology and DTCs were identified by immunocytochemistry using the pancytokeratin antibodies AE1/AE3. The median age of men at diagnosis was 64.5 years (range 49.5-73.4 years). The median long-term follow-up from first BM sampling to last observation was 11 years. Categorized clinically relevant factors in PCa showed only pre-DTC status as the statistically independent parameter for survival in the multivariate analysis. Pre-DTCs homing to BM are significantly associated with clinically relevant outcome independent to the patient's treatment at diagnosis with nonmetastatic PCa.

Side-effects of post-treatment biopsies in prostate cancer patients treated with endocrine therapy alone or combined with radical radiotherapy in the Scandinavian Prostate Cancer Group-7 randomized trial

OBJECTIVE

Post-treatment prostate biopsy side-effects were evaluated in patients with locally advanced prostate cancer on endocrine therapy alone or combined with radiotherapy in the Scandinavian Prostate Cancer Group-7 randomized trial.

MATERIAL AND METHODS

One-hundred and twenty patients underwent transrectalultrasound-guided biopsy, and were requested to complete a questionnaire on side-effects occurring within 7 days' follow-up.

RESULTS

The questionnaire was returned by 109 patients (91%) (endocrine therapy only 52%, combined endocrine therapy and radiotherapy 48%). Previous therapy had no significant influence on pain, urinary flow, haematuria or haematospermia. Pain at biopsy was reported in 63% (mild, 57%; moderate, 5.6%; severe, one patient) and pain at follow-up in 31% (mild, 27%; moderate, four patients). Haematuria (mean duration 2.2 days) was reported in 41%, and reduced urinary flow in 20% (mild, 18%; severe: four patients; no patient had urinary retention). Haematospermia was scarce. No patient reported urinary tract infection. Rectal bleeding occurred in 18% in the endocrine and 35% in the combined therapy group (p = 0.047), with a mean duration of 1.6 and 2.2 days, respectively (p = 0.031). In logistic regression analysis, a trend towards increased rectal bleeding was found in patients on combined endocrine therapy and radiotherapy (odds ratio 2.4, p = 0.050).

CONCLUSION

Patient-reported post-treatment prostate biopsy side-effects were mild and self-limiting.

[Node-positive prostate cancer. Value of radical prostatectomy]

The current review article critically discusses the potential advantages and disadvantages of radical prostatectomy in patients with locally advanced lymph node-positive prostate cancer. It is the purpose of the manuscript to develop a therapeutic algorithm for management of these patients to achieve optimal oncological and functional results. Based on the data in the literature radical prostatectomy as part of a multimodality approach seems to be indicated in the following clinical scenario: limited intrapelvic lymph node metastasis without bulky disease; complete resectability of the primary cancer and metastases by extended radical prostatectomy and extended pelvic lymphadenectomy; inclusion of the patient in a multimodality approach; life expectancy > 10 years. In patients with extensive locally advanced PCA or large pelvic metastases, radical prostatectomy might be indicated to improve local cancer control and to prevent significant local and supravesical complications. In these cases, the indication for extensive surgery includes radical cystoprostatectomy and should be discussed in an interdisciplinary tumour board.