The cytoreductive prostatectomy in metastatic prostate cancer: what the individual trials are hoping to answer

Current evidence on local therapy in oligometastatic prostate cancer

PURPOSE OF REVIEW

Metastatic prostate cancer (PCa) continues to be an invariably fatal condition. While historically, de-novo metastatic PCa was primarily treated with androgen deprivation therapy (ADT) and systemic therapy, there is a growing trend toward incorporating local treatments in the early management of the disease. This is particularly applicable to men with oligometastatic PCa (OMPC), which represents an 'intermediate phase' between localized and disseminated metastatic disease. Local treatment offers an opportunity for disease control before it progresses to a more advanced stage. This review discussed the current evidence for local treatment options for OMPC.

RECENT FINDINGS

Currently, it has been suggested that men with OMPC may have a more indolent course and, therefore, favorable outcomes may be observed with metastasis-directed therapy (MDT). This review will not address the role of MDT to patients with OMPC but will focus on local treatments of the primary disease. The three main forms of local therapy employed for OMPC are cryotherapy, radiation therapy, and cytoreductive prostatectomy (CRP). Whole gland cryotherapy, either with ADT or with ADT and systemic chemotherapy, has shown some limited promising results. Radiation therapy combined with ADT has also demonstrated improvements in progression-free survival in clinical trials (primarily STAMPEDE Arm G and HORRAD). CRP often combined with ADT has emerged as a potential strategy for managing OMPC, with promising findings primarily from retrospective studies. Currently, several randomized controlled trials are underway to further investigate the role of CRP in the oligometastatic setting.

SUMMARY

OMPC has become a unique category of disease with specific therapeutic implications. Lack of robust clinical data renders treatment selection controversial. Further studies with long follow up are necessary to identify men with oligometastatic disease who will benefit from local treatment.

A systematic review of cytoreductive prostatectomy outcomes and complications in oligometastatic disease

Objective

To analyze outcomes and complications of cytoreductive prostatectomy (CRP) for oligometastatic prostate cancer (PCa) in order to elucidate its role in this space.

Methods

We performed a systematic literature search using three databases (Medline, Scopus, and Web of Science). The primary endpoints were oncologic outcomes. The secondary endpoints were complication rates and functional results.

Results

In all studies, overall survival was better or at least comparable variable in the groups with CRP compared to no local treatment. The greatest benefit from CRP in 5-year overall survival in one study was 67.4% for CRP versus 22.5% for no local treatment. Cancer-specific survival (CSS) showed the same trend. Several authors found significant benefits from CSS in the CRP group: from 79% vs. 46% to 100% vs. 61%. CRP was a predictor of better CSS (hazard ratio 0.264, p=0.004). Positive surgical margin rates differed widely from 28.6% to 100.0%. Urinary continence in CRP versus RP for localized PCa was significantly lower (57.4% vs. 90.8%, p<0.0001). Severe incontinence occurred seldom (2.5%-18.6%). Total complication rates after CRP differed widely, from 7.0% to 43.6%. Rates of grades 1 and 2 events prevailed. Patients on ADT alone also showed a considerable number of complications varying from 5.9% to 57.7%.

Conclusion

CRP improves medium-term cancer control in patients with oligometastatic PCa. The morbidity and complication rates of this surgery are comparable with other approaches, but postoperative incontinence rate is higher compared with RP for localized disease.

Impact of PSMA PET on Prostate Cancer Management

OPINION STATEMENT

PSMA-PET has been a practice-changing imaging biomarker for the management of men with PCa. Research suggests improved accuracy over conventional imaging and other PET radiotracers in many contexts. With multiple approved PSMA-targeting radiotracers, PSMA PET will become even more available in clinical practice. Its increased use requires an understanding of the prospective data available and caution when extrapolating from prior trial data that utilized other imaging modalities. Future trials leveraging PSMA PET for treatment optimization and management decision-making will ultimately drive its clinical utility.

Progress in Oligometastatic Prostate Cancer: Emerging Imaging Innovations and Therapeutic Approaches

Prostate cancer (PCa) exhibits a spectrum of heterogeneity, from indolent to highly aggressive forms, with approximately 10-20% of patients experiencing metastatic PCa. Oligometastatic PCa, characterized by a limited number of metastatic lesions in specific anatomical locations, has gained attention due to advanced imaging modalities. Although patients with metastatic PCa typically receive systemic therapy, personalized treatment approaches for oligometastatic PCa are emerging, including surgical and radiotherapeutic interventions. This comprehensive review explores the latest developments in the field of oligometastatic PCa, including its biological mechanisms, advanced imaging techniques, and relevant clinical studies. Oligometastatic PCa is distinct from widespread metastases and presents challenges in patient classification. Imaging plays a crucial role in identifying and characterizing oligometastatic lesions, with new techniques such as prostate-specific membrane antigen positron emission tomography demonstrating a remarkable efficacy. The management strategies encompass cytoreductive surgery, radiotherapy targeting the primary tumor, and metastasis-directed therapy for recurrent lesions. Ongoing clinical trials are evaluating the effectiveness of these approaches. Oligometastatic PCa occupies a unique position between locally advanced and high-volume metastatic diseases. While a universally accepted definition and standardized diagnostic criteria are still evolving, emerging imaging technologies and therapeutic strategies hold promise for improving the patient outcomes in this intermediate stage of PCa.

Local Therapeutics for the Treatment of Oligo Metastatic Prostate Cancer

PURPOSE OF REVIEW

Metastatic prostate cancer remains universally lethal. Although de-novo metastatic prostate cancer was historically managed with systemic therapy alone, local therapies are increasingly utilized in the early treatment of the disease, particularly in patients with oligometastatic prostate cancer (OMPC). OMPC represents an intermediate stage between clinically localized and widespread metastatic disease. Diseases classified within this stage present an opportunity for localized targeting of the disease prior to progression to widespread metastases. The purpose of this review is to discuss the contemporary and emerging local therapies for the treatment of OMPC.

RECENT FINDINGS

To date, there are three utilized forms of local therapy for OMPC: cryoablation, radiation therapy, and cytoreductive prostatectomy. Cryoablation can be utilized for the total ablation of the prostate and has shown promising results in patients with OMPC either in combination with ADT or with ADT and systemic chemotherapy. Radiation therapy along with ADT has demonstrated improvement in progression-free survival. The STAMPEDE Arm G, PEACE-1, and the HORRAD clinical trials have investigated radiation therapy for mPCa compared to standard of care versus systemic therapy with varying results. Cytoreductive radical prostatectomy (CRP) in conjunction with ADT has also been proposed in the management of OPMC with promising results from case-control and retrospective studies. Currently there are larger controlled trials investigating CRP for OPMC including the SIMCAP, LoMP, TRoMbone, SWOG 1802, IP2-ATLANTA, g-RAMPP, and FUSCC-OMPCa trials. Given the novel nature of local treatments for OPMC, treatment selection is still controversial and requires long-term follow-up and randomized clinical trials to aid patient and clinician decision making.

Personalizing approaches to the management of metastatic hormone sensitive prostate cancer: role of advanced imaging, genetics and therapeutics

PURPOSE

To summarize contemporary and emerging strategies for the diagnosis and management of metastatic hormone sensitive prostate cancer (mHSPC), focusing on diagnostic testing and therapeutics.

METHODS

Literature review using PUBMED-Medline databases as well as clinicaltrials.gov to include reported or ongoing clinical trials on treatment for mHSPC. We prioritized the findings from phase III randomized clinical trials, systematic reviews, meta-analyses and clinical practice guidelines.

RESULTS

There have been significant changes to the diagnosis and staging evaluation of mHSPC with the integration of increasingly accurate positron emission tomography (PET) imaging tracers that exceed the performance of conventional computerized tomography (CT) and bone scan. Germline multigene testing is recommended for the evaluation of patients newly diagnosed with mHSPC given the prevalence of actionable alterations that may create candidacy for specific therapies. Although androgen deprivation therapy (ADT) remains the backbone of treatment for mHSPC, approaches to first-line treatment include the integration of multiple agents including androgen receptor synthesis inhibitors (ARSI; abiraterone) Androgen Receptor antagonists (enzalutamide, darolutamide, apalautamide), and docetaxel chemotherapy. The combination of ADT, ARSI, and docetaxel chemotherapy has recently been evaluated in a randomized trial and was associated with significantly improved overall survival including in patients with a high burden of disease. The role of local treatment to the prostate with radiation has been evaluated in randomized trials with additional studies underway evaluating the role of cytoreductive radical prostatectomy.

CONCLUSION

The staging and initial management of patients with mHSPC has undergone significant advances in the last decade with advancements in the diagnosis, treatment and sequencing of therapies.

The role of cytoreductive radical prostatectomy and lymph node dissection in bone-metastatic prostate cancer: A population-based study

BACKGROUNDS

The role of cytoreductive radical prostatectomy (cRP) for bone-metastatic prostate cancer (bmPCa) remains controversial. We aimed to figure out whether cRP and lymph node dissection (LND) can benefit bmPCa.

METHODS

11,271 PCa patients with bone metastatic burden from 2010 to 2019 were identified using SEER-Medicare. Overall survival (OS) and cancer-specific survival (CSS) rates were visualized using Kaplan-Meier plots. Multivariable Cox regression analyses were constructed to examine the effects of cRP and LND on survival, after stratifying to age, prostate specific antigen (PSA), clinical stages, Gleason score, metastatic burden, radiotherapy, and chemotherapy status.

RESULTS

317 PCa patients underwent cRP and cRP was increasingly performed for bmPCa from 2010 (2.2%) to 2019 (3.0%) (p < 0.05). In multi analyses, cRP was predisposed to a better OS or CSS in patients with age < 75, PSA < 98 ng/mL, bone-only metastatic sites or patients not receiving chemotherapy (all p < 0.05). For the patients undergoing cRP, LND especially extended LND was associated with a better OS or CSS (all p < 0.05).

CONCLUSIONS

cRP might benefit OS or CSS in young patients with low PSA and bone-only metastatic sites not receiving chemotherapy. And a clear OS or CSS benefit of LND especially extended LND was observed in patients undergoing cRP.

Current treatment patterns within 1 year after prostate cancer diagnosis in Korean patients over 75 years old: a retrospective multicenter study

Background

We aimed to evaluate the current status of first-line treatment options for prostate cancer in patients aged ≥75 years in Korea.

Materials and methods

The study included 873 patients diagnosed with biopsy-proven prostate cancer at 5 institutions in Korea from January 2009 to December 2018. Inclusion criteria were aged ≥75 years at diagnosis, prostate biopsy with ≥12 cores, and follow-up period ≥1 year. Clinical data were retrospectively collected from electronic medical records.

Results

Primary treatment for prostate cancer in patients aged ≥75 years included androgen deprivation therapy (ADT) (n = 614), radical prostatectomy (RP) (n = 114), and radiation therapy (n = 62). Among patients with RP, nine patients received ADT before RP. The RP group was younger with better Eastern Cooperative Oncology Group Performance Status (ECOG PS), lower initial prostate-specific antigen (PSA), Gleason score (GS), max percent positive cores, less positive cores, and less advanced clinical Tumor Node Metastasis (TNM) stage compared with the ADT group. Multivariate analysis showed that age, ECOG PS, and PSA were independent prognostic factors for RP. When the ADT group was classified by therapeutic regimens, the most common therapeutic regimen was maximal androgen blockade (MAB) (n = 571), and leuprolide + bicalutamide (n = 330) was the most common MAB regimen. Multivariate analysis for secondary treatment showed that age, ECOG PS, GS, and clinical N1 or M1 stage were independent predictive factors. Enzalutamide was the most preferred treatment for tertiary treatment.

Conclusion

In patients with prostate cancer aged ≥75 years, the most common treatment option was MAB, and the leuprolide + bicalutamide was the most common MAB regimen. Age, ECOG PS, and PSA are the useful indicators of surgical treatment, which increased during the study period. Younger patients with high GS and advanced clinical stage were more likely to undergo secondary treatment.

A Review of Modern Imaging Landscape for Prostate Cancer: A Comprehensive Clinical Guide

The development of prostate cancer imaging is rapidly evolving, with many changes to the way patients are diagnosed, staged, and monitored for recurrence following treatment. New developments, including the potential role of imaging in screening and the combined diagnostic and therapeutic applications in the field of theranostics, are underway. In this paper, we aim to outline the current landscape in prostate cancer imaging and look to the future at the potential modalities and applications to come.

Development and validation of a novel risk model in newly diagnosed de novo bone metastatic prostate cancer (M1b): a retrospective study

Background

Previous studies suggested that bone metastasis has a significant effect on the time of progression to metastatic castration-resistant prostate cancer (CRPC) for newly diagnosed de novo bone metastatic hormone-sensitive prostate cancer (mHSPC). Nevertheless, the effect of different bone metastasis sites was not fully evaluated. This study aimed to develop and validate a novel bone metastatic risk model.

Methods

We enrolled 122 patients who were newly diagnosed with de novo bone metastatic prostate cancer following primary androgen deprivation based therapy at our institution from January 2008 to June 2021. The metastatic bone sites were classified into six sites: skull; cervical, thoracic, and lumbar vertebrae; chest (ribs and sternum); pelvis; upper limbs; and lower limbs. We calculated the bone metastatic score (BMS) for each site: 0 points were assigned for non-metastasis and 1 point was assigned for metastasis. The X-tile was adopted to acquire optimal cutoff points of BMS. We defined high-risk group (HRG) as BMS ≥ 3 and low-risk group (LRG) as BMS < 3. The new bone risk stratification was validated by calculating the area under the receiver operating characteristic curve (AUC). Subsequently, the relevant clinical prognostic variables were added to construct a predictive nomogram for predicting CRPC.

Results

The median patient age was 73 years. Most patients had Gleason score ≤8 (93 cases, 76.2%). The median follow-up duration was 11.5 months (range: 2-92 months). Eighty-six patients progressed to CRPC during the follow-up. The most common bone metastatic site was the pelvis (90.2%). The median BMS was 4. Seventy-six patients had HRG, while forty-six had LRG. The 1-, 2-, and 3-year AUCs for H/LRG were 0.620, 0.754, and 0.793, respectively. The HRG was associated with earlier time to CRPC. A nomogram based on four parameters (Gleason score, H/LRG, prostate-specific antigen [PSA] nadir, and time to PSA nadir) was developed to predict CRPC. Internal validation using bootstrapping demonstrated good accuracy for predicting the CRPC (C-index: 0.727). The calibration analysis demonstrated that the model performed well.

Conclusion

We established a novel H/LRG risk model for newly diagnosed de novo bone metastatic prostate cancer, which provided evidence to support clinical decision-making.

The current role of precision surgery in oligometastatic prostate cancer

Oligometastatic prostate cancer (omPCa) is a novel intermediate disease state characterized by a limited volume of metastatic cells and specific locations. Accurate staging is paramount to unmask oligometastatic disease, as provided by prostate-specific membrane antigen-positron emission tomography. Driven by the results of prospective trials employing conventional and/or modern staging modalities, the treatment landscape of omPCa has rapidly evolved over the last years. Several treatment-related questions comprising the concept of precision strikes are under development. For example, beyond systemic therapy, cohort studies have found that cytoreductive radical prostatectomy (CRP) can confer a survival benefit in select patients with omPCa. More importantly, CRP has been consistently shown to improve long-term local symptoms when the tumor progresses across disease states due to resistance to systemic therapies. Metastasis-directed treatments have also emerged as a promising treatment option due to the visibility of oligometastatic disease and new technologies as well as treatment strategies to target the novel PCa colonies. Whether metastases are present at primary cancer diagnosis or detected upon biochemical recurrence after treatment with curative intent, targeted yet decisive elimination of disseminated tumor cell hotspots is thought to improve survival outcomes. One such strategy is salvage lymph node dissection in oligorecurrent PCa which can alter the natural history of progressive PCa. In this review, we will highlight how refinements in modern staging modalities change the classification and treatment of (oligo-)metastatic PCa. Further, we will also discuss the current role and future directions of precision surgery in omPCa.

The clinical consequences of routine 68Ga-PSMA-11 PET/CT in patients with newly diagnosed prostate cancer, ISUP grade 5 and no metastases based on standard imaging - preliminary results

AIM

To evaluate the clinical consequences of prostate specific membrane antigen (PSMA) PET/CT for primary staging in patients with ISUP grade 5 (Gleason score ≥9) prostate cancer (PCa), and no definitive distant metastases based on standard imaging.

METHODS

At our tertial referral center, PSMA PET/CT became standard of care from August 2018 for primary staging of prostate cancer given the following criteria: (1) no prior treatment for prostate cancer, (2) ISUP grade 5, (3) no definitive metastases on standard imaging (contrast enhanced CT and bone scintigraphy), and (4) deemed suitable for treatment with curative intent based on comorbidity and life expectancy. We present the preliminary results of first six months recruitment with 12 months of follow-up.

RESULTS

Forty-eight patients (mean age 69 years, median PSA 13.0 ng/mL, 20 patients with locally advanced PCa) were included. CT was positive in pelvic lymph nodes in two patients, bone scintigraphy was equivocal in three patients. PSMA PET/CT showed pathological uptake outside the prostatic bed in 22 patients (46%) of which 13 patients (27%) showed lesions confined to regional lymph nodes, and nine patients (19%) showed nonregional lymph node metastases and/or bone metastases. PSMA PET/CT changed the treatment strategy from curatively intended treatment to palliative treatment in 18 patients (38%).

CONCLUSION

PMSA PET/CT revealed pathological uptake in a large proportion of high-risk patients at primary staging among patients with no definite metastases on standard imaging leading to change of patient management in 38% of the patients.

Feasibility and safety of radical prostatectomy for oligo-metastatic prostate cancer: the Testing Radical prostatectomy in men with prostate cancer and oligo-Metastases to the bone (TRoMbone) trial

OBJECTIVES

To test the feasibility of randomisation to radical prostatectomy (RP) plus pelvic lymphadenectomy in addition to standard-of-care (SOC) systemic therapy in men with newly diagnosed oligo-metastatic prostate cancer.

PATIENTS AND METHODS

A prospective, randomised, non-blinded, feasibility clinical trial with an embedded QuinteT Recruitment Intervention (QRI) to optimise recruitment was conducted in nine nationwide tertiary care centres undertaking high-volume robotic surgery. We aimed to randomise 50 men with synchronous oligo-metastatic prostate cancer within an 18-month recruitment period to SOC systemic therapy vs SOC plus RP (intervention arm). The main outcome measures were: ability to randomise patients, optimised by a QRI; EuroQoL five Dimensions five Levels (EQ-5D-5L) questionnaires to capture quality-of-life (QoL) data at baseline and 3 months post-randomisation; routine clinicopathological assessment to capture adverse events and prostate-specific antigen in both arms, plus standard perioperative parameters in the surgical arm.

RESULTS

A total of 51 men were randomised within 14 months (one was subsequently deemed ineligible), with 60-83% accrual rate in centres that recruited at least two patients. All patients completed the trial follow-up; one patient in the intervention arm subsequently did not undergo the surgical intervention and one in the SOC arm refused all therapies. The QRI positively impacted recruitment. QoL data showed similarly high functioning in both study arms. Surgery for men with oligo-metastatic prostate cancer was found to be safe and had similar impact on early functional outcomes as surgery for standard indication.

CONCLUSION

It is feasible to randomise men with synchronous oligo-metastatic prostate cancer to a surgical intervention in addition to standard systemic therapies. While surgery appeared safe with no substantial impact on QoL in this feasibility study, a large randomised controlled trial is now warranted to examine treatment effectiveness of this additional component in the multimodality management of oligo-metastatic prostate cancer.

New Paradigms for Cytoreductive Nephrectomy

Simple Summary

Cytoreductive surgery (CS) is performed to remove the primary tumor in the setting of metastatic disease. In metastatic renal cell carcinoma (mRCC), the role of cytoreductive nephrectomy (CN) in the treatment paradigm has evolved, adjusting to new changes in systemic therapy agents. In particular, immunotherapeutic agents, which utilize the body’s own immune system to attack cancerous cells, have improved over the past decade. Newer immunotherapy agents offer more effective treatments in mRCC, with the goal of more tolerable side effect profiles. However, now urologic and medical oncologists must reframe the role of CN in the context of these new systemic therapies. This review will discuss the current data on this topic as well as the historical context in which it is being studied.

Abstract

The role of CN in the treatment of metastatic renal cell carcinoma (mRCC) has been studied over the course of the past few decades. With the advent of immuno-oncologic (IO) agents, there has been a paradigm shift in the treatment of RCC. Within this new era of cancer care, the role of CN is unclear. There are several studies currently underway that aim to assess the role of CN in combination with these therapies. We reviewed articles examining CN, both historically and in the modern immunotherapy era. While immune-oncologic agents are relatively new and large clinical trials have yet to be completed, data thus far is promising that CN may provide clinical benefit. Multiple ongoing trials may clarify the role of CN in this new era of cancer care.

Cytoreductive prostate cryoablation and metronomic cyclophosphamide for metastatic hormone-sensitive prostate cancer

Aim: This study reports the outcomes of cytoreductive prostate cryoablation and metronomic cyclophosphamide for the treatment of metastatic hormone-sensitive prostate cancer (mHSPC). Methods: Patients with mHSPC from the authors' prostate cancer database who had received cytoreductive prostate cryoablation and metronomic cyclophosphamide were identified retrospectively. Results: Eight consecutive patients were enrolled in the study. All the patients tolerated combination therapy. The median metastatic castration-resistant prostate cancer-free survival was 62.5 months. Seven patients (87.5%) had a prostate-specific antigen nadir <0.1 ng/ml. Dysuria and hematuria before prostate cryoablation disappeared within 1 month after cryosurgery, and no incontinence was seen after prostate cryoablation. No local therapy was needed during follow-up. Conclusion: Cytoreductive prostate cryoablation and metronomic cyclophosphamide prove an effective and safe combination therapy for mHSPC.

Genomic analysis and long-term outcomes of a phase 1 clinical trial on cytoreductive radical prostatectomy

Purpose

Approximately 7% of patients with newly diagnosed prostate cancer (PCa) in the US will have have metastatic disease. The dogma that there is no role for surgery in this population has been questioned recently. Here we report long-term outcomes of a phase 1 clinical trial on cytoreductive radical prostatectomy.

Materials and methods

This is a multicenter phase 1 trial. The major inclusion criterion was biopsy proven N1M0 or NxM1a/b PCa. Primary end point was the Clavien-Dindo-based major complication rate. Secondary outcomes were biochemical progression and overall survival. RNA-seq correlative study was conducted in nine select cases as a pilot study.

Results

Final accrual was 32 patients of which 25 and 7 were cNxM1 and cN1M0, respectively. With the median follow-up of 46 months (interquartile range 31.7 - 52.7 months), 25 out of the 32 patients (75%) were alive at the time of last contact. There were three disparate groups based on the oncologic outcome: favorable, intermediate, and poor. In seven men with favorable response, androgen deprivation therapy was switched to intermittent approach and five remain free of any evidence of disease after more than two years off all systemic therapy with the normalization of serum testosterone. Of these five patients, three had M1 disease. Long-term use of one pad or less per day was 80%. RNA-seq analysis revealed an enriched downregulation of tumor necrosis factor (TNF)-α signature in the favorable group.

Conclusion

Overall long-term oncologic outcome of cytoreductive radical prostatectomy was significantly higher than historical results. Importantly, the combination of surgery with systemic therapy may result in a long durable response in a minority of men who present with metastatic PCa.

[Treatment of primary oligometastatic prostate cancer]

BACKGROUND

Multimodal treatment concepts are gaining in importance in the treatment of prostate cancer patients with primary oligometastatic disease. Data from randomized studies show that survival advantages can be achieved in this patient collective by the combination of local and systemic treatment compared to systemic treatment alone.

OBJECTIVE

To analyze the available data on therapeutic approaches for oligometastatic prostate cancer.

MATERIAL AND METHODS

Summary and discussion of current studies on systemic and local treatment of de novo oligometastatic prostate cancer.

RESULTS

Systemic treatment continues to be the standard of care in the oligometastatic stage of prostate cancer. Furthermore, irradiation of the prostate is recommended for patients with a low metastasis burden after this led to an extension of the overall survival in a randomized phase III study. Large case series suggest that radical prostatectomy can also improve oncological endpoints. The results of prospective phase II studies on metachronous metastatic disease provide evidence that local ablative radiotherapy of individual metastases can improve progression-free survival; however, the value of this approach in de novo metastatic disease is just as unclear as that of a triple treatment combination consisting of local and extended systemic treatment.

CONCLUSION

In addition to systemic treatment, irradiation of the prostate is a new standard of care for the oligometastatic stage ("low tumour burden").

Marginal improvement in survival among patients diagnosed with metastatic prostate cancer in the second-line antiandrogen therapy era

Since 2004, multiple blockbuster drugs have been approved for men with metastatic prostate cancer. Nevertheless, it has been reported that no improvement in survival was observed between 2004 and 2009. Herein, we have analyzed the SEER database to assess the survival outcome of metastatic prostate cancer patients since 2000. The results demonstrated that there was an improvement in both overall and prostate cancer-specific survival for 4 months among men diagnosed with metastatic prostate cancer from 2010 to 2016 when compared to those in the pre-2010 period. Interestingly, this survival benefit was limited to patients with bone and visceral metastasis (M1b and M1c stages). Collectively, our observation suggests that despite the new treatment agents such as second-line antiandrogen therapies introduced in the modern era, the improvement in survival of metastatic prostate cancer patients has been surprisingly small.

Local Therapies in Oligometastatic and Oligoprogressive Prostate Cancer

Oligometastatic disease was originally defined by Hellman and Weichselbaum as an intermediate-state existing between locally confined and widely disseminated malignancy, whose natural history could be positively impacted with systemic and importantly local therapies such as radiation. Currently oligometastatic prostate cancer (OPCa) is defined clinically by lesion enumeration and several subgroups exist: de novo (synchronous) oligometastatic disease present at initial diagnosis, oligorecurrent (metachronous) disease arising after definitive therapy to the prostate, and oligoprogressive disease where isolated lesions progress in a background of otherwise stable disease. In this review we highlight current knowledge and the potential future of local therapies, such as radiation to the primary prostate and metastasis-directed therapy (MDT), in the disease management of OPCa for all 3 subgroups. In addition, we examine more recent studies classifying the patterns of failure and natural history of OPCa following treatment with local therapies. Finally, while current clinical definitions of OPCa dominate, we introduce studies attempting to elucidate a more biological definition of OPCa to allow for improved selection of patients to treat with local therapies and to better inform precision combination approaches with systemic therapy.

The Role of Cytoreductive Radical Prostatectomy in the Treatment of Newly Diagnosed Low-volume Metastatic Prostate Cancer. Results from the Local Treatment of Metastatic Prostate Cancer (LoMP) Registry

Background

Radiotherapy to the prostate (RTp) prolongs survival for patients with low-volume, newly diagnosed metastatic prostate cancer (ndmPC).

Objective

to evaluate whether cytoreductive radical prostatectomy (cRP) is equally beneficial as RTp in low-volume ndmPC.

Design, setting, and participants

A multicenter prospective registry was established in 2014 to observe patients with ndmPC. Eligible patients were offered cRP or RTp. For this study we selected only patients with low-volume ndmPC (n = 109). Of these, 48, 26, and 35 patients underwent cRP, RTp, and no local therapy (NLT), respectively. Median follow-up was 32 mo (interquartile range 16–49).

Intervention

cRP was compared with RTp and NLT.

Outcome measurements and statistical analysis

Overall survival (OS), cancer-specific survival (CSS), and local event–free survival (LEFS) were calculated using the Kaplan-Meier method. Factors prognostic for OS were identified using univariate and multivariate Cox regression analysis.

Results and limitations

The 2-yr OS was 93%, 100%, and 69%, and 2-yr CSS was 93%, 100%, and 75% for cRP, RTp, and NLT, respectively. The cRP and RTp groups had better OS compared to NLT and there was no significant difference between cRP and RTp. The 2-yr LEFS was 92%, 77%, and 60% for cRP, RTp, and NLT, respectively. The cRP group had better LEFS compared to RTp and NLT, and there was no significant difference between RTp and NLT. Advanced tumor stage, Eastern Cooperative Oncology Group performance status ≥2, and NLT were negative prognostic factors for OS. The main limitation is selection of fitter patients with less advanced tumors for cRP and the small sample size.

Conclusions

For selected patients with low-volume ndmPC, cRP is able to achieve similar OS and CSS to RTp. cRP is effective in preventing local events due to disease progression.

Patient summary

Patients with a low volume of newly diagnosed prostate cancer that has spread beyond the prostate gland might benefit from removal of the prostate, which we found was as effective as radiotherapy to the prostate in prolonging survival. Removal of the prostate is effective in preventing urinary problems caused by cancer progression.

Treatment Strategies for Metastatic Castration-Sensitive Prostate Cancer: From "All-Comers" to "Personalized" Approach

Standard treatment for metastatic castration-sensitive prostate cancer (mCSPC) was androgen-deprivation therapy (ADT) for >7 decades, and this was termed the “all-comers” approach. A remarkable evolution in the treatment of mCSPC has been noted in the previous several years. High-quality clinical trials have shown that the addition of docetaxel or androgen receptor pathway inhibitors, such as abiraterone acetate, enzalutamide, and apalutamide, to ADT improves the overall survival (OS) as compared to ADT alone. The first 2 trials demonstrated the benefits of docetaxel and abiraterone acetate in terms of OS in high-volume and high-risk cancer subgroups, respectively. The later trials indicated that upfront combination therapies were associated with improved OS in all patients, irrespective of tumor volume and risk category. Upfront combination therapies are becoming a standard of care for all patients with mCSPC. However, meta-analyses have failed to show that all upfront combination therapies provide significant survival benefits in all patient subgroups. In the low-volume subgroup, significance was observed only for treatment with enzalutamide and radiation to the prostate. Men with low-volume low-risk cancer who have favorable response to ADT achieve long-term survival with ADT only, and toxicities induced by combination therapies would exceed the benefit for these patients. Treatments should be tailored to each patient because mCSPC has marked diversity in its biological and clinical features. Recent advances in diagnostic and molecular technologies will provide useful prognostic and predictive biomarkers, and the treatment strategy will shift from the “for all-comers” to the “individualized” approach.

Efficacy and safety of Prostate stereotactic body radiotherapy for metastatic castration-resistant prostate cancer: A prospective cohort study

BACKGROUND

The efficacy and safety of prostate SBRT in men with mCRPC is unknown.

MATERIALS AND METHODS

A prospective cohort study was conducted with 125 men diagnosed with mCRPC. All patients received ADT plus chemotherapy. Patients were randomly assigned to receive daily prostate SBRT (36-48 Gy in 6-8 fractions). Patients who did not receive SBRT served as controls.

RESULTS

The primary endpoints were PFS and OS. After 89 months of total follow-up, the median PFS was 13.8 months in the SBRT group (n = 61) and 12.0 months in the control group (n = 64) (HR, 0.87; 95% CI, 0.61-1.24; P = 0.249). The OS was 25.7 months in the SBRT group and 23.8 months in the control group (HR, 0.93; 95% CI, 0.65-1.33; P = 0.230). A non-significant increase in the PSA response rate (50.8% vs. 43.7%) and time to PSA progression (8.3 months vs. 7.0 months) was observed in the SBRT group compared to the control group; however, the time to symptomatic progression was significantly prolonged in the SBRT group (11.3 months) compared to the control group (8.5 months) (HR, 0.76; 95% CI, 0.53-1.08; P = 0.019). There was an 11.5% incidence of radiation cystitis and radiation rectitis in the SBRT group, and the degree and incidence of hormone-related and chemotherapy-related adverse events were similar between the two groups.

CONCLUSION

Adding prostate SBRT significantly prolonged the time to symptomatic progression and non-significantly prolonged PFS and OS among men with mCRPC compared to treatment with ADT plus chemotherapy alone.

Pathologic nodal downstaging in men with clinically involved lymph nodes undergoing radical prostatectomy: Implications for definitive locoregional therapy

A prostate cancer (CaP) patient with nonmetastatic but clinical positive lymph nodes (cN+) represents a difficult clinical scenario. We compare overall survival (OS) between cN+ men that underwent radical prostatectomy (RP) and were found to have negative node status (pN) with those found to have positive nodal status (pN+), and assess predictors of discordant nodal status. We queried the National Cancer Data Base between 2004 and 2015 for patients that were cT1-3 cN+ cM0 CaP treated with RP. Patients with 0 nodes, cT4, or cM1 disease were excluded. We compared groups based on pathologic nodal status: Discordant (cN+ -> pN) & Concordant (cN+ -> pN+). Kaplan Meier estimations were used to compare OS. Logistic regression was used to determine possible predictors of nodal status. We find that of 6470 cN+ patients, 1,367 (21.1%) underwent RP, 866 (13.4%) had confirmed nodal status. Discordant status was found in 159 (18.4%) and concordant staging in 707 (81.6%). Differences exist in PSA at diagnosis (7.3 vs. 11.2), biopsy group, # of nodes examined (7 vs. 10), race, and Charlson index. Discordant staging had longer OS compared to Concordant staging (P = 0.007) and similar OS to a 3:1 matched cohort of high risk localized CaP patients used as reference (P = 0.46). Lower Gleason Score (GG1-3) was associated with an increased likelihood of discordant staging. Clinical nodal staging is associated with a substantial false positive rate. Discordant status had better OS than Concordant status and similar OS to matched patients with localized CaP. Clinical nodal staging may inappropriately lead to noncurative therapy in a substantial number of men with potentially curable disease.

Comparative Efficacy of Combined Radiotherapy, Systemic Therapy, and Androgen Deprivation Therapy for Metastatic Hormone-Sensitive Prostate Cancer: A Network Meta-Analysis and Systematic Review

Background: Recent randomized clinical trials have examined the efficacy of different combinations of systemic and local treatment approaches for metastatic hormone-sensitive prostate cancer (mHSPC). We compared the efficacy of these combined regimens in order to identify the optimal therapy for specific patient subgroups. Methods: The treatments were abiraterone (ABI), apalutamide (APA), docetaxel (DOC), enzalutamide (ENZ), and radiotherapy (RT) combined with androgen-deprivation therapy (ADT). Five electronic databases were searched up to May 7, 2020 for relevant trials. The risk of bias in the included trials was evaluated with the Cochrane tool. The hazard ratio (HR) with 95% confidence interval (CI) was determined for the included trials and indirect comparisons were performed using the R software. Results: In total, 10 randomized, controlled trials with 11,194 patients were included in the meta-analysis. ADT + RT was superior to ADT monotherapy in terms of overall survival (HR = 0.96, 95% CI: 0.85-1.1) and conferred a survival benefit in a subgroup of low-volume patients (HR = 0.68, 95% CI: 0.54-0.87). Combined systemic treatments were significantly superior to ADT monotherapy in comparisons of survival and prostate-specific antigen response, including in the high-volume subgroup; meanwhile, in the low-volume subgroup only ADT + ENZ (HR = 0.38, 95% CI 0.21-0.69) showed a significant clinical benefit. In the Gleason score <8 subgroup, all combined systemic treatments were superior to ADT monotherapy, but the results were only significant for ADT + APA (HR = 0.56, 95% CI: 0.33-0.95) and ADT + DOC (HR = 0.71, 95% CI: 0.54-0.92). In the Gleason score ≥8 subgroup, ADT monotherapy was inferior (albeit not significantly) to combined treatments. In a ranking of performed comparisons, ADT + ENZ was the optimal regimen, although this was non-significant. Combined therapies also demonstrated superiority in quality-of-life indicators such as time to skeletal events and pain progression. Conclusion: ADT + radiotherapy led to superior outcomes in mHSPC patients with low-volume disease. While all combined systemic regimens confer a survival advantage over ADT monotherapy, the optimal treatment approach for certain mHSPC patient subgroups remains to be determined.

A novel prognostic model for Japanese patients with newly diagnosed bone‐metastatic hormone‐naïve prostate cancer

Objectives

To evaluate the prognosis of newly diagnosed patients with metastatic hormone‐naïve prostate cancer (mHNPC) and develop a novel prognostic model based on ChemoHormonal Therapy Versus Androgen Ablation Randomized Trial for Extensive Disease in Prostate Cancer (CHAARTED) risk classifications.

Patients and methods

We retrospectively analyzed the data of 578 newly diagnosed mHNPC patients initially treated with androgen deprivation therapy. We evaluated three clinical factors, namely, CHAARTED risk classifications (high‐volume disease [HVD] vs low‐volume disease [LVD]), Gleason scores (GS, 9‐10 vs ≤8), and hemoglobin (Hb, ≤13.0 g/dL vs >13.0 g/dL), for their prognostic potential in predicting time to castration‐resistant prostate cancer (TTC) and overall survival (OS) of mHNPC patients by multivariate analysis. Moreover, we developed a novel prognostic model that consisted of significant prognostic factors.

Results

Of the entire cohort, the median TTC and OS values were 18.3 and 67.5 months, respectively. HVD, GS 9‐10, and Hb ≤13.0 g/dL were independent poor prognostic factors for both TTC and OS. We developed a novel prognostic model which could stratify mHNPC patients into four risk groups according to the numbers of poor prognostic factors: group 1, LVD with low‐risk (LVD patients without GS 9‐10 and Hb ≤13.0 g/dL); group 2, LVD with high‐risk (LVD patients with GS 9‐10, Hb ≤13.0 g/dL, or both); group 3, HVD with low‐risk (HVD patients without GS 9‐10 with or without Hb ≤13.0 g/dL); and group 4, HVD with high‐risk (HVD patients with GS 9‐10 with or without Hb ≤13.0 g/dL). The median TTC and OS of groups 1, 2, 3, and 4 were 124.8, 36.4, 17.9, and 11.2 months, and 117.2, 94.2, 67.9, and 46.2 months, respectively. A significant difference in TCC and OS was found between all groups.

Conclusion

We developed a prognostic model for mHNPC patients that consisted of CHAARTED risk classifications, GS, and Hb. Our prognostic model could significantly stratify the prognosis of patients with LVD and HVD into two groups each. This model might be a good reference for shared decision making between patients and physicians on the initial treatment for mHNPC.