Testosterone suppression plus enzalutamide versus testosterone suppression plus standard antiandrogen therapy for metastatic hormone-sensitive prostate cancer (ENZAMET): an international, open-label, randomised, phase 3 trial

B7-H3 and c-MET in advanced prostate cancer: exploring possibilities of novel bi-specific drug development

PURPOSE

Prostate cancer (PCa) is a serious malignancy worldwide with the fifth highest mortality rate among tumors in males, and there are unmet clinical needs for PCa treatment. In this work, we aim to explore the expression and overlap between B7 Homolog 3 protein (B7-H3) and cell-surface receptor c-mesenchymal-epithelial transition factor (c-MET), to provide insight on B7-H3 and c-MET bi-specific ADC drugs development for advanced PCa.

PATIENTS AND METHODS

In this retrospective cross-sectional study, formalin-fixed paraffin-embedded (FFPE) samples were analyzed from 135 male patients with advanced PCa at Hubei Cancer Hospital between 2019 and 2023. Biomarker and drug information were collected and used as major factors for patient stratification. Protein expression of B7-H3 (D9M2L) and c-MET (SP44) were determined by staining intensity and percent staining measurements. Positive expression of B7-H3 was defined as H Score ≥100, and positive expression of c-MET was defined as H Score >0. Historical medical information related to these cases were collected and the data were analyzed by R.

RESULTS

44% samples had both positive B7-H3 expression and c-MET expression, but c-MET expression is higher in peri-tumor sites than it in tumor site in PCa. The expression of B7-H3 and c-MET did not demonstrate significant correlation with age, metastatic site, or disease control rate (DCR). In addition, progression-free survival (PFS) of B7-H3 negative c-MET positive group was significantly shorter compared to the rest groups in patients receiving androgen deprivation therapy (ADT), while the expression of two markers was not significantly correlated with PFS in patients receiving ADT and new androgen receptor (AR) antagonists.

CONCLUSIONS

In conclusion, B7-H3 is a promising drug developing target for PCa; however, c-MET may be limited by its low expression in tumor site while relative higher expression in peri-tumor site in PCa. Further investigation is warranted regarding bi-specific drugs for B7-H3 and another marker.

Cardiovascular events among men with prostate cancer treated with androgen receptor signaling inhibitors: a systematic review, meta-analysis, and network meta-analysis

BACKGROUND

Androgen-receptor pathway inhibitors (ARPIs) have dramatically changed the management of advanced/metastatic prostate cancer (PCa). However, their cardiovascular toxicity remains to be clarified.

OBJECTIVE

To analyze and compare the risks of cardiovascular events secondary to treatment of PCa patients with different ARPIs.

METHODS

In August 2023, we queried PubMed, Scopus, and Web of Science databases to identify randomized controlled studies (RCTs) that analyze PCa patients treated with abiraterone, apalutamide, darolutamide, and enzalutamide. The primary outcomes of interest were the incidence of cardiac disorder, heart failure, ischemic heart disease (IHD), atrial fibrillation (AF), and hypertension. Network meta-analyses (NMAs) were conducted to compare the differential outcomes of each ARPI plus androgen deprivation therapy (ADT) compared to standard of care (SOC).

RESULTS

Overall, 26 RCTs were included. ARPIs were associated with an increased risk of cardiac disorders (RR: 1.74, 95% CI: 1.13-2.68, p = 0.01), heart failure (RR: 2.49, 95% CI: 1.05-5.91, p = 0.04), AF (RR: 2.15, 95% CI: 1.14-4.07, p = 0.02), and hypertension (RR: 2.06, 95% CI: 1.67-2.54, p < 0.01) at grade ≥3. Based on NMAs, abiraterone increased the risk of grade ≥3 cardiac disorder (RR:2.40, 95% CI: 1.42-4.06) and hypertension (RR:2.19, 95% CI: 1.77-2.70). Enzalutamide was associated with the increase of grade ≥3 AF(RR: 3.17, 95% CI: 1.05-9.58) and hypertension (RR:2.30, 95% CI: 1.82-2.92).

CONCLUSIONS

The addition of ARPIs to ADT increases the risk of cardiac disorders, including IHD and AF, as well as hypertension. Each ARPI exhibits a distinct cardiovascular event profile. Selecting patients carefully and vigilant monitoring for cardiovascular issues is imperative for those undergoing ARPI + ADT treatment.

Current diagnostic and therapeutic options in de novo low-volume metastatic hormone-sensitive prostate cancer

INTRODUCTION

de novo low-volume metastatic hormone-sensitive prostate cancer (mHSPC) patients are characterized by a limited number of metastases at diagnosis. Intensifying the current diagnostic and therapeutic approach including multimodality therapy seems to be key in the clinical management of such patients.

AREAS COVERED

We comprehensively review the current staging and treatment options for de novo low-volume mHSPC.

EXPERT OPINION

PSMA-PET should be used in staging high-risk prostate cancer to detect metastatic disease and better stratify patients for individualized treatment. In the era of Androgen Receptor Pathway Inhibitors (ARPIs), Androgen Deprivation Therapy (ADT) alone should be considered an undertreatment for the majority of the patients. Based on current data in the literature, the most effective therapeutic strategy seems to be the combination of intensified systemic treatment (including ADT + ARPI) and radiotherapy for the primary tumor. The role of cytoreductive radical prostatectomy is currently being investigated as well as metastasis-directed therapy to metastatic sites.

Synergistic targeting strategies for prostate cancer

Prostate cancer is the second most commonly diagnosed cancer and the fifth leading cause of death among men worldwide. Androgen deprivation therapy is a common prostate cancer treatment, but its efficacy is often hindered by the development of resistance, which results in reducing survival benefits. Immunotherapy showed great promise in treating solid tumours; however, clinically significant improvements have not been demonstrated for patients with prostate cancer, highlighting specific drawbacks of this therapeutic modality. Hence, exploring novel strategies to synergistically enhance the efficacy of prostate cancer immunotherapy is imperative. Clinical investigations have focused on the combined use of targeted or gene therapy and immunotherapy for prostate cancer. Notably, tumour-specific antigens and inflammatory mediators are released from tumour cells after targeted or gene therapy, and the recruitment and infiltration of immune cells, including CD8+ T cells and natural killer cells activated by immunotherapy, are further augmented, markedly improving the efficacy and prognosis of prostate cancer. Thus, immunotherapy, targeted therapy and gene therapy could have reciprocal synergistic effects in prostate cancer in combination, resulting in a proposed synergistic model encompassing these three therapeutic modalities, presenting novel potential treatment strategies for prostate cancer.

Association of the circulating lipid panel, PCPro, with clinical outcomes in metastatic hormone-sensitive prostate cancer: post hoc analysis of the ENZAMET phase III randomised trial (ANZUP 1304)

BACKGROUND

Enzalutamide significantly improves overall survival (OS) of patients with metastatic hormone-sensitive prostate cancer (mHSPC). However, ∼10% of patients will die within 2 years. PCPro is a plasma lipid panel associated with decreased OS in metastatic castration-resistant prostate cancer. In this study, we assessed the association between PCPro and clinical outcomes in mHSPC by carrying out a post hoc analysis of ENZAMET, the landmark phase III trial comparing enzalutamide with nonsteroidal anti-androgen (NSAA).

PATIENTS AND METHODS

PCPro status was determined by liquid chromatography-mass spectrometry analysis of plasma samples from 866 participants (77% of the ENZAMET trial cohort), before treatment (n = 866) and at first progression (n = 282). Outcomes examined were OS and clinical progression-free survival (clinPFS).

RESULTS

Participants with a positive PCPro status at baseline (13.4%) had a significantly shorter OS and clinPFS compared with those with a negative PCPro status [OS hazard ratio (HR) 1.81, 95% CI 1.40-2.33, clinPFS HR 1.65, 95% CI 1.32-2.07, P < 0.0001]. PCPro is an independent prognostic factor when modelled with key clinical prognostic factors (P < 0.001). Enzalutamide (compared with NSAA) improved the OS of PCPro-negative participants (HR 0.61, P < 0.0001), but not the survival of PCPro-positive participants (HR 1.10, P = 0.69; interaction P = 0.024). Participants who were PCPro positive at progression have a shorter OS than those who were negative, irrespective of baseline status (median OS 24-28 months versus 42-45 months).

CONCLUSIONS

PCPro status is a prognostic biomarker and predictive of the lack of OS benefit from enzalutamide compared with NSAA in mHSPC. These findings provide a rationale for testing therapeutic agents that can modify circulating lipid profiles in mHSPC.

Current landscape in first-line treatment of metastatic hormone sensitive prostate cancer: a cost-effectiveness focused review

Contemporary treatment of metastatic hormone-sensitive prostate cancer (mHSPC) has evolved significantly over the past decade with the introduction of upfront combination therapies (ie, ADT plus androgen receptor pathway inhibitors (ARPIs), with or without docetaxel), previously reserved for more advanced stages of the disease. However, the evidence is still controversial regarding the benefit of triple combinations beyond high volume disease (HVD) compared to double combinations, particularly those consisting of ADT + ARPIs. In addition, financial considerations regarding net benefits make these treatment regimens an unfavorable option from a cost-effectiveness standpoint, an element that becomes even more relevant in resource-limited contexts. Considering the lack of head-to-head trials for the direct comparison of triplets vs. ADT + ARPIs in different subgroups (as most evidence of specific combination superiority comes from indirect comparison in meta-analyses and the questionable cost-effectiveness profile triplets have shown), we propose that the current role of triplets is reserved for synchronous, HVD mHSPC in a resource-rich setting. Consequently, our work proposes a treatment algorithm that weighs the OS benefit according to the clinical risk of each patient subgroup and the availability of clinical resources. In this current scenario of abundant options, future research will focus on clarifying the selection of the most appropriate treatment for each patient according to their clinical characteristics and re-evaluating the cost-effectiveness of treatments as new drugs and generics emerge.

Selective treatment de-escalation in advanced prostate cancer: have we come full circle?

Compelling evidence has solidified the notion of early treatment intensification in managing patients with metastatic hormone-sensitive prostate cancer (mHSPC). Landmark trials have provided Level 1 evidence for the survival benefits achieved by combining multiple agents. The efficacy of combined therapy relies not only on how treatment is intensified but also on how it is de-escalated. This underscores the importance of tailored treatment approaches, potentially involving a reduction in therapy for specific patients, to strike a balance between the benefits of hormonal treatment and its associated adverse effects. While de-escalation of therapy in mHSPC remains challenging due to limited evidence, it is recommended for elderly or frail patients, those with poor performance status, or experiencing significant toxicity. However, for patients with excellent prostate-specific antigen responses or favourable biomarkers, decisions should be personalised, weighing the potential benefits of continued treatment against the risk of long-term side effects, using risk stratification tools where appropriate.

Prognostic Nutritional Index as a Biomarker in Metastatic Hormone-Sensitive Prostate Cancer: Impact on Survival and Treatment Optimization

OBJECTIVE

The Prognostic Nutritional Index (PNI), reflects the nutritional and immunological status of the patient and has been associated with outcomes in various cancers. In this study, the prognostic significance of PNI in metastatic hormone-sensitive prostate cancer (mHSPC) and its potential role in guiding treatment decisions between abiraterone acetate and enzalutamide is investigated.

METHODS

Retrospective analysis was performed on 167 mHSPC patients treated between 2019 and 2024. PNI was calculated using the formula: 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (/mm³). Patients were stratified into high and low PNI groups according to a cutoff value of 49.98, determined via receiver operating characteristic (ROC) analysis. Survival outcomes, including overall survival (OS), radiographic progression-free survival (rPFS), and PSA progression-free survival (PSA-PFS), were assessed. Treatment responses to abiraterone acetate and enzalutamide were compared within PNI strata.

RESULTS

Patients with PNI > 49.98 had significantly longer median OS than those with PNI ≤ 49.98 (36.6 months vs. 30.0 months, p < 0.01). Multivariate analysis identified high PNI, ECOG performance status 0-1, and absence of visceral metastasis as independent predictors of improved OS. Among patients with low PNI, those treated with enzalutamide had superior OS compared to those receiving abiraterone acetate (p = 0.004), while no significant OS difference was noted between treatments in the high PNI group (p = 0.55).

CONCLUSION

PNI serves as a significant prognostic biomarker in mHSPC, correlating with overall survival and potentially influencing treatment efficacy between abiraterone acetate and enzalutamide. Integrating PNI into clinical practice may aid in tailoring individualized treatment options.

Stereotactic body radiotherapy for lung oligometastatic prostate cancer: An international retrospective multicenter study

Background

Management of prostate cancer (PCa) patients with lung oligometastases remains unclear in the absence of published data.

Objective

The aim of this study was to evaluate the efficacy of Stereotactic Body Radiotherapy (SBRT) in this setting.

Design setting and participants

We conducted a multicenter retrospective study that included 35 PCa patients treated with SBRT for lung oligometastases in 7 centers across 3 countries.

Outcome measurements and statistical analysis

The efficacy was evaluated by the progression free-survival (PFS), defined as pre-SBRT PSA + 25 % or nadir PSA + 25 % and + 2 ng/mL or radiological progression if it occurred before biochemical progression. The local recurrence free-survival (LRFS), distant metastases free-survival (DMFS), Overall Survival (OS) and Androgen Deprivation Therapy free-survival were also assessed. Survival was estimated using the Kaplan Meier method.

Results

35 patients were included with lung oligometastases staged with PET-CT for 97 % and histologically biopsy confirmed for 51 %. 77 % had an oligorecurrent metastatic disease. The median pre SBRT PSA was at 1.7 ng/mL [0.8, 3.0] and the median follow-up after SBRT was 28.7 months. The median PFS was 21.6 months [95 %CI: 21.6; NA] and the median DMFS was 32.4 months [95 %CI: 22.2-NA]. No parameters were significantly associated with PFS on the univariate and multivariate models.For patients who did not start ADT before or concomitantly with SBRT (n = 18), the 1-year ADT free-survival rate was estimated at 87.2 % [71.9;100].

Conclusions

SBRT for PCa lung oligometastases offers good oncological outcomes, comparable to those reported for bone and/or lymph node metastases SBRT. Our results encourage the inclusion of patients with lung oligometastatic disease in clinical trials designed to assess the value of SBRT.

Patient summary

SBRT for prostate cancer lung oligometastases shows promising results, similar to treatments for bone or lymph node oligometastases.

Current role of salvage radiotherapy in oligometastatic prostate cancer at the time of recurrence

PURPOSE OF REVIEW

To review the evidence for metastasis-directed therapy (MDT) in oligometastatic (OM) prostate cancer (PC) and future directions in this clinical setting.

RECENT FINDINGS

The indications for radiotherapy in PC have significantly increased over the last decade. The treatment of OM disease has been gaining popularity thanks to new molecular imaging techniques that allow more accurate identification of OM patients who may benefit from MDT. stereotactic body radiation therapy can offer potentially curative treatment with low toxicity rates. Although most published MDT studies focus on hormone-sensitive (HS) PC in the setting of recurrence, promising results have emerged in recent years even in patients with castration resistance.

SUMMARY

MDT has emerged as an effective treatment option for OM PC patients with favorable oncological outcomes and a low toxicity profile. Evidence suggests that MDT can be used to delay androgen deprivation therapy or in combination with systemic therapy to potentially improve efficacy outcomes. Molecular stratification is needed to determine who will benefit from treatment intensification with MDT +/- systemic therapies.

HSD3B1, prostate cancer mortality and modifiable outcomes

Androgen receptor stimulation by testosterone and dihydrotestosterone is crucial for prostate cancer progression. Despite the initial effectiveness of androgen deprivation therapy (ADT), castration-resistant prostate cancer eventually develops in most men. A common germline missense-encoding polymorphism in HSD3B1 increases extra-gonadal androgen biosynthesis from adrenal precursors owing to increased availability of the encoded enzyme 3β-hydroxysteroid dehydrogenase 1 (3βHSD1) - hence, it is called the adrenal-permissive enzyme. This mechanism explains the more rapid progression to castration-resistant prostate cancer in men who inherit this allele than in men without it via sustained androgen receptor activation despite ADT. Multiple clinical studies, including data derived from prospective phase III studies, have linked adrenal-permissive allele inheritance to inferior clinical responses to ADT and increased mortality, but reversal is possible with upfront adrenal androgen blockade. The adrenal-permissive allele exhibits divergent frequencies across various groups worldwide, which could contribute to differences in clinical outcomes among these populations. Large-scale data from the Million Veteran Program have shown homozygous HSD3B1 adrenal-permissive allele inheritance to be an independent biomarker of prostate cancer-specific mortality. Together, these observations support the integration of HSD3B1 into germline testing and clinical trials as it might help to identify groups at increased likelihood of benefiting from early, intensified, AR-targeting interventions. Lastly, 3βHSD1 is a promising target for pharmacological inhibition, which enables new strategies for systemic prostate cancer therapy.

Percentage of free to total PSA as a biomarker of survival in metastatic castration-resistant prostate cancer

OBJECTIVE

To analyse whether the percentage of free to total prostate-specific antigen (%fPSA) is a prognostic biomarker in metastatic castration-resistant prostate cancer (mCRPC), as novel studies suggest an elevated %fPSA is associated with adverse oncological outcomes for men with biochemical recurrence of prostate cancer.

PATIENTS AND METHODS

A biobank prospectively collated at mCRPC diagnosis was analysed for %fPSA. Clinicopathological characteristics, systemic therapies and survival outcomes were recorded. Patients were stratified by a %fPSA cut-off of 15%. Cox proportional hazard models evaluated whether %fPSA was associated with overall survival (OS) and cancer-specific survival (CSS) across the cohort and by treatment.

RESULTS

A total of 254 patients analysed with newly diagnosed mCRPC: 161 (63%) men having a %fPSA ≥15%. The median follow-up was 25.6 months. The median cohort OS and CSS was 39.6 and 43.8 months, respectively. Patients with a %fPSA ≥15% had lower median PSA level (31.30 vs 50.80 ng/mL; P = 0.007) and otherwise comparable clinicopathological and treatment profiles to men with a %fPSA <15%. Adjusting for PSA and on multivariable analysis, a %fPSA ≥15% was associated with shorter OS (multivariable hazard ratio [HR] 1.56, 95% confidence interval [CI] 1.02-2.40; P = 0.039). Among men treated with docetaxel, a %fPSA ≥15% was associated with worse OS (HR 1.84, 95% CI 1.03-3.26; P = 0.038) and CSS. Conversely, %fPSA was not associated with outcomes for men receiving androgen receptor pathway inhibitors (abiraterone acetate or enzalutamide).

CONCLUSION

An elevated %fPSA appears to be an adverse prognostic biomarker. Findings are consistent with biochemical recurrence studies, suggesting a biological basis. Validation and mechanistic studies are warranted.

A visual whole-body tumor-burden classification based on PSMA PET/CT to predict response to novel androgen receptor signaling inhibitors for metastatic hormone-sensitive prostate cancer patients

PURPOSE

The incidence rates of metastatic hormone-sensitive prostate cancer (mHSPC) have increased rapidly. Androgen deprivation therapy (ADT) with AR signaling inhibitors (ARSIs) has been determined survival benefit for mHSPC patients in several randomized trials. However, patients do not respond uniformly. Whole-body tumor-burden schemes guided by prostate-specific membrane antigen (PSMA) PET/CT have been proven to be a useful predictive tool for PSMA-targeted radioligand therapy (RLT), while the value for hormone therapy was unclear. We hypothesized a visual whole-body tumor-burden classification based on PSMA PET/CT can enable selective patient stratification and prognostic evaluation for hormone treatment.

MATERIALS AND METHODS

Patients diagnosed with de novo mHSPC through pathological test and [18F]F-PSMA PET/CT between February 2022 and December 2023 who received ADT alone or ADT plus first-generation antiandrogens or ADT plus second-generation/novel ARSIs in our hospital were included. Only can hormone treatments (ADT or ADT plus first-generation antiandrogens or ADT plus novel ARSIs) be adopted at least six months after initial diagnosis. Prostate Cancer Multidisciplinary Team (MDT) of our hospital proposed a newly visual whole-body tumor-burden scheme based on PSMA PET/CT (MDT scheme: high vs. low): MDT high group (fulfilling any one of the three following criteria): (I) the number of metastatic lesions is more than 10 (diffused involvement of single bone is counted as 4 lesions) and PSMA uptake levels of 80% lesions are higher than that of parotid glands, (II) the presence of visceral metastases, (III) at least 4 bone metastases (≥ 1 beyond the vertebral bodies or the pelvis). In addition, other three tumor-burden classification methods (PSMA-CHAARTED, PSMA-LATITUDE, revised-vPSG schemes) were also assessed in this study. A series of other parameters including SUV-derived features of PSMA PET/CT and potential clinical and pathological factors were evaluated. SUV-derived features were determined for measurable locations and included: SUVmax, SUVpeak, SUVmean and tumor volume (TV) of prostatic primary lesions, the highest SUVmax of all lesions in whole body (wbSUVmax), primary-tumor SUVmax ratio backgrounds (including blood pool of liver/ spleen/ mediastinum/parotid glands), wbSUVmax ratio backgrounds above. Serum prostate-specific antigen (PSA) lower than 0.2 ng/ml after six-month hormone treatment was set as the primary endpoint for prediction of PSA response. PSA99 (PSA reduction ≥ 99%) was the second endpoint for survival analysis. All parameters above including the four tumor-burden classification schemes were evaluated for the predictive and prognostic value according to the endpoints using logistic and Cox proportional hazards regression analysis, respectively. All P values < 0.05 were considered significant.

RESULTS

A total of 165 patients were included. The average age was 69.30 ± 8.12 years. In univariate logistic regression analysis, MDT, PSMA-CHAARTED, revised-vPSG tumor-burden classifications, type of hormone treatment and primary-tumor TV were significantly related to PSA response, and PSMA-LATITUDE scheme wasn't relevant to PSA response. The results of further multivariate logistic regression revealed MDT scheme (MDT high group vs. low group: OR = 5.34, 95%CI: 2.40-11.87, P < 0.001), type of hormone treatment (ADT + second-generation ARSIs vs. ADT alone or ADT + first-generation antiandrogens: OR = 0.21, 95%CI: 0.08-0.53, P = 0.001), and primary-tumor TV (≥ 12.49 cm3 vs. < 12.49 cm3: OR = 2.93, 95%CI: 1.25-6.89, P = 0.014) were proven to be independent significant predictors for mHSPC patients. Subgroups analysis of patients treated with ADT + second-generation ARSIs (N = 133) showed MDT, PSMA-CHAARTED, PSMA-LATITUDE, revised-vPSG tumor-burden classifications and primary-tumor TV were significantly associated with PSA response through univariate analysis, and in multivariate regression MDT scheme (MDT high group vs. low group: OR = 5.73, 95%CI: 2.47-13.30, P < 0.001) and primary-tumor TV (≥ 12.49 cm3 vs. < 12.49 cm3: OR = 2.75, 95%CI: 1.09-6.96, P = 0.032) were independent significant predictors for PSA response of novel ARSIs. The AUC of three-predictors model of 165 mHSPC patients was 0.740 (95% CI: 0.664-0.816, P < 0.001). The AUC of two-predictors model of 133 mHSPC patients treated with ADT + novel ARSIs was 0.751 (95% CI: 0.666-0.836, P < 0.001). Univariate survival analysis revealed that patients treated with ADT + second-generation ARSIs were prone to obtaining PSA remission in shorter period (P < 0.001). In multivariate Cox regression, MDT scheme (MDT high group vs. low group: HR = 0.52, 95%CI: 0.36-0.74, P < 0.001) and type of hormone treatment (ADT + second-generation ARSIs vs. ADT alone or ADT + first-generation antiandrogens: HR = 3.34, 95%CI: 2.02-5.54, P < 0.001) were demonstrated to be independent significant prognostic indicators of patients with mHSPC. The survival analysis of patients treated with ADT + second-generation ARSIs (N = 133), patients with low burden of MDT (P < 0.001) or PSMA-CHAARTED (P = 0.029) or PSMA-LATITUDE (P = 0.009) could achieve PSA 99% reduction faster, and the low and high group patients based on revised-vPGS weren't displayed the significant difference in PSA99. Through the multivariate Cox survival regression, only MDT scheme (MDT high group vs. low group: HR = 0.47, 95%CI: 0.33-0.69, P < 0.001) was selected as the independent significant prognostic biomarker for mHSPC patients treated with ADT + second-generation ARSIs.

CONCLUSION

The visual whole-body tumor-burden classification based on PSMA PET/CT should be an effective stratification strategy for mHSPC patients treated with ADT + ARSIs, especially with ADT + second-generation ARSIs. PSA99 (PSA reduction ≥ 99%) could be a superior endpoint for patients with HSPC. This classification scheme could be a promising method for stratifying mHSPC patients. These findings need to be confirmed and validated through a longer follow-up, prospective and clinical data.

Impact of PSMA PET on Radiation Oncology Planning

Radiation therapy (RT) plays a critical role in managing prostate cancer (PCa) in various stages, from localized disease to metastatic settings. Recent advancements in molecular imaging using prostate-specific membrane antigen positron emission tomography (PSMA-PET) have revolutionized PCa diagnosis, significantly enhancing local, lymph node and distant stagingto conventional imaging methods. This narrative review explores the impact of PSMA-PET on RT planning, highlighting its diagnostic performance and implications for RT treatment management. PSMA-PET has shown superior sensitivity in detecting metastatic lesions and intraprostatic tumor volumes, leading to more accurate disease staging and treatment planning. The HypoFocal trials investigate the safety and efficacy of implementing PSMA-PET into definitive RT regimens. Additionalongoing clinical trials are investigating the potential of PSMA-PET-based RT recurrent and oligometastatic PCa. Despite these advancements, further research is necessary to optimize patient selection and define the best management strategies for PSMA-PET-guided RT.

Prostate Cancer: A Review

Importance

Prostate cancer is the most common nonskin cancer in men in the US, with an estimated 299 010 new cases and 35 250 deaths in 2024. Prostate cancer is the second most common cancer in men worldwide, with 1 466 680 new cases and 396 792 deaths in 2022.

Observations

The most common type of prostate cancer is adenocarcinoma (≥99%), and the median age at diagnosis is 67 years. More than 50% of prostate cancer risk is attributable to genetic factors; older age and Black race (annual incidence rate, 173.0 cases per 100 000 Black men vs 97.1 cases per 100 000 White men) are also strong risk factors. Recent guidelines encourage shared decision-making for prostate-specific antigen (PSA) screening. At diagnosis, approximately 75% of patients have cancer localized to the prostate, which is associated with a 5-year survival rate of nearly 100%. Based on risk stratification that incorporates life expectancy, tumor grade (Gleason score), tumor size, and PSA level, one-third of patients with localized prostate cancer are appropriate for active surveillance with serial PSA measurements, prostate biopsies, or magnetic resonance imaging, and initiation of treatment if the Gleason score or tumor stage increases. For patients with higher-risk disease, radiation therapy or radical prostatectomy are reasonable options; treatment decision-making should include consideration of adverse events and comorbidities. Despite definitive therapy, 2% to 56% of men with localized disease develop distant metastases, depending on tumor risk factors. At presentation, approximately 14% of patients have metastases to regional lymph nodes. An additional 10% of men have distant metastases that are associated with a 5-year survival rate of 37%. Treatment of metastatic prostate cancer primarily relies on androgen deprivation therapy, most commonly through medical castration with gonadotropin-releasing hormone agonists. For patients with newly diagnosed metastatic prostate cancer, the addition of androgen receptor pathway inhibitors (eg, darolutamide, abiraterone) improves survival. Use of abiraterone improved the median overall survival from 36.5 months to 53.3 months (hazard ratio, 0.66 [95% CI, 0.56-0.78]) compared with medical castration alone. Chemotherapy (docetaxel) may be considered, especially for patients with more extensive disease.

Conclusions and Relevance

Approximately 1.5 million new cases of prostate cancer are diagnosed annually worldwide. Approximately 75% of patients present with cancer localized to the prostate, which is associated with a 5-year survival rate of nearly 100%. Management includes active surveillance, prostatectomy, or radiation therapy, depending on risk of progression. Approximately 10% of patients present with metastatic prostate cancer, which has a 5-year survival rate of 37%. First-line therapies for metastatic prostate cancer include androgen deprivation and novel androgen receptor pathway inhibitors, and chemotherapy for appropriate patients.

Cost-Effectiveness Analysis of Contemporary Advanced Prostate Cancer Treatment Sequences

There has been a proliferation of novel treatments for the management of advanced prostate cancer (PCa), including androgen receptor pathway inhibitors (ARPI). Although there are health economic analyses of novel PCa treatments, such as ARPIs for specific health states, there is a lack of sequential analyses. Our paper aims to fill this gap. We developed a Monte Carlo Markov model to simulate the management of advanced PCa to end-of-life. We modeled patients who begin in metastatic and nonmetastatic castration-sensitive PCa (mCSPC and nmCSPC), with risk stratification for mCSPC, progressing to metastatic castration-resistant PCa (mCRPC). Using current guidelines and recent literature, we simulated admissible treatment sequences over these states along a 15-year horizon. We report the best treatment sequences in terms of efficacy and cost-effectiveness. We find that the most cost-effective use of ARPIs is early in advanced PCa for a cost-effectiveness threshold (CET) of CAD 100K per QALY. For a CET of CAD 50K per QALY, early ARPI use is most cost-effective in mCSPC-starting patients but not nmCSPC-starting. We conclude that the most cost-effective way to use ARPIs is when patients first enter advanced PCa. The most cost-effective ARPI at current Canadian prices is abiraterone, mostly due to abiraterone's lower price level.

The impact of androgen receptor pathway inhibitors as starting treatment in metastatic castration-sensitive prostate cancer on patient outcomes (OASIS Japan)

We examined the impact of starting treatment on clinical outcomes in men with metastatic castration-sensitive prostate cancer (mCSPC). This retrospective observational cohort study used claims data from the Medical Data Vision (MDV) hospital-based administrative dataset in Japan. All patients with newly diagnosed mCSPC from 1 January 2018 to 31 March 2024 were enrolled and followed up until 30 September 2024. Time-to-event analyses used Kaplan-Meier methods. The risk of death, onset of castration resistance, time to ≥ 50% PSA decline (PSA50), ≥ 90% PSA decline (PSA90), and undetectable PSA level (≤ 0.2 ng/mL) was compared between androgen receptor pathway inhibitors (ARPIs) and combined androgen blockade (CAB) or androgen-deprivation therapy (ADT) alone using a Cox proportional hazard model adjusted for age, body mass index, co-morbidities, visceral metastases, and baseline PSA. 22,559 patients with mCSPC had received relevant treatment of whom 15,797 were included in the analysis: 1167 (5.2%) started on apalutamide (APA) + ADT, 1407 (6.2%) on enzalutamide + ADT, 1262 (5.6%) on abiraterone acetate plus prednisone + ADT, and 11,961 (53.0%) on CAB/ADT alone. The median age was between 74 and 78 years in each group. Bone metastases were present in 60.5% to 72.6% of patients, visceral metastases in 2.8% to 5.7%, and nodal metastases in 19.3% to 29.4%. Overall survival and castration resistance-free survival were significantly longer in patients initially treated with APA + ADT compared to CAB/ADT (p < 0.0001 for both comparisons). In patients with regular PSA assessment, a higher percentage of patients starting with APA + ADT achieved PSA50, PSA90 and undetectable PSA at 3 months compared with CAB/ADT (p < 0.0001, p = 0.0005, p < 0.0001, respectively). Use of APA + ADT as a starting treatment for mCSPC was associated with better clinical outcomes versus traditional CAB or ADT in real-world clinical practice in Japan.

When You Get to the Fork in the Road, Take It: The Challenges in Managing Patients With Advanced Prostate Cancer

As is the case with most solid tumors, the heterogeneity of the disease biology of prostate cancer presents clinicians managing this disease with daily challenges. However, in contrast to other common cancers such as breast, lung, and colorectal cancers, there are unique challenges in prostate cancer management, including the variety of clinicians who manage aspects of the disease (urologists, medical oncologist, radiation oncologists) and the striking absence of prospective comparative data to inform the optimal sequence of systemic therapy in patients with metastatic castration-resistant disease. The purpose of this review is to attempt to assist practicing oncologists with sorting through the myriad of prostate cancer disease subsets and the challenges in making therapeutic decisions in multiple data-free zones given the absence of level 1 comparative clinical trials in the metastatic hormone-sensitive and castration-resistant states.

Enzalutamide and Docetaxel in Combination With Androgen Deprivation for Men With Metastatic Hormone-Sensitive Prostate Cancer: ENZADA, a Phase II Trial

BACKGROUND

Androgen receptor pathway inhibitors (ARPI) in combination with docetaxel (Doc) and androgen deprivation therapy (ADT) has improved outcomes for men with metastatic hormone sensitive prostate cancer (mHSPC). We hypothesized that combining ADT with Doc and enzalutamide (Enz) would improve the 52-week prostate-specific antigen (PSA) complete response (CR) rate compared to a historical control with ADT + Doc.

METHODS

In a single arm phase II trial, treatment-naïve patients with mHSPC received ADT + Doc every 3 weeks up to 6 cycles and Enz daily until progression. The primary endpoint was 52-week PSA CR. Secondary endpoints included safety/toxicity, best PSA response, time to castration resistance and overall survival (OS).

RESULTS

Between Sep 2017 and Aug 2021, 40 patients were enrolled and 36 evaluable for the primary endpoint. At data cutoff, median follow up was 56.1 months. Thirty patients (75%) had high-volume disease. Median age was 64.5 years. Median pretreatment PSA was 129.5ng/ml. 52-week PSA CR occurred in 22/36 (61.1%) patients compared to historical control (P < .001). Median OS was not reached. Patients who did not achieve a 52-week PSA CR had shorter OS (HR, 4.67; 95% CI 1.41-15.55; P = .006). Treatment-related Grade 3 to 5 adverse events occurred in 17/40 (42.5%) patients.

CONCLUSION

ADT+Doc+Enz improved 52-week PSA CR compared to historical control with ADT+Doc. Achieving a PSA CR after 1 year of therapy correlated with improved OS. These results are consistent with recent phase III studies and support using triplet regimens that combine ADT+Doc+ARPI for newly diagnosed mHSPC.

Combination Therapies in Locally Advanced and Metastatic Hormone-sensitive Prostate Cancer

BACKGROUND AND OBJECTIVE

The treatment landscape for advanced prostate cancer has evolved significantly over the past decade. The introduction of docetaxel, androgen receptor pathway inhibitors (ARPIs), poly(ADP-ribose) polymerase inhibitors, and targeted radionuclides has redefined the treatment paradigm, with a focus now on early treatment intensification through combination therapies. This narrative collaborative review summarises the current evidence of combination therapies in locally advanced and metastatic hormone-sensitive prostate cancer (mHSPC).

METHODS

We conducted a literature search up to November 2024. Search terms included "metastatic hormone-sensitive prostate cancer", "metastatic castration-sensitive prostate cancer", "locally advanced prostate cancer", "combination", "intensification", and "de-escalation". Articles were selected by the authors based on their scientific merit, clinical impact, and relevance to provide a summary of the evidence surrounding combination therapy in locally advanced prostate cancer and mHSPC.

KEY FINDINGS AND LIMITATIONS

A doublet approach with an androgen deprivation therapy (ADT) backbone and an ARPI is now considered the standard treatment for mHSPC, with a triplet regimen incorporating docetaxel considered in select subgroups. Similar efforts to improve survival in the high-risk localised and locally advanced disease setting have led to several trials evaluating the benefit of combination therapy in addition to standard-of-care surgery or radiotherapy with ADT. Continued improvements in survival have turned the focus to optimising patient selection for treatment intensification and, in some cases, de-escalation, with the goal of reducing unnecessary overtreatment and minimising harm from long-term treatment toxicity. This is particularly important with the integration of prostate-specific membrane antigen positron emission tomography, which has led to the earlier detection of metastatic disease.

CONCLUSIONS AND CLINICAL IMPLICATIONS

In select subgroups, early treatment intensification with combination therapy leads to improved survival, though it can be associated with long-term toxicity.

Integrating Prostate Specific Membrane Antigen-PET into Clinical Practice for Prostate Cancer

Prostate surface membrane antigen (PSMA)-PET imaging has significantly shaped the clinical management of prostate cancer, from localized to metastatic disease. It outperforms conventional imaging in both primary staging and detecting recurrence. PSMA-PET incorporation into the clinical workflow can alter treatment decisions, though the impact of observed stage migration on patient outcomes has yet to be well-characterized. There is growing interest in using PSMA-PET to predict treatment response across all stages of prostate cancer, and to select patients for PSMA radioligand therapy. Use of PSMA-PET will continue to expand for clinical applications as its role becomes better defined through prospective studies.

TET3 is expressed in prostate cancer tumor-associated macrophages and is associated with anti-androgen resistance

PURPOSE

The aim of this study is to investigate the expression of TET3 in prostate cancer and its effect on the efficacy of anti-androgen therapy (ADT).

METHODS

The expression of TET3 in 1965 cases of prostate cancer and 493 cases of normal prostate tissues were analyzed. The CIBERSORT algorithm evaluated the abundance of 22 tumor-infiltrating immune cells in 497 prostate cancers. Subsequently, the expression of TET3 in prostate cancer TAMs was analyzed using 21,292 cells from single-cell RNA sequencing (scRNAseq). In addition, the trajectory of the differentiation process was reconstructed based on pseudotime analysis. Sensitivity prediction of prostate cancers to ADT was evaluated based on GDSC2 and CTRP databases. Another dataset GSE111177 was employed for further analysis.

RESULTS

TET3 was over-expressed in prostate cancer, and the expression of TET3 in metastatic prostate cancer was higher than that in non-metastatic prostate cancer. The scRNAseq analysis of prostate cancer showed that TET3 was mainly expressed in TAM. TET3 expressed in early and active TAMs, with the activation of signaling pathways such as energy metabolism, cell communication, and cytokine production. Prostate cancer in TET3 high expression group was more sensitive to ADT drugs such as Bicalutamide and AZD3514, and was also more sensitive to chemotherapy drugs such as Cyclophosphamide, Paclitaxel, and Vincristine, and MAPK pathway inhibitors of Docetaxel and Dabrafenib.

CONCLUSIONS

The efficacy of ADT in prostate cancer is related to the expression of TET3 in TAMs, and TET3 may be a potential therapeutic target for coordinating ADT.

Triplet therapy for metastatic castration-sensitive prostate cancer: Rationale and clinical evidence

Prostate cancer (PC) growth is hormone-dependent and it frequently develops distant metastases as disease progresses. Patients with metastatic castration-sensitive prostate cancer (mCSPC) initially respond to androgen deprivation therapy (ADT) but eventually become refractory and develop metastatic castration-resistant prostate cancer (mCRPC). Castration-resistance is associated with high lethality and metastases confer poor prognosis, therefore unmet needs in treatment for mCSPC remain high. So far, improvements in survival in mCSPC have been achieved by doublet combination therapy such as docetaxel or an androgen-receptor signaling inhibitor (ARSI) in addition to ADT. Further, recent phase 3 trials have shown that triplet therapy-a combination of ARSI, docetaxel, and ADT improves prognosis compared with docetaxel plus ADT in mCSPC. PC tumors manifest intra- and inter-tumoral heterogeneity at both the genetic and phenotypic level. As heterogeneity increases during sequential treatment and disease progression, it is reasonable to initiate combination therapy using drugs with different mechanisms of action early in the course of disease, such as mCSPC. Previous research about tumor heterogeneity and drug resistant mechanism support this rationale, as well as preclinical studies and real-world data provide the scientific evidence of benefit by combining ARSI and docetaxel. Here, we review the rationale and clinical evidence for triplet therapy in patients with mCSPC.

Incidence, Management, and Prevention of Gynecomastia and Breast Pain in Patients with Prostate Cancer Undergoing Antiandrogen Therapy: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Background and objective

In patients with prostate cancer treated with antiandrogen monotherapy, gynecomastia and breast pain are relatively common. In the setting of androgen receptor pathway inhibitors (ARPIs), the incidence of these adverse events (AEs) remains unclear. In addition, the effect of prophylactic treatment on gynecomastia remains uncertain. We aimed to evaluate the incidence of gynecomastia and breast pain in prostate cancer patients treated with ARPIs compared with androgen deprivation therapy (ADT) and the effect of prophylactic treatment for these AEs due to antiandrogen therapy.

Methods

In June 2024, we queried four databases-PubMed, Scopus, Web of Science, and Embase-for randomized controlled trials (RCTs) investigating prostate cancer treatments involving antiandrogen therapy. The endpoints of interest were the incidence of these AEs due to ARPIs and the effect of prophylactic treatment for these.

Key findings and limitations

Eighteen RCTs, comprising 5036 patients, were included in the systematic review and meta-analysis. ARPIs included enzalutamide, darolutamide, and apalutamide. The results indicated that patients who received ARPI monotherapy had a significantly higher incidence of gynecomastia than those who received ADT monotherapy (risk ratio [RR]: 5.19, 95% confidence interval [CI]: 3.58-7.51, p < 0.001). There was no significant difference in the incidence of gynecomastia between ARPI plus ADT therapy and ADT monotherapy (RR: 1.27, 95% CI: 0.84-1.93, p = 0.2). Prophylactic tamoxifen or radiotherapy reduced significantly the incidence of gynecomastia and breast pain caused by bicalutamide monotherapy.

Conclusions and clinical implications

We found that ARPI monotherapy increases the incidence of these AEs significantly compared with ADT. In contrast, ARPI plus ADT therapy did not result in a higher incidence of AEs. The use of either tamoxifen or radiotherapy was effective in reducing the incidence of these AEs due to bicalutamide monotherapy. These prophylactic treatments could reduce the incidence of AEs due to ARPI monotherapy. However, further studies are needed to clarify their efficacy.

Patient summary

Although androgen deprivation therapy (ADT) improves overall survival in patients with prostate cancer, it is associated with several complications. Androgen receptor pathway inhibitor (ARPI) monotherapy has emerged as a promising strategy for improving oncological outcomes in these patients. However, ARPI monotherapy increases gynecomastia and breast pain in prostate cancer patients compared with ADT, while ARPI plus ADT did not result in a higher incidence of adverse events.

The Predictive Role of the Gleason Score in Determining Prognosis to Systematic Treatment in Metastatic Castration-Sensitive Prostate Cancer: A Systematic Review and Network Meta-Analysis

Background: Gleason scores of 8 or higher indicate a poorer prognosis in metastatic castration-sensitive prostate cancer (mCSPC). This study aims to perform a systematic review and network meta-analysis (NMA) to compare overall survival (OS) and progression-free survival (PFS) among combination therapies with androgen receptor signaling inhibitors (ARSIs) in mCSPC patients, stratified by Gleason score ≥8 and <8. Methods: A literature search was conducted across PubMed, Embase, and Web of Science, using a PRISMA-guided systematic search strategy, covering January 2013 to June 2024. Results: Twelve studies including 12,652 patients were included in the NMAs. In the overall population, most ARSI combination therapies improved survival outcomes, except for orteronel + androgen deprivation therapy (ADT). In the Gleason score ≥8 subgroup, all ARSI combination therapies improved OS, with rezvilutamide showing the highest probability of being the best treatment for OS (HR 0.48, 95% CI 0.31-0.76, P-scores 0.88). In the Gleason score <8 subgroup, only darolutamide + docetaxel + ADT (HR 0.49, 95% CI 0.29-0.81) and apalutamide + ADT (HR 0.67, 95% CI 0.46-0.98) improved OS. Conclusions: ARSI combination therapy is effective for mCSPC patients with Gleason score ≥8, but further investigation is needed to confirm its efficacy in patients with Gleason score <8.

On-treatment PSA kinetics as a potential biomarker: Guiding personalized treatment in metastatic hormone-sensitive prostate cancer

In this issue of Med, Bian et al. present a post-hoc analysis of the phase 3 CHART trial investigating rezvilutamide in the metastatic hormone-sensitive prostate cancer setting.1 They show that patients achieving a deep PSA response at six months had significantly improved outcomes. These findings could impact patient counseling and support the potential role of on-treatment PSA kinetics in personalizing therapy.

Management of Patients with Advanced Prostate Cancer. Report from the 2024 Advanced Prostate Cancer Consensus Conference (APCCC)

BACKGROUND AND OBJECTIVE

Innovations have improved outcomes in advanced prostate cancer (PC). Nonetheless, we continue to lack high-level evidence on a variety of topics that greatly impact daily practice. The 2024 Advanced Prostate Cancer Consensus Conference (APCCC) surveyed experts on key questions in clinical management in order to supplement evidence-based guidelines. Here we present voting results for questions from APCCC 2024.

METHODS

Before the conference, a panel of 120 international PC experts used a modified Delphi process to develop 183 multiple-choice consensus questions on eight different topics. Before the conference, these questions were administered via a web-based survey to the voting panel members ("panellists").

KEY FINDINGS AND LIMITATIONS

Consensus was a priori defined as ≥75% agreement, with strong consensus defined as ≥90% agreement. The voting results show varying degrees of consensus, as discussed in this article and detailed in the Supplementary material. These findings do not include a formal literature review or meta-analysis.

CONCLUSIONS AND CLINICAL IMPLICATIONS

The voting results can help physicians and patients navigate controversial areas of clinical management for which high-level evidence is scant or conflicting. The findings can also help funders and policymakers in prioritising areas for future research. Diagnostic and treatment decisions should always be individualised on the basis of patient and cancer characteristics, and should incorporate current and emerging clinical evidence, guidelines, and logistic and economic factors. Enrolment in clinical trials is always strongly encouraged. Importantly, APCCC 2024 once again identified important gaps (areas of nonconsensus) that merit evaluation in specifically designed trials.

PSMA PET/CT SUVmax as a prognostic biomarker in patients with metachronous metastatic hormone-sensitive prostate cancer (mHSPC)

BACKGROUND

Metastatic hormone-sensitive prostate cancer (mHSPC) is treatment-resistant and generally considered incurable. The development of prostate-specific membrane antigen positron emission-computed tomography (PSMA PET/CT) has generated immense expectations due to its diagnostic accuracy in prostate cancer (PCa). PSMA expression of the primary tumor, quantified by SUVmax, is a predictor of oncological outcomes. The role of PSMA-PET/CT SUVmax in metachronous mHSPC treated with ADT plus second-generation antiandrogens (ARSI) is unknown. The main aim of this study was to evaluate 68Ga-PSMA-11expression (SUVmax) as a potential prognostic biomarker in patients with metachronous mHSPC treated with ADT and first or second-generation antiandrogens. A second aim was to determine the association between PSMA SUVmax and PSA response to hormone therapy.

MATERIAL AND METHODS

Patients diagnosed with metachronous mHSPC between July 2017 and February 2023 who developed biochemical recurrence following radical surgery (with or without salvage radiotherapy and/or ADT) or external radiation therapy (with or without ADT) were included. All patients underwent 68 Ga-PSMA-11 PET/CT imaging and the SUVmax value was determined for all measurable locations. The SUVmax value was used for the semiquantitative analysis. The Wilcoxon method was used to compare responders (PSA reduction ≥ 50%) to non-responders (PSA reduction < 50%). The SUVmax value and hormone therapy were evaluated as independent variables relative to the PSA response rate or PSA reduction using the linear regression method. A mixed-effects model (ANOVA) was used for the comparisons.

RESULTS

A total of 82 patients were included. Median follow-up was 11.7 months. On the linear regression analysis, patients with a high SUVmax treated with ADT + ARSI showed a greater PSA response (p = 0.034) than those treated with ADT + first-generation antiandrogens. In the mixed-effects model, SUVmax was significant (p = 0.041). On the univariate analysis, PSA at recurrence (HR, 3.2; 95% CI: 1.07-13.6; p = 0.078) and the number of metastases (HR, 4.77; 95% CI 1.1-26.1: p = 0.002) were associated with the type of hormone therapy administered.

CONCLUSIONS

PSMA-PET/CT SUVmax is a prognostic biomarker that can be used to predict a PSA response to ADT + ARSI in patients with metachronous mHSPC. However, these findings need to be confirmed in larger prospective studies.

Central Nervous System Toxicity in Prostate Cancer Patients Treated with Androgen Receptor Signaling Inhibitors: A Systematic Review, Meta-analysis, and Network Meta-analysis

BACKGROUND

Androgen-receptor signaling inhibitors (ARSIs) significantly improve survival in systemic therapy for advanced/metastatic prostate cancer (PCa) patients; however possible central nervous system (CNS) toxicity is an unaddressed concern. We aimed to assess and compare the incidence of CNS-related adverse events (AEs) secondary to the treatment of PCa patients with different ARSIs.

MATERIALS

In August 2023, a comprehensive seach was conducted in three databases for randomized controlled trials (RCTs) of PCa patients receiving ARSIs plus ADT. The primary endpoints included mental impairment, cognitive impairment, seizure, fatigue, and falls.

RESULTS

Twenty-six RCTs, comprising 20,328 patients, were included in meta-analyses and network meta-analyses (NMAs). ARSIs increased the risk of mental impairment (RR: 1.72; 95% CI, 1.09-2.71), cognitive impairment (RR: 2.25; 95% CI, 1.78-2.86), seizure (RR: 2.20, 95% CI, 1.09-4.45), fatigue (RR: 1.31, 95% CI, 1.20-1.43), and falls (RR: 2.07, 95% CI, 1.60-2.67) compared to standard of care (SOC). Based on NMAs, Enzalutamide showed a significant increase in risk for all assessed CNS-related AEs, while Abiraterone demonstrated significant risk increases in cognitive impairment, fatigue, and falls. Conversely, Darolutamide did not exhibit significant increases in risk for any CNS-related AEs, except for fatigue.

CONCLUSIONS

The addition of ARSIs to ADT increased all examined CNS-related AEs compared to SOC. Each ARSI is associated with a distinct profile of CNS-related AEs. Careful patient selection and monitoring for CNS sequelae is necessary to achieve the best quality of life in patients on ARSI + ADT for PCa.

An Updated Systematic Review and Network Meta-Analysis of First-Line Triplet vs. Doublet Therapies for Metastatic Hormone-Sensitive Prostate Cancer

Purpose: The addition of androgen receptor pathway inhibitors (ARPIs) to androgen deprivation therapy (ADT), with or without docetaxel (Doc), is currently recommended for metastatic, hormone-sensitive prostate cancer (mHSPC). Recently, the ARANOTE trial evaluated the efficacy and safety of Darolutamide + ADT in this setting. We aimed to update a network meta-analysis (NMA) of these combination therapies. Methods: We conducted a systematic search for RCTs on systemic therapies for mHSPC using MEDLINE, Embase, and the Web of Science Core Collection in September 2024. An NMA utilizing random-effects models was performed to compare progression-free survival (PFS), overall survival (OS), and adverse event (AE) incidence (PROSPERO: CRD42024591458). Results: A total of 12 RCTs (n = 11,954) were included in our NMAs. Triplet therapies were associated with significant improvements in PFS compared to ARPI-based doublet therapies (hazard ratio [HR]: 0.74; 95% confidence interval [CI]: 0.59-0.93; p = 0.01), but the difference did not reach the conventional levels of statistical significance for OS (HR: 0.82; 95% CI: 0.67-1.01; p = 0.059). In a subset analysis, compared to ARPI-based doublet therapies, triplet therapies showed a significant improvement in PFS in patients with high-volume disease (HR: 0.64; 95% CI: 0.47-0.88; p < 0.01), whereas no significant improvement was observed in those with low-volume disease (HR: 0.86; 95% CI: 0.45-1.67; p = 0.7). No significant difference in grade ≥ 3 AEs was observed between triplet therapies and ARPI-based doublet therapies. The main limitations include patient heterogeneity and limited follow-up in some studies. Conclusions: Triplet therapies can improve the oncologic outcomes of patients with mHSPC compared to ARPI-based doublet therapies, without significantly increasing severe AEs. These findings warrant further confirmation in a head-to-head trial powered for overall survival.

Physician Reasons for or Against Treatment Intensification in Patients With Metastatic Prostate Cancer

Importance

Clarifying the underutilization of treatment intensification (TI) for metastatic castration-sensitive prostate cancer (mCSPC) may improve implementation of evidence-based medicine and survival outcomes.

Objective

To investigate physicians' beliefs about TI in mCSPC to understand the gap between evidence-based guidelines and clinical practice.

Design, Setting, and Participants

This survey study analyzed data from the Adelphi Real World retrospective survey, which comprised physician surveys that were linked to medical record reviews of US adult patients treated for mCSPC between July 2018 and January 2022.

Main Outcomes and Measures

The survey included questions on physician and practice demographics. Physicians completed patient record forms, based on patient medical records with information including patient demographics, clinical characteristics, and patient management. Physicians recalled reasons for prescribing decisions using 48 precoded and open-text responses. Bivariate and multivariable analyses assessed the likelihood of their patients receiving first-line TI; the main outcome was the likelihood of their patients receiving TI using odds ratios (ORs).

Results

In total, 617 male patients met the analysis criteria (mean [SD] age, 68.6 [8.1] years). Among these patients, 349 (56.6%) were Medicare beneficiaries. Overall, 430 (69.7%) did not receive first-line TI with androgen receptor pathway inhibitors and/or chemotherapy. The 107 US-based physicians' top reasons for treatment choice for their patients were tolerability concerns (TI: 121 [64.7%]; no TI: 252 [58.6%]; P = .18) and following guideline recommendations (TI: 115 [61.5%]; no TI: 230 [53.5%]; P = .08). In the bivariate analysis, physicians seeking to reduce prostate-specific antigen (PSA) by 75% to 100% were more likely to provide first-line TI compared with physicians who aimed to lower PSA by 0% to 49% (OR, 1.63 [95% CI, 1.04-2.56]; P = .03). In the multivariable analysis, patients whose physicians based treatment choice on guidelines were more likely to receive TI than patients whose physicians did not report this reason (OR, 3.46 [95% CI, 1.32-9.08]; P = .01).

Conclusions and Relevance

The findings of this study, which analyzed data from a medical records-linked clinical practice survey, indicated low rates of first-line TI for mCSPC despite guideline recommendations. Barriers to TI included lack of knowledge about guidelines and published efficacy and safety data. Physicians with greater PSA reduction goals were more likely to use TI. Physician education on treatment guidelines and clinical trial data, while raising expectations for PSA response, may increase rates of first-line TI in mCSPC.

Epidemiology of men with synchronous metastatic prostate cancer diagnosis - A nationwide 26-year temporal analysis

BACKGROUND

Evolving imaging modalities, increased awareness, and prostate-specific antigen testing in men with synchronous metastatic prostate cancer (mHSPC) are expected to have prolonged survival. Here we analyze trends in survival among men diagnosed with synchronous metastatic prostate cancer in Denmark.

METHODS

Here, we included all men diagnosed with mHSPC (N = 12,017) in Denmark between January 1st, 1995, and December 31st, 2021. Men were followed until December 31st, 2022. Median time to death was calculated by the Kaplan Meier method and the 3-year risk of prostate cancer death per calendar year was estimated by the Aalen-Johansen estimator from time of diagnosis.

FINDINGS

Median follow-up was 9 years (IQR: 4-15), from 2015 59 % of the men with mHSPC had treatment beyond androgen depletion therapy. Median survival increased from 1.7 years (IQR: 1·3-2·0) to 3.8 years (IQR: 3·3-4·2) in men diagnosed in 1995 and 2018, respectively (p < 0·001), after which median survival was not reached. The prostate cancer-specific mortality three years after diagnosis decreased from 66 % (95 %CI: 60-72) in 1995 to 28 % (95 %CI: 25-32) in 2019 (p < 0·001). From the period 1995-1999 to 2015-2021 median overall survival increased from 1·7 years (IQR: 0·8-3·7) to 4·5 years (IQR: 2·4-not reached; p < 0·001) in men age < 65 years and from 1·5 years (IQR: 0·7-2·9) to 3·1 years (IQR: 1·6-5·7; p < 0.001) in men older than 74 years at diagnosis.

INTERPRETATION

The improved survival suggests that, among other contributing factors, implementing novel therapies has likely been efficacious outside the clinical trial setting. Still, most men diagnosed with synchronous metastatic prostate cancer will die of prostate cancer. As such the need for life-prolonging and age-tailored treatment trials remains evident.

Treatment Intensification With Novel Hormonal Therapy in Castration-Sensitive Prostate Cancer: Patient Identification and Clinical Rationale

The clinical rationale for treatment of castration-sensitive prostate cancer (CSPC) with novel hormonal therapy (NHT) or androgen receptor pathway inhibitor is reviewed. A PubMed search was conducted to identify relevant publications on NHTs for CSPC treatment. Level 1 clinical evidence demonstrated that intensification of androgen deprivation therapy (ADT) with NHT prolongs life and improves or maintains quality of life in patients with metastatic CSPC (mCSPC). Despite these results, real-world evidence demonstrated that 47%-88% of patients with mCSPC are treated with single agent ADT. Possible explanations for the underutilization of NHTs include patient characteristics, misperceptions about the overall survival benefit, lack of physician and patient awareness of the magnitude of clinical trial results, physician bias, safety concerns, misconceptions about the magnitude of prostate-specific antigen response needed for patient improvement, and barriers to NHT access. For patients with biochemical recurrence and no evidence of metastatic disease, limited clinical data exist with no consensus on an effective treatment strategy. Therefore, treatment strategies are developed using patient risk stratification according to clinicopathological characteristics, genomics, and next-generation imaging. Patients with high-risk biochemical recurrence may benefit from the early initiation of NHT based on outcomes from the phase III EMBARK trial. Lifestyle management is also an important aspect of treatment for CSPC, helping to mitigate the side effects of hormonal treatment and ensuring patients can maintain treatment while optimizing quality of life. In conclusion, to improve outcomes in patients with mCSPC, it is important to implement solutions addressing the barriers to underutilization of treatment intensification.

Multi-institutional Analysis of Metastasis-directed Therapy with or Without Androgen Deprivation Therapy in Oligometastatic Castration-sensitive Prostate Cancer

BACKGROUND

Metastasis-directed therapy (MDT) is increasingly being used in oligometastatic castration-sensitive prostate cancer (omCSPC). However, it is currently unclear how to optimally integrate MDT with the standard of care of systemic hormonal therapy.

OBJECTIVE

To report long-term outcomes of MDT alone versus MDT and a defined course of androgen deprivation therapy (ADT) in omCSPC.

DESIGN, SETTING, AND PARTICIPANTS

Here, a multicenter, international retrospective cohort of omCSPC as defined by conventional imaging was reported.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Biochemical progression-free survival (bPFS), distant progression-free survival (dPFS), and combined biochemical or distant progression-free survival (cPFS) were evaluated with Kaplan-Meier and multivariable Cox proportional hazard regression models.

RESULTS AND LIMITATIONS

A total of 263 patients were included, 105 with MDT + ADT and 158 with MDT alone. The majority of patients had metachronous disease (90.5%). Five-year bPFS, dPFS, and cPFS were, respectively, 24%, 41%, and 19% in patients treated with MDT + ADT and 11% (hazard ratio [HR] 0.48, 95% confidence interval [CI] 0.36-0.64), 29% (HR 0.56, 95% CI 0.40-0.78), and 9% (HR 0.50, 95% CI 0.38-0.67) in patients treated with MDT alone. On a multivariable analysis adjusting for pretreatment variables, the use of ADT was associated with improved bPFS (HR 0.43, p < 0.001), dPFS (HR 0.45, p = 0.002), and cPFS (HR 0.44, p < 0.001).

CONCLUSIONS

In this large multi-institutional report, the addition of concurrent ADT to MDT appears to improve time to prostate-specific antigen progression and distant recurrence, noting that about 10% patients had durable control with MDT alone. Ongoing phase 3 studies will help further define treatment options for omCSPC.

PATIENT SUMMARY

Here, we report a large retrospective review evaluating the outcomes of metastasis-directed therapy with or without a limited course of androgen deprivation for patients with oligometastatic castration-sensitive prostate cancer. This international multi-institutional review demonstrates that the addition of androgen deprivation therapy to metastasis-directed therapy (MDT) improves progression-free survival. While a proportion of patients appear to have long-term disease control with MDT alone, further work in biomarker discovery is required to better identify which patients would be appropriate for de-escalated therapy.

A modified Delphi consensus regarding the clinical utility of triplet therapy in patients with metastatic hormone-sensitive prostate cancer patients in the UK

OBJECTIVES

This study aimed to determine the clinical utility of the androgen deprivation therapy (ADT)+docetaxel (DOCE)+androgen receptor-targeted agent (ARTA) triplet therapy in patients with metastatic hormone-sensitive prostate cancer (mHSPC) in the UK.

DESIGN

A modified Delphi method. A steering group of eight UK healthcare professionals experienced in prostate cancer care discussed treatment challenges, developing 39 consensus statements across four topics. Agreement with the statements was tested with a broader panel of professionals within this therapeutic area in the UK through an anonymous survey, using a four-point Likert scale. This was distributed by the steering group members and an independent third party. Following the survey, the steering group convened to discuss the results and formulate recommendations.

SETTING

The steering group convened online for discussions. The survey was distributed via email by the clinicians and the independent third party.

PARTICIPANTS

Healthcare professionals involved in the provision of prostate cancer care, working in relevant professional roles (oncology, urology or geriatric consultant, oncology nurse specialist, and hospital pharmacist) within the UK. No patients or members of the public were involved within the study.

INTERVENTIONS

None.

PRIMARY AND SECONDARY OUTCOME MEASURES

Consensus was defined as high (≥75% agreement) and very high (≥90% agreement).

RESULTS

Responses were received from 120 healthcare professionals, including oncologists (n=73), urologists (n=16), geriatricians (n=15), nurse specialists (n=11) and hospital pharmacists (n=5). Consensus was reached for 37 out of 39 (95%) statements, and 27/39 (69%) statements achieved very high agreement ≥90%. Consensus was not reached for 2/39 (5%) statements.

CONCLUSIONS

Based on the consensus observed, the steering group developed a set of recommendations for the clinical utility of ADT+DOCE+ARTA in treating patients with mHSPC in the UK. Following these recommendations enables clinicians to identify appropriate patients with mHSPC for triplet treatment, thereby improving patients' outcomes.

Efficacy and safety of prostate radiotherapy in de novo metastatic castration-sensitive prostate cancer (PEACE-1): a multicentre, open-label, randomised, phase 3 study with a 2 × 2 factorial design

BACKGROUND

The 2 × 2 PEACE-1 study showed that combining androgen-deprivation therapy with docetaxel and abiraterone improved overall and radiographic progression-free survival in patients with de novo metastatic castration-sensitive prostate cancer. We aimed to examine the efficacy and safety of adding radiotherapy in this population.

METHODS

We conducted an open-label, randomised, controlled, phase 3 trial with a 2 × 2 factorial design (PEACE-1) at 77 hospitals across Europe. Eligible participants were male patients (aged ≥18 years) with de novo metastatic castration-sensitive prostate cancer confirmed by bone scan, CT, or MRI, and an Eastern Cooperative Oncology Group performance status of 0-1 (or 2 in the case of bone pain). Participants were randomly assigned (1:1:1:1) to standard of care (androgen-deprivation therapy alone or with six cycles of intravenous docetaxel 75 mg/m2 every 3 weeks), standard of care plus abiraterone (oral 1000 mg abiraterone once daily plus oral 5 mg prednisone twice daily), standard of care plus radiotherapy (74 Gy in 37 fractions to the prostate), or standard of care plus radiotherapy and abiraterone. Participants and investigators were not masked to treatment allocation. The coprimary endpoints were radiographic progression-free survival and overall survival, analysed by intention to treat in patients with low-volume metastatic disease and in the overall study population. This ongoing study is registered with EudraCT, 2012-000142-35.

FINDINGS

Between Nov 27, 2013, and Dec 20, 2018, 1173 patients were enrolled and 1172 were randomly assigned to receive standard of care (n=296 [25·3%]), standard of care plus abiraterone (n=292 [24·9%]), standard of care plus radiotherapy (n=293 [25·0%]), and standard of care plus abiraterone and radiotherapy (n=291 [24·8%]). Median follow-up was 6·0 years (IQR 5·1-7·0) at the time of radiographic progression-free survival and overall survival analysis. A qualitative interaction between radiotherapy and abiraterone for radiographic progression-free survival in the population of patients with low-volume disease prevented the pooling of intervention groups for analysis (p=0·026). Adding radiotherapy to standard of care improved radiographic progression-free survival in patients with low-volume disease treated with abiraterone (median 4·4 years [99·9% CI 2·5-7·3] in the standard of care plus abiraterone group vs 7·5 years [4·0-not reached] in the standard of care plus abiraterone and radiotherapy group; adjusted hazard ratio [HR] 0·65 [99·9% CI 0·36-1·19]; p=0·019), but not in patients not treated with abiraterone (median 3·0 years [99·9% CI 2·3-4·8] in the standard of care group vs 2·6 years [1·7-4·6] in the standard of care plus radiotherapy group; 1·08 [0·65-1·80]; p=0·61). For overall survival, the predefined threshold for a statistical interaction was not reached (p=0·12); therefore, the two intervention groups receiving radiotherapy were pooled together for analysis. In patients with low-volume disease, the overall survival was not influenced by radiotherapy (median 6·9 years [95·1% CI 5·9-7·5] for standard of care with or without abiraterone vs 7·5 years [6·0-not reached] for standard of care plus radiotherapy with or without abiraterone; HR 0·98 [95·1% CI 0·74-1·28]; p=0·86). In the overall safety population, 339 (56·1%) of 604 patients who did not receive radiotherapy and 329 (58·8%) of 560 patients who received radiotherapy developed at least one severe adverse event (grade ≥3), the most common being hypertension (110 [18·2%] patients in the standard of care with or without abiraterone group and 127 [22·7%] in the standard of care plus radiotherapy with or without abiraterone group) and neutropenia (40 [6·6%] and 29 [5·2%]).

INTERPRETATION

Combining radiotherapy with standard of care plus abiraterone improves radiographic progression-free survival and castration resistance-free survival, but not overall survival in patients with low-volume de novo metastatic castration-sensitive prostate cancer. Radiotherapy reduces the occurrence of serious genitourinary events, regardless of metastatic burden and without increasing the overall toxicity, and could become a component of standard of care in patients with both high-volume and low-volume de novo metastatic castration-sensitive prostate cancer.

FUNDING

Janssen-Cilag, Ipsen, Sanofi, and Institut National du Cancer.

Azolato-Bridged Dinuclear Platinum(II) Complexes Exhibit Androgen Receptor-Mediated Anti-Prostate Cancer Activity

Prostate cancer is an androgen-dependent malignancy that presents a marked treatment challenge, particularly after progression to the castration-resistant stage. Traditional treatments such as androgen deprivation therapy often lead to resistance, necessitating novel therapeutic approaches. Previous studies have indicated that some of the azolato-bridged dinuclear platinum(II) complexes (general formula: [{cis-Pt(NH3)2}2(μ-OH)(μ-azolato)]X2, where azolato = pyrazolato, 1,2,3-triazolato, or tetrazolato and X = nitrate or perchlorate) inhibit androgen receptor (AR) signaling. Therefore, here we investigated the potential of 14 such complexes as agents for the treatment of prostate cancer by examining their antiproliferative activity in the human prostate adenocarcinoma cell line LNCaP. Several of the complexes, particularly 5-H-Y ([{cis-Pt(NH3)2}2(μ-OH)(μ-tetrazolato-N2,N3)](ClO4)2), effectively inhibited LNCaP cell growth, even at low concentrations, by direct modulation of AR signaling, and by binding to DNA and inducing apoptosis, which is a common mechanism of action of Pt-based drugs such as cisplatin (cis-diamminedichloridoplatinum(II)). Comparative analysis with cisplatin revealed superior inhibitory effects of these complexes. Further investigation revealed that 5-H-Y suppressed mRNA expression of genes downstream from AR and induced apoptosis, particularly in cells overexpressing AR, highlighting its potential as an AR antagonist. Thus, we provide here insights into the mechanisms underlying the antiproliferative effects of azolato-bridged complexes in prostate cancer.

Androgen receptor pathway inhibitors and drug-drug interactions in prostate cancer

Prostate cancer represents a major global health challenge, necessitating efficacious therapeutic strategies. Androgen receptor pathway inhibitors (ARPIs) have become central to prostate cancer treatment, demonstrating significant effectiveness in both metastatic and non-metastatic contexts. Abiraterone acetate, by inhibiting androgen synthesis, deprives cancer cells androgens necessary for growth, while second-generation androgen receptor (AR) antagonists disrupt AR signaling by blocking AR binding, thereby impeding tumor progression. Given the predominance of prostate cancer in the elderly, who often present with multiple comorbidities requiring complex pharmacological regimens, the potential for drug-drug interactions with ARPIs is a critical concern. These interactions, particularly through pathways like CYP2D6 inhibition by abiraterone and CYP3A4 induction by enzalutamide and apalutamide, necessitate a thorough understanding to optimize therapeutic outcomes and minimize adverse effects. This review aims to delineate the efficacy of ARPIs in prostate cancer management and elucidate their interaction with common medications, highlighting the importance of vigilant drug management to optimize patient care.

Recommendations on the treatment of metastatic hormone-sensitive prostate cancer: Patient selection

The standard treatment for metastatic hormone-sensitive prostate cancer (mHSPC) is now a combination of androgen deprivation therapy plus an androgen receptor-targeted therapy (abiraterone, apalutamide, enzalutamide or darolutamide), with or without chemotherapy (docetaxel). The selection of suitable patients for each therapeutic approach has become a determining factor to ensure efficacy and minimize side effects. This article combines recent clinical evidence with the accumulated experience of experts in medical oncology, radiation oncology and urology, to provide a comprehensive view and therapeutic recommendations for mHSPC.

Optimizing triple therapy in patients with metastatic hormone-sensitive prostate cancer

Triple therapy with docetaxel, androgen deprivation therapy (ADT) and androgen receptor pathway inhibitors (ARPIs) has demonstrated survival benefits in patients with metastatic hormone-sensitive prostate cancer (mHSPC), especially in those with high-risk disease. However, once the use of ADT and docetaxel is established, guidelines do not clearly specify which ARPI is most appropriate. In this work, a literature review to identify phase III clinical trials, systematic reviews, meta-analyses, and clinical practice guidelines on triple therapy in mHSPC was carried out. Evidence and recommendations were qualitatively reviewed to provide guidelines on the most suitable ARPI based on patient risk, disease volume, and nature of metastases (synchronous or metachronous). This review aims to update the previously published consensus on the optimal pharmacological treatment for mHSPC and to expose the opinions of hospital pharmacy, urology and medical and radiation oncology experts.

Inhibition of Androgen Receptor Exposes Replication Stress Vulnerability in Prostate Cancer

Standard initial systemic treatment for patients with metastatic prostate cancer includes agents that target androgen receptor (AR) signaling. Despite an initial positive response to these AR pathway inhibitors (ARPIs), acquired resistance remains a significant challenge. We show that treatment of AR-positive prostate cancer cells with the frontline ARPI enzalutamide induces DNA replication stress. Such stress is exacerbated by suppression of translesion DNA synthesis (TLS), leading to aberrant accumulation of single-stranded DNA (ssDNA) gaps and persistent DNA damage biomarkers. We further demonstrate that the TLS inhibitor, JH-RE-06, markedly sensitizes AR-positive prostate cancer cells, but not AR-negative benign cells, to enzalutamide in vitro. Combination therapy with enzalutamide and JH-RE-06 significantly suppresses cancer growth in a syngeneic murine tumor model over vehicle control or individual treatment groups. These findings suggest that AR inhibition broadly triggers DNA replication stress in hormone-sensitive prostate cancer, thereby exposing a unique vulnerability that can be exploited by a TLS-disrupting adjuvant for targeted therapy.

Real-world treatment trends for patients with advanced prostate cancer and renal cell carcinoma and their cost-a survey in Japan

BACKGROUND

Advanced (Stage IV) prostate and renal cancer have poor prognosis, and several therapies have been developed, but many are very costly. This study investigated drug regimens used in patients with untreated Stage IV prostate cancer and renal cell carcinoma and calculated the monthly cost of each.

METHODS

We surveyed first-line drugs administered to patients with untreated Stage IV prostate cancer and renal cancer at Japan Clinical Oncology Group affiliated centers from April 2022 to March 2023. Drug costs were calculated according to drug prices in September 2023. Individual drug costs were calculated or converted to 28-day costs.

RESULTS

A total of 700 patients with untreated Stage IV prostate cancer were surveyed. Androgen deprivation therapy + androgen receptor signaling inhibitor was the most common regimen (56%). The cost of androgen deprivation therapy + androgen receptor signaling inhibitor was 10.6-30.8-fold compared with conventional treatments. A total of 137 patients with Stage IV renal cancer were surveyed. Among them, 91% of patients received immune-oncology drug-based regimen. All patients received treatments with a monthly cost of ≥500 000 Japanese yen, and 80.4% of patients received treatments with a monthly cost of ≥1 million Japanese yen, of combination treatments. The cost of immune-oncology drug-based regimen was 1.2-3.1-fold that of TKI alone.

CONCLUSION

To the best of our knowledge, this is the first report of a survey of first-line drug therapy in untreated Stage IV prostate cancer and renal cell carcinoma stratified by age and treatment costs. Our results show that most Japanese patients received state-of-the-art, effective treatments with high financial burden.

A novel prognostic model of de novo metastatic hormone-sensitive prostate cancer to optimize treatment intensity

BACKGROUND

The treatment and prognosis of de novo metastatic hormone-sensitive prostate cancer (mHSPC) vary. We established and validated a novel prognostic model for predicting cancer-specific survival (CSS) in patients with mHSPC using retrospective data from a contemporary cohort.

METHODS

1092 Japanese patients diagnosed with de novo mHSPC between 2014 and 2020 were registered. The patients treated with androgen deprivation therapy and first-generation anti-androgens (ADT/CAB) were assigned to the Discovery (N = 467) or Validation (N = 328) cohorts. Those treated with ADT and androgen-receptor signaling inhibitors (ARSIs) were assigned to the ARSI cohort (N = 81).

RESULTS

Using the Discovery cohort, independent prognostic factors of CSS, the extent of disease score ≥ 2 or the presence of liver metastasis; lactate dehydrogenase levels > 250U/L; a primary Gleason pattern of 5, and serum albumin levels ≤ 3.7 g/dl, were identified. The prognostic model incorporating these factors showed high predictability and reproducibility in the Validation cohort. The 5-year CSS of the low-risk group was 86% and that of the high-risk group was 22%. Approximately 26.4%, 62.7%, and 10.9% of the patients in the Validation cohort defined as high-risk by the LATITUDE criteria were further grouped into high-, intermediate-, and low-risk groups by the new model with significant differences in CSS. In the ARSIs cohort, high-risk group had a significantly shorter time to castration resistance than the intermediate-risk group.

CONCLUSIONS

The novel model based on prognostic factors can predict patient outcomes with high accuracy and reproducibility. The model may be used to optimize the treatment intensity of de novo mHSPC.

Outcomes of First-Line Abiraterone Acetate or Enzalutamide for Older Adults With Metastatic Castration-Resistant Prostate Cancer According to Use of Upfront Docetaxel for Metastatic Castration-Sensitive Prostate Cancer in an International Multicenter Registry: A SPARTACUSS-Meet-URO 26 Study

BACKGROUND

Managing metastatic castration-resistant prostate cancer (mCRPC) in men aged ≥ 75 is challenging due to limited data. Regardless of age, in real-world clinical practice, most mCRPC still derive from failure of androgen deprivation therapy (ADT) with or without docetaxel (D) for metastatic castration-sensitive prostate cancer (mCSPC). As abiraterone acetate plus prednisone (AA) and enzalutamide (Enza) are common first-line treatments for mCRPC. The impact of prior use of D for mCSPC on the efficacy and safety of AA or Enza in this older population remains unclear.

METHODS

A cohort of patients aged ≥ 75 years starting AA or Enza as first-line therapy for mCRPC from January 2015 to April 2019 was identified from the registries of 10 institutions. Patients were categorized into 2 groups based on previous use of D for mCSPC. Primary endpoints were cancer-specific survival (CSS) from AA or Enza start, CSS from ADT onset, and safety. We used Kaplan-Meier method to estimate the endpoints distribution, including median values with 95% confidence intervals (95% CI).

RESULTS

Of the 337 patients identified, 24 (7.1%) received ADT+D and 313 (92.9%) received ADT alone for mCSPC. Median follow-up from AA/Enza start was 18.8 months. Median CSS from ADT or AA/Enza was not significantly different between ADT+D and ADT alone cohorts (71.9 vs. 52.7 months, P = .97; 25.4 vs. 27.2 months, P = .89, respectively). No statistically significant difference in adverse events (AEs) of any grade rate (58.3% vs. 52.1%, respectively; P = .67) or grade ≥ 3 (12.5% vs. 15.7%, respectively; P = 1.0) was found between ADT+D and ADT alone cohorts.

CONCLUSIONS

Despite the innate limitations of a retrospective design and relatively small size of the ADT+D cohort, this analysis suggests that elderly men receiving AA or Enza as first-line therapy for mCRPC have similar survival outcomes and tolerability, regardless of previous D for mCSPC.

The Rapidly Evolving Treatment Landscape of Metastatic Hormone-Sensitive Prostate Cancer

The management of metastatic hormone-sensitive prostate cancer (mHSPC) or castration-sensitive prostate cancer (mCSPC) has become increasingly complex with the tremendous progress that has been made in this space within the past few decades. In the early days of androgen deprivation therapy (ADT), ADT monotherapy was the mainstay for treatment of advanced prostate cancer. However, novel hormone therapies in the form of androgen receptor pathway inhibitors (ARPI) have emerged; vaccine therapy, chemotherapy with docetaxel and cabazitaxel, and radioactive ligands have shaped the treatment of metastatic prostate cancer in the last decade. Following the initial approval of several drugs for use in metastatic castration-resistant prostate cancer (mCRPC) in combination with primary ADT, these agents were studied and subsequently approved for use in mCSPC. Therefore, ADT monotherapy no longer constitutes an optimal therapeutic option for otherwise fit patients who present with mCSPC. We focus on the treatment of first-line de novo mHSPC or mCSPC and explore frontline doublet and triplet therapy and the pivotal trials that led to their United States Food and Drug Administration approval.

Novel Treatment Strategies for Low-Risk Metastatic Castration-Sensitive Prostate Cancer

BACKGROUND

The treatment strategy for metastatic castration-sensitive prostate cancer (mCSPC) has changed significantly in recent years. Based on various guidelines, an upfront androgen receptor signaling inhibitor (ARSI) is the first choice, but in patients of Asian descent, including Japanese patients, there are a certain number of cases in which androgen deprivation therapy (ADT) and CAB are more effective. If patients can be identified who show a marked response to ADT within 12 weeks after the initiation of ADT, which is the inclusion criterion for ARSI clinical trials targeting mCSPC, it would be valuable from an economic standpoint.

METHODS

A total of 218 patients with pure prostate adenocarcinoma and treated with ADT at the Kanazawa University Hospital between January 2000 and December 2020 were included in this study. As a risk classification for mCSPC, in addition to the LATITUDE and CHAARTED criteria, we used the castration-sensitive prostate cancer classification proposed by Kanazawa University (Canazawa), developed by the Department of Urology of Kanazawa University. The Canazawa classification was based on three factors: Gleason pattern 5, bone scan index (BSI) ≥ 1.5, and lactate dehydrogenase (LDH) ≥ 300 IU/L. It defined patients with one factor or less as low-risk and patients with two or three factors as high-risk. The overall survival (OS) and time to castration resistance (TTCR) were estimated retrospectively using the Kaplan-Meier method, and factors associated with TTCR were identified using univariate and multivariate analyses.

RESULTS

The median follow-up period was 40.4 months, the median OS period was 85.2 months, and the median TTCR period was 16.4 months. The Canazawa risk classification provided the clearest distinction between the OS and TTCR in mCSPC patients. Multivariate analysis revealed a decrease in PSA levels of <95% at 12 weeks after ADT initiation and was a predictor of short TTCR in low-risk, low-volume patients across all risk classifications.

CONCLUSION

The Canazawa classification differentiated the prognosis of mCSPC patients more clearly. A PSA reduction rate of <95% at 12 w after starting ADT in low-risk, low-volume patients of all risk classifications was significantly shorter than the TTCR. We propose a new treatment strategy, in which patients with low-risk mCSPC are treated with ADT and switched to ARSIs based on the rate of PSA reduction at 12 w.

Strategic Advances in Combination Therapy for Metastatic Castration-Sensitive Prostate Cancer: Current Insights and Future Perspectives

The contemporary treatment for metastatic castration-sensitive prostate cancer (mCSPC) has evolved significantly, building on successes in managing metastatic castration-resistant prostate cancer (mCRPC). Although androgen deprivation therapy (ADT) alone has long been the cornerstone of mCSPC treatment, combination therapies have emerged as the new standard of care based on recent advances, offering improved survival outcomes. Landmark phase 3 trials demonstrated that adding chemotherapy (docetaxel) and androgen receptor pathway inhibitors to ADT significantly enhances overall survival, particularly for patients with high-volume, high-risk, or de novo metastatic disease. Despite these advancements, a concerning gap between evidence-based guidelines and real-world practice remains, with many patients not receiving recommended combination therapies. The challenge in optimizing therapy sequences, considering both disease control and treatment burdens, and identifying clinical and biological subgroups that could benefit from personalized treatment strategies persists. The advent of triplet therapy has shown promise in extending survival, but the uro-oncology community must narrow the gap between evidence and practice to deliver the most effective care. Current research is focused on refining treatment approaches and utilizing biomarkers to guide therapy selection, aiming to offer more personalized and adaptive strategies for mCSPC management. Thus, aligning clinical practices with the evolving evidence is urgently needed to improve outcomes for patients facing this incurable disease.

Salvage therapies for biochemical recurrence after definitive local treatment: a systematic review, meta-analysis, and network meta-analysis

PURPOSE

Recent advancements in the management of biochemical recurrence (BCR) following local treatment for prostate cancer (PCa), including the use of androgen receptor signaling inhibitors (ARSIs), have broadened the spectrum of therapeutic options. We aimed to compare salvage therapies in patients with BCR after definitive local treatment for clinically non-metastatic PCa with curative intent.

METHODS

In October 2023, we queried PubMed, Scopus, and Web of Science databases to identify randomized controlled trials (RCTs) and prospective studies reporting data on the efficacy of salvage therapies in PCa patients with BCR after radical prostatectomy (RP) or radiation therapy (RT). The primary endpoint was metastatic-free survival (MFS), and secondary endpoints included progression-free survival (PFS) and overall survival (OS).

RESULTS

We included 19 studies (n = 9117); six trials analyzed RT-based strategies following RP, ten trials analyzed hormone-based strategies following RP ± RT or RT alone, and three trials analyzed other agents. In a pairwise meta-analysis, adding hormone therapy to salvage RT significantly improved MFS (HR: 0.69, 95% CI: 0.57-0.84, p < 0.001) compared to RT alone. Based on treatment ranking analysis, among RT-based strategies, the addition of elective nodal RT and androgen deprivation therapy (ADT) was found to be the most effective in terms of MFS. On the other hand, among hormone-based strategies, enzalutamide + ADT showed the greatest benefit for both MFS and OS.

CONCLUSIONS

The combination of prostate bed RT, elective pelvic irradiation, and ADT is the preferred treatment for eligible patients with post-RP BCR based on our analysis. In remaining patients, or in case of post-RT recurrence, especially for those with high-risk BCR, the combination of ADT and ARSI should be considered.

Challenges of estimating treatment effects after a positive interim analysis

BACKGROUND

This research investigates why a beneficial treatment effect reported at the first interim analysis (IA) may diminish at a subsequent analysis (SA). We examined three challenges in interpreting treatment effects from randomized clinical trials (RCTs) after the first positive IA: overestimation bias; non-proportional hazards; and heterogeneity in recruitment. We investigate how a penalized estimation method can address overestimation bias, and discuss additional factors to consider when interpreting positive IA results.

METHODS

We identified oncology RCTs reporting positive results at the initial IA and a SA for event-free (EFS) and overall survival (OS). We modeled: (1) the hazard ratio at IA (HRIA) versus its timing as measured by the information fraction (IF; i.e., events at IA versus total events sought); and (2), the ratio of HRIA to HRSA (rHR) versus the IF. This was repeated for HRIA adjusted for overestimation bias. Examples of the other two challenges were sought.

RESULTS

Amongst 71 RCTs, HRIA were positively associated with the IF (slope: EFS 0.83, 95 % CI 0.44-1.22; OS 0.25, 95 % CI 0.10-0.41). HRIA tended to exaggerate HRSA, and more so the lower the IF (slope rHR versus IF: EFS 0.10, 95 % CI - 0.22 to 0.42; OS 0.26, 95 % CI 0.07-0.46). Adjusted HRIA did not exaggerate HRSA (slope rHR versus IF: EFS - 0.14, 95 % CI - 0.67 to 0.39; OS 0.02, 95 % CI - 0.26 to 0.30). Examples of two other challenges are shown.

CONCLUSION

Overestimation bias, non-proportional hazards, and heterogeneity in recruitment and other important treatments should be considered when communicating estimates of treatment effects from positive IAs.