Cancer and Leukemia Group B 90203 (Alliance): Radical Prostatectomy With or Without Neoadjuvant Chemohormonal Therapy in Localized, High-Risk Prostate Cancer

Postradical prostatectomy prostate-specific antigen outcomes after 6 versus 18 months of perioperative androgen-deprivation therapy in men with localized, unfavorable intermediate-risk or high-risk prostate cancer: Results of part 2 of a randomized phase 2 trial

BACKGROUND

Patients with localized, unfavorable intermediate-risk and high-risk prostate cancer have an increased risk of relapse after radical prostatectomy (RP). The authors previously reported on part 1 of this phase 2 trial testing neoadjuvant apalutamide, abiraterone, prednisone, plus leuprolide (AAPL) or abiraterone, prednisone, and leuprolide (APL) for 6 months followed by RP. The results demonstrated favorable pathologic responses (tumor <5 mm) in 20.3% of patients (n = 24 of 118). Herein, the authors report the results of part 2.

METHODS

For part 2, patients were randomized 1:1 to receive either AAPL for 12 months (arm 2A) or observation (arm 2B), stratified by neoadjuvant therapy and pathologic tumor classification. The primary end point was 3-year biochemical progression-free survival. Secondary end points included safety and testosterone recovery (>200 ng/dL).

RESULTS

Overall, 82 of 118 patients (69%) enrolled in part 1 were randomized to part 2. A higher proportion of patients who were not randomized to adjuvant therapy had a favorable prostatectomy pathologic response (32.3% in nonrandomized patients compared with 17.1% in randomized patients). In the intent-to-treat analysis, the 3-year biochemical progression-free survival rate was 81% for arm 2A and 72% for arm 2B (hazard ratio, 0.81; 90% confidence interval, 0.43-1.49). Of the randomized patients, 81% had testosterone recovery in the AAPL group compared with 95% in the observation group, with a median time to recovery of <12 months in both arms.

CONCLUSIONS

In this study, because 30% of patients declined adjuvant treatment, part B was underpowered to detect differences between arms. Future perioperative studies should be biomarker-directed and include strategies for investigator and patient engagement to ensure compliance with protocol procedures.

The presence of intraductal carcinoma of prostate is a risk factor for poor pathologic response in men with high-risk prostate cancer receiving neoadjuvant therapy

OBJECTIVE

To explore the potential association between the presence of intraductal carcinoma of the prostate (IDC-P) on biopsy and pathologic response of primary tumor to neoadjuvant therapy in patients with high-risk prostate cancer.

METHODS

Eighty-five patients with high-risk localized/locally advanced prostate cancer (CaP) who were given 6-month neoadjuvant therapies of androgen deprivation therapy plus docetaxel or abiraterone prior to radical prostatectomy in 2 prospective trials were included in this study. The presence of IDC-P in biopsy pathology was rereviewed by 2 experienced pathologists. Favorable pathologic response was defined as pathologic complete response or minimal residual disease <5 mm on whole-mount histopathology. Characteristics of clinical and biopsy pathology variables were included in univariate and multivariate logistic regression analyses to identify risk factors for the prediction of favorable pathologic response on final pathology.

RESULTS

IDC-P was identified to be present on biopsy pathology of 35 patients (41.2%) while favorable pathologic responses were confirmed in 25 patients (29.4%). Initial prostate-specific antigen (PSA) (OR 3.592, 95% CI 1.176-10.971, P = 0.025) and the presence of IDC-P on biopsy pathology (OR 3.837, 95% CI 1.234-11.930, P = 0.020) were found to be significantly associated with favorable pathologic response in multivariate logistic regression analysis.

CONCLUSION

IDC-P on biopsy pathology was found to be an independent risk factor to predict a poor pathology response of primary CaP to neoadjuvant therapies.

Secondary analysis of late major gastrointestinal and genitourinary toxicities in unfavorable-risk prostate cancer patients receiving docetaxel: Insights from a randomized trial

BACKGROUND

This study sought to evaluate the late toxicity associated with neoadjuvant and concurrent docetaxel and radiation therapy in patients with prostate cancer.

METHODS

A secondary analysis was performed of the phase 3 multicenter randomized trial (Dana-Farber Cancer Institute 05-043) including 350 patients with nonmetastatic unfavorable-risk prostate cancer. Patients were randomized 1:1 to receive androgen deprivation therapy, radiation therapy, and docetaxel versus androgen deprivation therapy and radiation therapy. The study assessed the cumulative incidence rates of grade 2 and grade 3 or higher gastrointestinal, genitourinary, and sexual toxicity. A multivariable Fine and Gray's competing risks regression model adjusted for age at randomization and pelvic lymph node radiation therapy was used to evaluate the treatment effect of docetaxel on time to late genitourinary and gastrointestinal toxicities.

RESULTS

The study included 338 patients who primarily had minimal or no comorbidity (74.9%) and median age 66 years (interquartile range: 61,71). At a median follow-up of 10.2 years, docetaxel was not associated with increased risk of any grade 3 or higher (adjusted hazard ratio [AHR], 0.98; 95% confidence interval [CI], 0.36-2.67; p = .96) or grade 2 gastrointestinal (p = .75), genitourinary (p = .44), and sexual (p = .29) toxicity. Age was associated with increased grade 3 or higher (AHR, 1.08; 95% CI, 1.01-1.16; p = .03) and grade 2 gastrointestinal toxicity (AHR, 1.11; 95% CI, 1.03-1.20; p = .005). A nonsignificant trend (p = .09) toward increased late grade 3 or higher toxicity was observed for pelvic radiation therapy use.

CONCLUSIONS

Docetaxel combined with radiotherapy has an acceptable long-term toxicity profile.

Neoadjuvant chemohormonal therapy before radical prostatectomy in high-risk prostate cancer: a mini-review

High-risk localized prostate cancer (PCa) has the potential of recurrence and progression to a lethal phenotype, and neoadjuvant therapy followed by radical prostatectomy (RP) may be an option for these patients. Docetaxel has been recently shown to be an effective chemotherapeutic agent for high-volume metastatic hormone-sensitive PCa and metastatic castration-resistant PCa, and these increased efficacy create the impetus to assess the potential role of preoperative docetaxel in high-risk localized PCa. In this mini-review, we found that neoadjuvant chemohormonal therapy (NCHT) may be an effective neoadjuvant regimen to improve oncological outcome of high-risk PCa. However, the addition of docetaxel in the neoadjuvant setting would unavoidably increase the rate of adverse events, impose additional economic burdens. Therefore, suitable patient selection is crucial and pathological response might be a surrogate endpoint. Furthermore, we also found that molecular imaging prostate-specific membrane antigen (PSMA) PET/CT was a promising tool to evaluation the effectiveness of NCHT, and the expression status of AR, AR-V7, Ki-67, PTEN and TP53 might be helpful for urologists to identify more suitable candidates for NCHT.

Localized high-risk prostate cancer harbors an androgen receptor low subpopulation susceptible to HER2 inhibition

Patients diagnosed with localized high-risk prostate cancer have higher rates of recurrence, and the introduction of neoadjuvant intensive hormonal therapies seeks to treat occult micrometastatic disease by their addition to definitive treatment. Sufficient profiling of baseline disease has remained a challenge in enabling the in-depth assessment of phenotypes associated with exceptional vs. poor pathologic responses after treatment. In this study, we report comprehensive and integrative gene expression profiling of 37 locally advanced prostate tumors prior to six months of androgen deprivation therapy (ADT) plus the androgen receptor (AR) inhibitor enzalutamide prior to radical prostatectomy. A robust transcriptional program associated with HER2 activity was positively associated with poor outcome and opposed AR activity, even after adjusting for common genomic alterations in prostate cancer including PTEN loss and expression of the TMPRSS2:ERG fusion. Patients experiencing exceptional pathologic responses demonstrated lower levels of HER2 and phospho-HER2 by immunohistochemistry of biopsy tissues. The inverse correlation of AR and HER2 activity was found to be a universal feature of all aggressive prostate tumors, validated by transcriptional profiling an external cohort of 121 patients and immunostaining of tumors from 84 additional patients. Importantly, the AR activity-low, HER2 activity-high cells that resist ADT are a pre-existing subset of cells that can be targeted by HER2 inhibition alone or in combination with enzalutamide. In summary, we show that prostate tumors adopt an AR activity-low prior to antiandrogen exposure that can be exploited by treatment with HER2 inhibitors.

Molecular features of prostate cancer after neoadjuvant therapy in the phase 3 CALGB 90203 trial

BACKGROUND

The phase 3 CALGB 90203 (Alliance) trial evaluated neoadjuvant chemohormonal therapy for high-risk localized prostate cancer before radical prostatectomy. We dissected the molecular features of post-treated tumors with long-term clinical outcomes to explore mechanisms of response and resistance to chemohormonal therapy.

METHODS

We evaluated 471 radical prostatectomy tumors, including 294 samples from 166 patients treated with 6 cycles of docetaxel plus androgen deprivation therapy before radical prostatectomy and 177 samples from 97 patients in the control arm (radical prostatectomy alone). Targeted DNA sequencing and RNA expression of tumor foci and adjacent noncancer regions were analyzed in conjunction with pathologic changes and clinical outcomes.

RESULTS

Tumor fraction estimated from DNA sequencing was significantly lower in post-treated tumor tissues after chemohormonal therapy compared with controls. Higher tumor fraction after chemohormonal therapy was associated with aggressive pathologic features and poor outcomes, including prostate-specific antigen-progression-free survival. SPOP alterations were infrequently detected after chemohormonal therapy, while TP53 alterations were enriched and associated with shorter overall survival. Residual tumor fraction after chemohormonal therapy was linked to higher expression of androgen receptor-regulated genes, cell cycle genes, and neuroendocrine genes, suggesting persistent populations of active prostate cancer cells. Supervised clustering of post-treated high-tumor-fraction tissues identified a group of patients with elevated cell cycle-related gene expression and poor clinical outcomes.

CONCLUSIONS

Distinct recurrent prostate cancer genomic and transcriptomic features are observed after exposure to docetaxel and androgen deprivation therapy. Tumor fraction assessed by DNA sequencing quantifies pathologic response and could be a useful trial endpoint or prognostic biomarker. TP53 alterations and high cell cycle transcriptomic activity are linked to aggressive residual disease, despite potent chemohormonal therapy.

Surgical Management and Considerations for Patients with Localized High-Risk Prostate Cancer

OPINION STATEMENT

Localized high-risk (HR) prostate cancer (PCa) is a heterogenous disease state with a wide range of presentations and outcomes. Historically, non-surgical management with radiotherapy and androgen deprivation therapy was the treatment option of choice. However, surgical resection with radical prostatectomy (RP) and pelvic lymph node dissection (PLND) is increasingly utilized as a primary treatment modality for patients with HRPCa. Recent studies have demonstrated that surgery is an equivalent treatment option in select patients with the potential to avoid the side effects from androgen deprivation therapy and radiotherapy combined. Advances in imaging techniques and biomarkers have also improved staging and patient selection for surgical resection. Advances in robotic surgical technology grant surgeons various techniques to perform RP, even in patients with HR disease, which can reduce the morbidity of the procedure without sacrificing oncologic outcomes. Clinical trials are not only being performed to assess the safety and oncologic outcomes of these surgical techniques, but to also evaluate the role of surgical resection as a part of a multimodal treatment plan. Further research is needed to determine the ideal role of surgery to potentially provide a more personalized and tailored treatment plan for patients with localized HR PCa.

Novel Approaches in the Systemic Management of High-Risk Prostate Cancer

Locally advanced prostate cancer comprises approximately 20% of new prostate cancer diagnoses. For these patients, international guidelines recommend treatment with radiotherapy (RT) to the prostate in combination with long-term (2-3 years) androgen deprivation therapy (ADT), or radical prostatectomy in combination with extended pelvic lymph node dissection (PLND) as another treatment option for selected patients as part of multimodal therapy. Improvements in overall survival with docetaxel or an androgen receptor signaling inhibitor have been achieved in patients with metastatic castration sensitive or castration resistant prostate cancer. However, the role of systemic therapy combinations for high risk and/or unfavorable prostate cancer is unclear. In this context, the aim of this review is to assess the current evidence for systemic treatment combinations as part of primary definitive therapy in patients with high-risk localized prostate cancer.

Genitourinary cancer neoadjuvant therapies: current and future approaches

Neoadjuvant therapies can improve tolerability, reduce tumor volume to facilitate surgery, and assess subsequent treatment response. Therefore, there is much enthusiasm for expanding the benefits of cancer therapies to the neoadjuvant setting to reduce recurrence and improve survival in patients with localized or locally advanced genitourinary (GU) cancer. This approach is clinically pertinent because these treatments are administered primarily to treatment-naive patients and can elicit the greatest drug response. In addition, the results are not impacted by other anticancer treatments. While neoadjuvant therapies have been the standard treatment for bladder cancer in the past, they are presently restricted to clinical trials for renal and prostate cancer (PCa); however, changes are imminent. Precision neoadjuvant therapies will be ushered in by biomarker-stratified neoadjuvant trials with appropriate survival endpoints and comprehensive correlative and imaging studies. This review discusses neoadjuvant studies in GU malignancies and how they inform future study design considerations.

Mortality Risk for Docetaxel-Treated, High-Grade Prostate Cancer With Low PSA Levels: A Meta-Analysis

Importance

Patients with high-grade prostate cancer with low levels of prostate-specific antigen (PSA; <4 ng/mL) are at high risk of mortality, necessitating an improved treatment paradigm.

Objective

To assess for these patients whether adding docetaxel to standard of care (SOC) treatment is associated with decreased prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM).

Data Sources

PubMed search from 2000 to 2022.

Study Selection

Five prospective randomized clinical trials (RCTs) performed in the US, France, and the United Kingdom evaluating SOC treatment with radiotherapy and androgen deprivation therapy (ADT) or with radical prostatectomy vs SOC plus docetaxel.

Data Extraction and Synthesis

Individual data were included from patients with nonmetastatic prostate cancer, a PSA level of less than 4 ng/mL, and a Gleason score of 8 to 10. Patients initiated treatment between February 21, 2006, and December 31, 2015 (median follow-up, 7.1 [IQR, 5.4-9.9] years). Data were analyzed on December 16, 2022.

Main Outcomes and Measures

Hazard ratio (HR) of ACM and subdistribution HR (sHR) of PCSM adjusted for performance status (1 vs 0 or good health), Gleason score (9 or 10 vs 8), tumor category (T3-T4 vs T1-T2 or TX), and duration of ADT (2 years vs 4-6 months).

Results

From a cohort of 2184 patients, 145 patients (6.6%) in 4 RCTs were eligible (median age, 63 [IQR, 46-67] years). Thirty-one patients died, and of these deaths, 22 were due to prostate cancer. Performance status was 0 for 139 patients (95.9%) and 1 for 6 patients (4.1%). A reduced but nonsignificant risk of ACM (HR, 0.51 [95% CI, 0.24-1.09]) and PCSM (sHR, 0.42 [95% CI, 0.17-1.02]) was associated with patients randomized to SOC plus docetaxel compared with SOC. The risk reduction in ACM (HR, 0.46 [95% CI, 0.21-1.02]) was more pronounced among patients with a performance status of 0 and was significant for PCSM (sHR, 0.30 [95% CI, 0.11-0.86]).

Conclusions and Relevance

Adding docetaxel to SOC treatment for patients who are in otherwise good health with a PSA level of less than 4 ng/mL and a Gleason score of 8 to 10 was associated with a significant reduction in PCSM and therefore has the potential to improve prognosis.

Development and validation of a nomogram to predict cancer-specific survival in nonsurgically treated elderly patients with prostate cancer

Prostate Cancer (PC) is the most common male nonskin tumour in the world, and most diagnosed patients are over 65 years old. The main treatment for PC includes surgical treatment and nonsurgical treatment. Currently, for nonsurgically treated elderly patients, few studies have evaluated their prognostic factors. Our aim was to construct a nomogram that could predict cancer-specific survival (CSS) in nonsurgically treated elderly PC patients to assess their prognosis-related independent risk factors. Patient information was obtained from the Surveillance, Epidemiology and End Results (SEER) database, and our target population was nonsurgically treated PC patients who were over 65 years old. Independent risk factors were determined using both univariate and multivariate Cox regression models. A nomogram was built using a multivariate Cox regression model. The accuracy and discrimination of the prediction model were tested using the consistency index (C-index), the area under the subject operating characteristic curve (AUC), and the calibration curve. Decision curve analysis (DCA) was used to examine the potential clinical value of this model. A total of 87,831 elderly PC patients with nonsurgical treatment in 2010-2018 were included in the study and were randomly assigned to the training set (N = 61,595) and the validation set (N = 26,236). Univariate and multivariate Cox regression model analyses showed that age, race, marital status, TNM stage, chemotherapy, radiotherapy modality, PSA and GS were independent risk factors for predicting CSS in nonsurgically treated elderly PC patients. The C-index of the training set and the validation set was 0.894 (95% CI 0.888-0.900) and 0.897 (95% CI 0.887-0.907), respectively, indicating the good discrimination ability of the nomogram. The AUC and the calibration curves also show good accuracy and discriminability. We developed a new nomogram to predict CSS in elderly PC patients with nonsurgical treatment. The model is internally validated with good accuracy and reliability, as well as potential clinical value, and can be used for clinical aid in decision-making.

Surgery with or Without Darolutamide in High-risk and/or Locally Advanced Prostate Cancer: The SUGAR (CCAFU-PR2) Phase 2 Trial Rationale and Protocol

BACKGROUND

High-risk prostate cancer (PCa) patients frequently experience recurrence and progression after radical prostatectomy (RP). Neoadjuvant androgen deprivation therapy (ADT) has not demonstrated a clear oncological benefit and is not currently recommended.

OBJECTIVE

The SUGAR trial is the first phase 2, randomised, controlled, multicentre, noncommercial, open-label study investigating single-agent perioperative darolutamide compared with the standard of care (ie, upfront RP, without neoadjuvant ADT).

DESIGN, SETTING, AND PARTICIPANTS

SUGAR aims to randomise 240 men affected by nonmetastatic PCa, with the major eligibility criteria being International Society of Urological Pathology grade group ≥4, seminal vesicle invasion at magnetic resonance imaging and/or clinically node-positive disease. Patients in the experimental arm will undergo neoadjuvant darolutamide monotherapy, RP, and adjuvant darolutamide, completing 9 mo of treatment.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint is noncurable recurrence-free survival, an innovative and clinically meaningful measure; the secondary endpoints encompass safety; recurrence-free, metastasis-free, and overall survival; pathological response; and quality of life. A predictive biomarker analysis will also be performed.

RESULTS AND LIMITATIONS

Initial data suggest that intensified neoadjuvant treatment with androgen receptor signalling inhibitors (ARSIs) is associated with a sustained pathological response and may improve outcomes, via tumour downstaging and micrometastasis eradication. ARSI monotherapy could further enhance tolerability.

CONCLUSIONS

SUGAR will provide efficacy and safety information on perioperative darolutamide monotherapy compared with upfront RP, in a contemporary high-risk PCa population undergoing surgery.

PATIENT SUMMARY

The on-going SUGAR clinical trial evaluates 9 mo of darolutamide treatment in addition to radical prostatectomy, in men affected by prostate cancer with specific high-risk characteristics. It investigates whether this hormonal treatment can lower the rates of noncurable recurrences, maintaining a favourable tolerability profile.

Neoadjuvant Cabazitaxel plus Abiraterone/Leuprolide Acetate in Patients with High-Risk Prostate Cancer: ACDC-RP Phase II Trial

PURPOSE

Early treatment intensification with neoadjuvant therapy may improve outcomes in patients with high-risk, localized prostate cancer treated with radical prostatectomy. Our objective was to compare pathologic, oncologic, and safety outcomes of neoadjuvant abiraterone acetate plus leuprolide acetate with or without cabazitaxel prior to radical prostatectomy in patients with localized, high-risk prostate cancer.

PATIENTS AND METHODS

This open-label, multicenter, phase II trial randomized men with clinically localized, D'Amico high-risk prostate cancer to neoadjuvant abiraterone acetate (1,000 mg/day) and leuprolide acetate (22.5 mg every 3 months) with or without cabazitaxel (25 mg/m2) prior to radical prostatectomy. The primary outcome was pathologic complete response (pCR) or minimal residual disease (MRD). Secondary outcomes included surgical margins, lymph node involvement, pathologic stage, 12-month biochemical relapse-free survival (BRFS) rates, and safety profile.

RESULTS

The per-protocol population consisted of 70 patients [cabazitaxel arm (Arm A): 37, no cabazitaxel arm (Arm B): 33]. Median patient age and prostate-specific antigen levels were 63.5 years [interquartile range (IQR), 58.0-68.0] and 21.9 ng/mL (IQR, 14.6-42.8), respectively. pCR/MRD occurred in 16 (43.2%) versus 15 patients (45.5%) in arms A and B, respectively (P = 0.85). pCR occurred in two (5.4%) versus three patients (9.1%) in arms A and B, respectively (P = 0.66). Patients with ≤ 25% total biopsy cores positive had increased odds of pCR/MRD (P = 0.04). Patients with pCR/MRD had superior 12-month BRFS rates (96.0% vs. 62.0%, P = 0.03). Grade 3+ adverse events occurred in 42.5% and 23.7% of patients in arms A and B, respectively (P = 0.078).

CONCLUSIONS

Neoadjuvant cabazitaxel addition to abiraterone acetate/leuprolide acetate prior to radical prostatectomy did not improve pCR/MRD in clinically localized, high-risk prostate cancer.

Risk of Short-Term Prostate-Specific Antigen Recurrence and Failure in Patients With Prostate Cancer: A Secondary Analysis of a Randomized Clinical Trial

Importance

A shorter time interval to prostate-specific antigen (PSA) failure is associated with worse clinical outcomes; however, specific factors defining this state remain unknown.

Objective

To evaluate the factors of a short time interval to PSA failure in order to identify patients for treatment escalation randomized clinical trials.

Design, Setting, and Participants

This secondary analysis of a randomized clinical trial was a secondary analysis of the Dana-Farber Cancer Institute 05-043 trial and included 350 patients with nonmetastatic unfavorable risk prostate cancer (PC).

Interventions

Patients were randomized 1:1 to receive androgen deprivation therapy (ADT) and radiation therapy (RT) plus docetaxel vs ADT and RT.

Main Outcomes and Measures

Cumulative incidence rates curves of PSA failure, defined as PSA nadir plus 2 ng/mL or initiation of salvage therapies, and the Fine and Gray competing risks regression was used to assess the prognostic association between these factors and time to PSA failure.

Results

The study included 350 males who primarily had a good performance status (330 [94.3%] with Eastern Cooperative Oncology Group score of 0), median (range) age of 66 (43-86) years, with 167 (46.6%) having Gleason scores of 8 to 10, and 195 (55.2%) presenting with a baseline PSA of more than 10 ng/mL. After a median (IQR) follow-up of 10.2 (8.0-11.4) years, having a PSA level of 10 ng/mL to 20 ng/mL (subdistribution hazard ratio [sHR], 1.98; 95% CI, 1.28-3.07; P = .002) and a Gleason score of 8 to 10 (sHR, 2.55; 95% CI, 1.63-3.99; P < .001) were associated with a shorter time to PSA failure, and older age (sHR, 0.82; 95% CI, 0.72-0.93; P = .002) was associated with reduced risk for PSA failure after adjusting for other baseline clinical factors. The high-risk category, defined by these 3 factors, was associated with a shorter time to PSA failure (sHR, 2.69; 95% CI, 1.84-3.93; P < .001).

Conclusions and Relevance

In this secondary analysis of a randomized clinical trial of males with unfavorable risk PC, young age, PSA of 10 ng/mL or more, and a Gleason score of 8 to 10 estimated a shorter time to PSA failure. A subgroup of males at very high-risk for early PSA failure, as defined by our study, may benefit from treatment escalation with androgen receptor signaling inhibitors or cytotoxic chemotherapy and should be the subject of a prospective randomized clinical trial.

Trial Registration

NCT00116142.

Nomogram for predicting the biochemical recurrence of prostate cancer after neoadjuvant androgen deprivation therapy

BACKGROUND

A predictive model for biochemical recurrence (BCR) of prostate cancer (PCa) after neoadjuvant androgen deprivation therapy (nADT) has not been established. This study was aimed at determining multiparameter variables that could be used to construct a nomogram to predict the post-nADT BCR of PCa.

METHODS

Overall, 43 radical prostatectomy specimens from PCa patients who had undergone nADT were collected. Multiparameter variables were analyzed by univariate and then multivariate logistic analyses to identify the independent prognostic factors for predicting BCR. The predictive model was established using Lasso regression analysis.

RESULTS

Univariate logistic analysis revealed six variables, pathology stage; margins; categorization as group A, B, or C; nucleolus grading; percentage of tumor involvement (PTI); and PTEN status were significantly associated with the BCR of PCa (all p < 0.05). Multivariate logistic regression analysis suggested that categorization as group C, severe nucleolus grading, PTI less than or equal to 5%, and PTEN loss were positively correlated with BCR (all p < 0.05). A nomogram comprising the four variables predicting BCR was constructed, and it exhibited good discrimination (AUC: 0.985; specificity: 86.2%; sensitivity: 100%). Calibration plots for the probability of freedom from BCR at 1 and 2 years showed a good match between the prediction by the nomogram.

CONCLUSIONS

We constructed and validated a nomogram to predict the risk of BCR in PCa patients after nADT. This nomogram is a complement to the existing risk stratification systems for PCa, which could have marked implications for clinical decision-making for PCa patients after nADT.

Androgen Deprivation and Radiotherapy with or Without Docetaxel for Localized High-risk Prostate Cancer: Long-term Follow-up from the Randomized NRG Oncology RTOG 0521 Trial

BACKGROUND

Intensification of therapy may improve outcomes for patients with high-risk localized prostate cancer.

OBJECTIVE

To provide long-term follow-up data from phase III RTOG 0521, which compared a combination of androgen deprivation therapy (ADT) + external beam radiation therapy (EBRT) + docetaxel with ADT + EBRT.

DESIGN, SETTING, AND PARTICIPANTS

High-risk localized prostate cancer patients (>50% of patients had Gleason 9-10 disease) were prospectively randomized to 2 yr of ADT + EBRT or ADT + EBRT + six cycles of docetaxel. A total of 612 patients were accrued, and 563 were eligible and included in the modified intent-to-treat analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was overall survival (OS). Analyses with Cox proportional hazards were performed as prespecified in the protocol; however, there was evidence of nonproportional hazards. Thus, a post hoc analysis was performed using the restricted mean survival time (RMST). The secondary endpoints included biochemical failure, distant metastasis (DM) as detected by conventional imaging, and disease-free survival (DFS).

RESULTS AND LIMITATIONS

After 10.4 yr of median follow-up among survivors, the hazard ratio (HR) for OS was 0.89 (90% confidence interval [CI] 0.70-1.14; one-sided log-rank p = 0.22). Survival at 10 yr was 64% for ADT + EBRT and 69% for ADT + EBRT + docetaxel. The RMST at 12 yr was 0.45 yr and not statistically significant (one-sided p = 0.053). No differences were detected in the incidence of DFS (HR = 0.92, 95% CI 0.73-1.14), DM (HR = 0.84, 95% CI 0.73-1.14), or prostate-specific antigen recurrence risk (HR = 0.97, 95% CI 0.74-1.29). Two patients had grade 5 toxicity in the chemotherapy arm and zero patients in the control arm.

CONCLUSIONS

After a median follow-up of 10.4 yr among surviving patients, no significant differences are observed in clinical outcomes between the experimental and control arms. These data suggest that docetaxel should not be used for high-risk localized prostate cancer. Additional research may be warranted using novel predictive biomarkers.

PATIENT SUMMARY

No significant differences in survival were noted after long-term follow-up for high-risk localized prostate cancer patients in a large prospective trial where patients were treated with androgen deprivation therapy + radiation to the prostate ± docetaxel.

Androgen deprivation therapy plus abiraterone or docetaxel as neoadjuvant therapy for very-high-risk prostate cancer: a pooled analysis of two phase II trials

Objective: The study aimed to compare the efficacy and safety of androgen deprivation therapy (ADT) with abiraterone or docetaxel versus ADT alone as neoadjuvant therapy in patients with very-high-risk localized prostate cancer. Methods: This was a pooled analysis of two single-center, randomized, controlled, phase II clinical trials (ClinicalTrials.gov: NCT04356430 and NCT04869371) conducted from December 2018 to March 2021. Eligible participants were randomly assigned to the intervention (ADT plus abiraterone or docetaxel) and control (ADT alone) groups at a 2:1 ratio. Efficacy was evaluated by pathological complete response (pCR), minimal residual disease (MRD), and 3-year biochemical progression-free survival (bPFS). Safety was also analyzed. Results: The study included 42 participants in the ADT group, 47 in the ADT plus docetaxel group, and 48 in the ADT plus abiraterone group. A total of 132 (96.4%) participants had very-high-risk prostate cancer, and 108 (78.8%) had locally advanced disease. The ADT plus docetaxel group (28%) and ADT plus abiraterone group (31%) had higher rates of pCR or MRD (p = 0.001 and p < 0.001) compared with the ADT group (2%). The 3-year bPFS was 41.9% (95% CI: 26.6-57.2), 51.1% (95% CI: 36.8-65.4), and 61.2% (95% CI: 45.5-76.9), respectively. Significant difference was found among groups in terms of bPFS (p = 0.037). Conclusion: Compared with ADT alone, neoadjuvant therapy with ADT plus docetaxel or abiraterone could achieve better pathological outcomes (pCR or MRD) for very-high-risk localized prostate cancer. The ADT plus abiraterone group showed longer bPFS than ADT alone. The combination regimens were tolerable.

Predictive factors associated with differential pathologic response to neoadjuvant chemohormonal therapy in high-risk localized prostate cancer

PURPOSE

To explore the clinical parameters and molecular biomarkers that can predict differential pathologic response to neoadjuvant chemohormonal therapy (NCHT) in prostate cancer (CaP).

METHODS

A total of 128 patients with primary high-risk localized CaP who had received NCHT followed by radical prostatectomy (RP) were included. Androgen receptor (AR), AR splice variant-7 (AR-V7) and Ki-67 staining were evaluated in prostate biopsy specimens by immunohistochemistry. The pathologic response to NCHT in whole mount RP specimens was measured based on the reduction degree of tumor volume and cellularity compared to the paired pretreatment needle biopsy, and divided into 5 tier grades (Grades 0-4). Patients with Grades 2 to 4 (the reduction degree more than 30%) were defined as having a favorable response. Logistic regression was performed to explore the predictive factors associated with a favorable pathologic response. The predictive accuracy was evaluated by receiver operating characteristic (ROC) curve and area under the ROC curve (AUC).

RESULTS

Ninety-seven patients (75.78%) had a favorable response to NCHT. Logistic regression showed that the preoperative PSA level, low AR expression and high Ki-67 expression in biopsy specimens were associated with a favorable pathologic response (P < 0.05). Furthermore, the AUC of the preoperative PSA level, AR and Ki-67 were 0.625, 0.624 and 0.723, respectively. Subgroup analysis revealed that the rate of favorable pathologic response to NCHT was 88.5% in patients with AR^lowKi-67^high, which was higher than patients with AR^lowKi-67^low, AR^highKi-67^low, and AR^highKi-67^high (88.5% vs. 73.9%, 72.9%, and 70.9%, all P < 0.05).

CONCLUSIONS

A lower preoperative PSA level was an independent predictive factor for a favorable pathologic response. Moreover, the expression status of AR and Ki-67 in biopsy specimens were associated with differential pathologic response to NCHT, and AR low/Ki-67 high was also associated with favorable response but warrants further evaluation in this patient subgroup and future trial clinical trial design.

Transcriptomic signature defines two subtypes of locally advanced PCa with distinct neoadjuvant therapy benefits

Background

Patients with locally advanced prostate cancer (LAPCa) received docetaxel-based neoadjuvant chemo-hormonal therapy (NCHT) had better clinical outcomes after surgery compared to neoadjuvant hormonal therapy (NHT) groups, but not all patients experienced favorable clinical outcomes with NCHT, raising the necessity for potential biomarker assessment. The transcriptomic profiling offers a unique opportunity to interrogate the accurate response to NCHT and NHT treatment and to identify the predictive biomarkers for neoadjuvant therapy.

Methods

The whole transcriptomic profiling was performed on baseline biopsies and surgical tissue specimens from 64 patients with LAPCa at Renji Hospital between 2014 and 2018. Biochemical progression-free survival (bPFS)-based gene-by-treatment interaction effects were used to identify predictive biomarkers for guiding treatment selection.

Results

Comparing the transcriptome profiling of pre- and post-treatment LAPCa specimens, NHT and NCHT shared 1917 up- and 670 down-regulated DEGs at least 2-fold. Pathway enrichment analysis showed up-regulated pathways in response to NHT and NCHT were both enriched in cytokine receptor interaction pathways, and down-regulated pathways in response to NCHT were enriched in cell cycle pathways. By comprehensive transcriptome profiling of 64 baseline specimens, ten predictive markers were identified. We integrated them into the signature to evaluate the relative benefits of neoadjuvant therapy, which categorizes patients into two subgroups with relative bPFS benefits from either NHCT or NHT. In the high-score (≥ -95.798) group (n = 37), NCHT treatment led to significantly longer bPFS (P< 0.0001), with a clear and early separation of the Kaplan-Meier curves. In the low-score (< -95.798) group (n = 27), NHT also led to significantly longer bPFS (P=0.0025).

Conclusions

In this study, we proposed the first predictive transcriptomic signature might potentially guide the effective selection of neoadjuvant therapy in LAPCa and might provide precise guidance toward future personalized adjuvant therapy.

Trial registration

The study was approved by the Ethics Committee of Renji Hospital affiliated to Shanghai Jiao Tong University (Ky2019-087).

Neoadjuvant Androgen Receptor Signaling Inhibitors before Radical Prostatectomy for Non-Metastatic Advanced Prostate Cancer: A Systematic Review

(1) Background: Several phase II studies, including randomized controlled trials (RCTs), assessed the efficacy of adding androgen receptor signaling inhibitors (ARSIs) to androgen deprivation therapy (ADT) as a neoadjuvant treatment in patients treated with radical prostatectomy (RP) for prostate cancer (PCa). Summarizing the early results of these studies could help in designing phase III trials and patient counseling. (2) Methods: We queried three databases in January 2023 for studies that included PCa patients treated with neoadjuvant ARSI-based combination therapy before RP. The outcomes of interest were oncologic outcomes and pathologic responses, such as pathologic complete response (pCR) and minimal residual disease (MRD). (3) Results: Overall, twenty studies (eight RCTs) were included in this systematic review. Compared to ADT or ARSI alone, ARSI + ADT was associated with higher pCR and MRD rates; this effect was less evident when adding a second ARSI or chemotherapy. Nevertheless, ARSI + ADT resulted in relatively low pCR rates (0-13%) with a high proportion of ypT3 (48-90%) in the resected specimen. PTEN loss, ERG positive, or intraductal carcinoma seem to be associated with worse pathologic response. One study that adjusted for the effects of possible confounders reported that neoadjuvant ARSI + ADT improved time to biochemical recurrence and metastasis-free survival compared to RP alone. (4) Conclusions: Neoadjuvant ARSI + ADT combination therapy results in improved pathologic response compared to either alone or none in patients with non-metastatic advanced PCa. Ongoing phase III RCTs with long-term oncologic outcomes, as well as biomarker-guided studies, will clarify the indication, oncologic benefits, and adverse events of ARSI + ADT in patients with clinically and biologically aggressive PCa.

Head-to-head comparisons of [68Ga]Ga-PSMA-11 PET/CT, multiparametric MRI, and prostate-specific antigen for the evaluation of therapeutic responses to neoadjuvant chemohormonal therapy in high-risk non-metastatic prostate cancer patients: a prospective study

PURPOSE

The optimal tool to evaluate the tumour therapeutic responses to neoadjuvant chemohormonal therapy (NCHT) in patients with high-risk non-metastatic prostate cancer (PCa) remains uncertain. We compared the role of [⁶⁸Ga]-labeled prostate-specific membrane antigen (PSMA)-11 positron emission tomography/computerized tomography ([⁶⁸Ga]Ga-PSMA-11 PET/CT), multiparametric MRI (mpMRI), and prostate-specific antigen (PSA) and assessed the practical value of the recent European Association of Urology and European Association of Nuclear Medicine (EAU/EANM) recommended criteria of PSMA PET/CT to evaluate the therapeutic responses to NCHT in patients with high-risk non-metastatic PCa.

METHODS

This prospective study included 72 high-risk non-metastatic PCa patients receiving NCHT followed by radical prostatectomy from June 2021 to March 2022. PSA testing, [⁶⁸Ga]Ga-PSMA-11 PET/CT, and mpMRI scanning were conducted in all patients before and after NCHT. Therapeutic responses to NCHT were evaluated with PSA, RECIST 1.1, PERCIST 1.0, and EAU/EANM recommended criteria. Postoperative pathological results were considered the reference standard. A favourable pathological response was defined as pathologic complete remission (pCR) or minimal residual disease (MRD). Diagnostic accuracy was assessed by sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), positive predictive value (PPV), negative predictive value (NPV), and Cohen's kappa index. Logistic regression analysis was used to determine the independent predictive value of [⁶⁸Ga]Ga-PSMA-11 PET/CT-derived parameters.

RESULTS

All cases experienced a marked decrease in PSA levels after NCHT. Twenty-four (33.33%) cases experienced a favourable pathological response, including five (6.94%) cases of pCR and 19 (26.39%) cases of MRD. According to the results of [⁶⁸Ga]Ga-PSMA-11 PET/CT, EAU/EANM recommended criteria indicated that 20 (27.78%) cases had a CR, whereas PERCIST 1.0 criteria indicated that 23 (31.94%) cases had a CR. There was a strong association between EAU/EANM recommended criteria and PERCIST 1.0 criteria (Pearson's R=0.857). The sensitivity (75.00%, 79.17% vs. 58.33%, 58.33%), specificity (95.83%, 91.67% vs. 83.33%, 68.75%), PLR (18.00, 9.50 vs. 3.50, 1.87), NLR (0.26, 0.23 vs. 0.50, 0.61), PPV (90.0%, 82.6% vs. 63.6%, 48.3%), and NPV (88.5%, 89.8% vs. 80.0%, 76.7%) of [⁶⁸Ga]Ga-PSMA-11 PET/CT (including EAU/EANM recommended criteria and PERCIST 1.0 criteria) to predict favourable pathological responses were all superior to those of mpMRI and nadir PSA. The kappa index to predict a favourable pathological response was 0.257 for PSA, 0.426 for RECIST 1.1, 0.716 for PERCIST 1.0, and 0.739 for EAU/EANM recommended criteria. Multivariate logistic analysis revealed that the post-NCHT maximum standardized uptake value (SUVmax) before radical prostatectomy was an independent predictor of a favourable pathological response to NCHT.

CONCLUSIONS

[⁶⁸Ga]Ga-PSMA-11 PET/CT had a better concordance with a favourable pathological response to NCHT compared with nadir PSA and mpMRI. EAU/EANM recommended criteria and PERCIST 1.0 criteria performed equally to identify pathological responders when [⁶⁸Ga]Ga-PSMA-11 PET/CT was used as a therapeutic response assessment tool.

Personalized downstaging treatment with ADT, chemotherapy and add-on zimberelimab for very-high-risk clinically localized prostate cancer: A case report

RATIONALE

Very-high-risk prostate cancer (PCa) is associated with poor prognosis. Radical prostatectomy (RP) is an option for selected high-risk PCa cases, especially in younger, healthier patients. However, a high Gleason score and high T stage can increase the risk of RP. Neoadjuvant therapy has been reported in high- or very-high-risk PCa, but its clinical use remains controversial.

DIAGNOSES AND PATIENT CONCERNS

A 53-year-old male patient diagnosed with PCa was referred to our hospital. The patient's Gleason score was 4 + 5, and the clinical stage was T4N0M0, with an abnormally enlarged prostate adhering to the rectum and leading to decreased mobility of the rectum, suggesting a very-high-risk PCa inappropriate for RP. However, instead of external beam radiation therapy, which is the standard treatment for inoperable PCa, the patient insisted on RP.

INTERVENTIONS

Androgen deprivation therapy plus docetaxel was chosen as the first downstaging treatment; however, the tumor was too slightly downsized to undergo RP. Therefore, zimberelimab was added after confirmation of a genomic feature of high microsatellite instability and high tumor mutational burden status.

OUTCOMES

After 4 doses of zimberelimab, the prostate shrank significantly. The patient successfully completed RP after another dose of zimberelimab, and achieved a pathological complete response (pCR).

LESSONS

Our case represents a successful attempt at personalized treatment and provides preliminary evidence for the clinical use of downstaging therapy of androgen deprivation therapy, chemotherapy, and add-on zimberelimab for very-high-risk clinically localized PCa.

A Phase I Trial of Neoadjuvant Stereotactic Body Radiotherapy Prior to Radical Prostatectomy for Locally Advanced Prostate Cancer

PURPOSE

Men with locally advanced prostate cancer who undergo radical prostatectomy (RP) often develop recurrence and require postoperative radiotherapy. We aimed to determine the safety of neoadjuvant stereotactic body radiotherapy (SBRT) before RP in this population.

METHODS AND PATIENTS

A single-institution phase 1 trial (NCT02946008) of men with high-risk or node-positive prostate cancer were enrolled between March and October 2017. The primary endpoint was to determine the maximum tolerated dose of SBRT based on a composite 30-day post-RP toxicity goal of ≤28% of patients experiencing a dose-limiting toxicity (DLT). Secondary outcomes included toxicity, efficacy, and multiple quality of life (QoL) inventories. SBRT (30-35 Gy/5 fractions) was delivered to the prostate and seminal vesicles, and 25 Gy/5 fractions to the pelvic lymph nodes. RP was performed for a median of 6 weeks post-SBRT. Hormone therapy was not allowed.

RESULTS

Median follow-up was 40 months (range, 33-44). Twenty-five percent of the patients (n = 4) experienced a DLT within 30 days post-RP; however, the trial was stopped early (n = 16 of planned 38 patients) owing to the proportion and severity of the late adverse events. Post-RP grade 3 genitourinary and gastrointestinal toxicities occurred in 75% (n = 12) and 25% (n = 4) of patients, respectively. Two patients required cystectomy and urinary diversion ≥2 years post-RP. At 24 months post-RP, 75% (n = 12) of men used ≥1 pad/d and 0% had erections suitable for intercourse. Surgical margins were negative in all patients and 31% (n = 5) had complete or partial (pre-RP) MRI-response to SBRT. Three-year biochemical recurrence and distant metastasis were 45% (95% CI, 5%-68%) and 28% (95% CI, 0%-49%), respectively.

CONCLUSIONS

Neoadjuvant SBRT followed by RP resulted in unacceptably high toxicity and severe QoL declines.

Neoadjuvant 177Lu-PSMA-I&T Radionuclide Treatment in Patients with High-risk Prostate Cancer Before Radical Prostatectomy: A Single-arm Phase 1 Trial

BACKGROUND

High-risk localized prostate cancer (HRLPC) has a substantial risk of disease progression despite local treatment. Neoadjuvant systemic therapy before definitive local therapy may improve oncological outcomes by targeting the primary tumor and micrometastatic disease.

OBJECTIVE

To evaluate whether a lutetium-177 prostate-specific membrane antigen radioligand (LuPSMA) can be safely administered to patients with HRLPC before robot-assisted radical prostatectomy (RARP) and to describe immediate oncological outcomes.

DESIGN, SETTING, AND PARTICIPANTS

This was an open-label, single-arm clinical trial. Patients with HRLPC and elevated radioligand uptake on PSMA positron emission tomography/computed tomography were enrolled. Two or three LuPSMA radioligand doses (7.4 GBq) were given at 2-wk intervals. RARP with lymph node dissection was performed 4 wk after the last LuPSMA dose.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The rate of surgical complications, operative parameters, changes in functional and quality-of-life measures, and immediate oncological outcomes (histological findings and biochemical response) were measured. Data were analyzed descriptively.

RESULTS AND LIMITATIONS

Fourteen patients participated (median age 67 yr). Prostate-specific antigen decreased by 17% (interquartile range [IQR] 9-50%) after two LuPSMA doses and 34% (IQR 11-60%) after three doses. Thirteen patients underwent RARP with no identifiable anatomical changes or intraoperative complications. Four patients (30%) had postoperative complications (pneumonia, pulmonary embolism, urinary leak with urinary tract infection). At 3 mo postoperatively, 12 patients (92%) required one pad or less. Final whole-mount pathology showed positive surgical margins (PSMs) in seven patients (53%) and downgrading to International Society of Urological Pathology grade group 3 in three patients (23%). Treatment-related effects included a clear vacuolated cytoplasm and pyknotic nuclei.

CONCLUSIONS

LuPSMA followed by RARP appears to be surgically safe. While oncological outcomes are pending, continence recovery seems to be unaffected by LuPSMA treatment.

PATIENT SUMMARY

We evaluated outcomes for patients with aggressive localized prostate cancer who received treatment with a radioactive agent before surgical removal of their prostate. This approach appears to be safe and feasible, but its therapeutic efficacy is still unknown.

Genitourinary tumors

Memorial Sloan Kettering Cancer Center (MSK) has made many notable contributions to the scientific understanding and care of patients with common urologic cancers. Many of the advances represented paradigm shifts in management and established new standards of care. This review highlights the surgical procedures and treatment strategies originated and pioneered by urologic surgeons and colleagues at MSK during the past 50 years.

ARNEO: A Randomized Phase II Trial of Neoadjuvant Degarelix with or Without Apalutamide Prior to Radical Prostatectomy for High-risk Prostate Cancer

BACKGROUND

High-risk prostate cancer (PCa) patients have a high risk of biochemical recurrence and metastatic progression following radical prostatectomy (RP).

OBJECTIVE

To determine the efficacy of neoadjuvant degarelix plus apalutamide before RP compared with degarelix with a matching placebo.

DESIGN, SETTING, AND PARTICIPANTS

ARNEO was a randomized, placebo-controlled, phase II neoadjuvant trial before RP performed between March 2019 and April 2021. Eligible patients had high-risk PCa and were amenable to RP.

INTERVENTION

Patients were randomly assigned at a 1:1 ratio to degarelix (240-80-80 mg) + apalutamide (240 mg/d) versus degarelix + matching placebo for 3 mo followed by RP. Prior to and following neoadjuvant treatment, pelvic ¹⁸F-PSMA-1007 positron emission tomography (PET)/magnetic resonance imaging (MRI) was performed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the difference in proportions of patients with minimal residual disease (MRD; = residual cancer burden (RCB) ≤0.25 cm³ at final pathology). Secondary endpoints included differences in prostate-specific antigen responses, pathological staging, and change in TNM stage on prostate-specific membrane antigen (PSMA) PET/MRI following hormonal treatment. Biomarkers (immunohistochemical staining on prostate biopsy [PTEN, ERG, Ki67, P53, GR, and PSMA] and PSMA PET/MRI-derived characteristics) associated with pathological response (MRD and RCB) were explored.

RESULTS AND LIMITATIONS

Patients were randomized to neoadjuvant degarelix + apalutamide (n = 45) or degarelix + matching placebo (n = 44) for 12 wk and underwent RP. Patients in the degarelix + apalutamide arm achieved a significantly higher rate of MRD than those in the control arm (38% vs 9.1%; relative risk [95% confidence interval] = 4.2 [1.5-11], p = 0.002). Patients with PTEN loss in baseline prostate biopsy attained significantly less MRD (11% vs 43%, p = 0.002) and had a higher RCB at final pathology (1.6 vs 0.40 cm³, p < 0.0001) than patients without PTEN loss. Following neoadjuvant hormonal therapy, PSMA PET-estimated tumor volumes (1.2 vs 2.5 ml, p = 0.01) and maximum standardized uptake value (SUVmax; 4.3 vs 5.7, p = 0.007) were lower in patients with MRD than in patients without MRD. PSMA PET-estimated volume and PSMA PET SUVmax following neoadjuvant treatment correlated significantly with RCB at final pathology (both p < 0.001).

CONCLUSIONS

In high-risk PCa patients, neoadjuvant degarelix plus apalutamide prior to RP results in a significantly improved pathological response (MRD and RCB) compared with degarelix alone. Our trial results provide a solid hypothesis-generating basis for neoadjuvant phase 3 trials, which are powered to detect differences in long-term oncological outcome following neoadjuvant androgen receptor signaling inhibitor therapy.

PATIENT SUMMARY

In this study, we looked at the difference in pathological responses in high-risk prostate cancer patients treated with degarelix plus apalutamide or degarelix plus matching placebo prior to radical prostatectomy. We demonstrated that patients treated with degarelix plus apalutamide achieved a significantly better tumor response than patients treated with degarelix plus matching placebo. Long-term follow-up is required to determine whether improved pathological outcome translates into better oncological outcomes.

Neoadjuvant Chemohormonal Therapy in Prostate Cancer Before Radical Prostatectomy: A Systematic Review and Meta-Analysis

Objective

This meta-analysis was to investigate the effects of neoadjuvant chemohormonal therapy (NCHT) on patients with prostate cancer (PCa) before radical prostatectomy (RP) and attempt to provide meaningful evidence.

Methods

A systematic search was performed using the PubMed, Web of Science, and Cochrane Library databases in February 2022 based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The relevant studies were critically screened and we extracted the data of demography, postoperative pathology, and survival to calculate the pooled effect sizes. Subgroup analyses and sensitivity analyses were used to explore the source of heterogeneity.

Results

Six identified studies involving 1717 subjects were included according to the selection criteria. There was no significant difference between NCHT plus RP and RP alone groups regarding lymph node involvement (risk ratio [RR]=1.03, 95% confidence interval [CI]: 0.57-1.87, P=0.92). However, NCHT prior to RP significantly decreased the rates of positive surgical margin (PSM, RR=0.35, 95% CI: 0.22-0.55, P<0.0001) and seminal vesicle invasion (SVI, RR=0.78, 95% CI: 0.65-0.95, P=0.01), and increase pathological downstaging (RR=1.64, 95% CI: 1.17-2.29, P=0.004). Additionally, biochemical recurrence-free survival (BRFS) and overall survival (OS) were significantly prolonged under the administration of NCHT (HR=0.54, 95% CI: 0.34-0.85, P=0.008 and HR=0.67, 95% CI: 0.48-0.94, P=0.02, respectively).

Conclusions

Compared to the RP alone group, patients with NCHT plus RP showed significant improvements in PSM, SVI, pathological downstaging, BRFS, and OS, whereas further multicenter randomized controlled trials are needed to consolidate this concept.

Clinical Benefit Scales and Trial Design: Some Statistical Issues

Recently developed clinical-benefit outcome scales by the European Society for Medical Oncology (ESMO) and the American Society of Clinical Oncology (ASCO) allow standardized objective evaluation of outcomes of randomized clinical trials. However, incorporation of clinical-benefit outcome scales into trial designs highlights a number of statistical issues: the relationship between minimal clinical benefit and the target treatment-effect alternative used in the trial design, designing trials to assess long-term benefit, potential problems with using a trial endpoint that is not overall survival, and how to incorporate subgroup analyses into the trial design. Using the ESMO Magnitude of Clinical Benefit Scale as a basis for discussion, we review what these issues are and how they can guide the choice of trial-design target effects, appropriate endpoints, and pre-specified subgroup analyses to increase the chances that the resulting trial outcomes can be appropriately evaluated for clinical benefit.

PSMA PET/CT guided intensification of therapy in patients at risk of advanced prostate cancer (PATRON): a pragmatic phase III randomized controlled trial

BACKGROUND

Positron emission tomography targeting the prostate specific membrane antigen (PSMA PET/CT) has demonstrated unparalleled performance as a staging examination for prostate cancer resulting in substantial changes in management. However, the impact of altered management on patient outcomes is largely unknown. This study aims to assess the impact of intensified radiotherapy or surgery guided by PSMA PET/CT in patients at risk of advanced prostate cancer.

METHODS

This pan-Canadian phase III randomized controlled trial will enroll 776 men with either untreated high risk prostate cancer (CAPRA score 6-10 or stage cN1) or biochemically recurrent prostate cancer post radical prostatectomy (PSA > 0.1 ng/mL). Patients will be randomized 1:1 to either receive conventional imaging or conventional plus PSMA PET imaging, with intensification of radiotherapy or surgery to newly identified disease sites. The primary endpoint is failure free survival at 5 years. Secondary endpoints include rates of adverse events, time to next-line therapy, as well as impact on health-related quality of life and cost effectiveness as measured by incremental cost per Quality Adjusted Life Years gained.

DISCUSSION

This study will help create level 1 evidence needed to demonstrate whether or not intensification of radiotherapy or surgery based on PSMA PET findings improves outcomes of patients at risk of advanced prostate cancer in a manner that is cost-effective.

TRIAL REGISTRATION

This trial was prospectively registered in ClinicalTrials.gov as NCT04557501 on September 21, 2020.

Biomarkers of Response to Neoadjuvant Androgen Deprivation in Localised Prostate Cancer

Simple Summary

Prostate cancer is the second leading cause of cancer deaths in men. Attempts to improve patient outcomes include trials of neoadjuvant androgen deprivation therapy for patients with high-risk disease. Neoadjuvant treatment refers to androgen deprivation therapy that is administered prior to surgery (or radiation therapy). Patients typically respond well to this treatment regimen, showing a decrease in tumour size, but a significant proportion of patients eventually relapse and progress to metastatic disease. The mechanisms driving this resistance to neoadjuvant treatment are currently unknown. This review explores theories of resistance broadly, and their possible applications in the prostate cancer setting. Additionally, this review draws comparisons between breakthrough resistance and neoadjuvant resistance, and lastly investigates the current biomarkers for treatment sensitivity.

Abstract

Prostate cancer (PCa) is a hormone driven cancer, characterised by defects in androgen receptor signalling which drive the disease process. As such, androgen targeted therapies have been the mainstay for PCa treatment for over 70 years. High-risk PCa presents unique therapeutic challenges, namely in minimising the primary tumour, and eliminating any undetected micro metastases. Trials of neoadjuvant androgen deprivation therapy aim to address these challenges. Patients typically respond well to neoadjuvant treatment, showing regression of the primary tumour and negative surgical margins at the time of resection, however the majority of patients relapse and progress to metastatic disease. The mechanisms affording this resistance are largely unknown. This commentary attempts to explore theories of resistance more broadly, namely, clonal evolution, cancer stem cells, cell persistence, and drug tolerance. Moreover, it aims to explore the application of these theories in the PCa setting. This commentary also highlights the distinction between castration resistant PCa, and neoadjuvant resistant disease, and identifies the markers and characteristics of neoadjuvant resistant disease presented by current literature.

Neoadjuvant hormonal therapy before radical prostatectomy in high-risk prostate cancer

Patients with high-risk prostate cancer treated with curative intent are at an increased risk of biochemical recurrence, metastatic progression and cancer-related death compared with patients treated for low-risk or intermediate-risk disease. Thus, these patients often need multimodal therapy to achieve complete disease control. Over the past two decades, multiple studies on the use of neoadjuvant treatment have been performed using conventional androgen deprivation therapy, which comprises luteinizing hormone-releasing hormone agonists or antagonists and/or first-line anti-androgens. However, despite results from these studies demonstrating a reduction in positive surgical margins and tumour volume, no benefit has been observed in hard oncological end points, such as cancer-related death. The introduction of potent androgen receptor signalling inhibitors (ARSIs), such as abiraterone, apalutamide, enzalutamide and darolutamide, has led to a renewed interest in using neoadjuvant hormonal treatment in high-risk prostate cancer. The addition of ARSIs to androgen deprivation therapy has demonstrated substantial survival benefits in the metastatic castration-resistant, non-metastatic castration-resistant and metastatic hormone-sensitive settings. Intuitively, a similar survival effect can be expected when applying ARSIs as a neoadjuvant strategy in high-risk prostate cancer. Most studies on neoadjuvant ARSIs use a pathological end point as a surrogate for long-term oncological outcome. However, no consensus yet exists regarding the ideal definition of pathological response following neoadjuvant hormonal therapy and pathologists might encounter difficulties in determining pathological response in hormonally treated prostate specimens. The neoadjuvant setting also provides opportunities to gain insight into resistance mechanisms against neoadjuvant hormonal therapy and, consequently, to guide personalized therapy.

Dual-Tracer Positron-Emission Tomography Using Prostate-Specific Membrane Antigen and Fluorodeoxyglucose for Staging of Prostate Cancer: A Systematic Review

PSMA PET is more accurate than conventional imaging (CT/bone scan) for staging of intermediate- or high-risk prostate cancer (PCa), but 5–10% of primary tumours have low PSMA ligand uptake. FDG PET has been used to further define disease extent in end-stage castrate-resistant PCa and may be beneficial earlier in the disease course for more accurate staging. The objective of this study was to review the available evidence for patients undergoing both FDG and PSMA PET for PCa staging at initial diagnosis and in recurrent disease. A systematic literature review was performed for studies with direct, intraindividual comparison of PSMA and FDG PET for staging of PCa. Assessment for radioligand therapy eligibility was not considered. Risk of bias was assessed. 543 citations were screened and assessed. 13 case reports, three retrospective studies, and one prospective study were included. FDG after PSMA PET improved the detection of metastases from 65% to 73% in high-risk early castration-resistant PCa with negative conventional imaging (M0). Positive FDG PET was found in 17% of men with negative PSMA PET for postprostatectomy biochemical recurrence. Gleason score ≥8 and higher PSA levels predicted FDG-avid metastases in BCR and primary staging. Variant histology (ductal and neuroendocrine) was common in case reports, resulting in PSMA-negative FDG-positive imaging for 3 patients. Dual-tracer PET for PCa may assist in characterising high-risk disease during primary staging and restaging. Further studies are required to determine the additive benefit of FDG PET and if the FDG-positive phenotype may indicate a poorer prognosis.

Results of a Randomized Phase II Trial of Intense Androgen Deprivation Therapy prior to Radical Prostatectomy in Men with High-Risk Localized Prostate Cancer

PURPOSE

This multicenter randomized phase 2 trial investigates the impact of intense androgen deprivation on radical prostatectomy pathologic response and radiographic and tissue biomarkers in localized prostate cancer (NCT02903368).

MATERIALS AND METHODS

Eligible patients had a Gleason score ≥4+3=7, prostate specific antigen >20 ng/mL or T3 disease and lymph nodes <20 mm. In Part 1, patients were randomized 1:1 to apalutamide, abiraterone acetate, prednisone and leuprolide (AAPL) or abiraterone, prednisone, leuprolide (APL) for 6 cycles (1 cycle=28 days) followed by radical prostatectomy. Surgical specimens underwent central review. The primary end point was the rate of pathologic complete response or minimum residual disease (minimum residual disease, tumor ≤5 mm). Secondary end points included prostate specific antigen response, positive margin rate and safety. Magnetic resonance imaging and tissue biomarkers of pathologic outcomes were explored.

RESULTS

The study enrolled 118 patients at 4 sites. Median age was 61 years and 94% of patients had high-risk disease. The combined pathologic complete response or minimum residual disease rate was 22% in the AAPL arm and 20% in the APL arm (difference: 1.5%; 1-sided 95% CI -11%, 14%; 1-sided p=0.4). No new safety signals were observed. There was low concordance and correlation between posttherapy magnetic resonance imaging assessed and pathologically assessed tumor volume. PTEN-loss, ERG positivity and presence of intraductal carcinoma were associated with extensive residual tumor.

CONCLUSIONS

Intense neoadjuvant hormone therapy in high-risk prostate cancer resulted in favorable pathologic responses (tumor <5 mm) in 21% of patients. Pathologic responses were similar between treatment arms. Part 2 of this study will investigate the impact of adjuvant hormone therapy on biochemical recurrence.

Radiation and Androgen Deprivation Therapy With or Without Docetaxel in the Management of Nonmetastatic Unfavorable-Risk Prostate Cancer: A Prospective Randomized Trial

Although docetaxel is not recommended when managing men with unfavorable-risk prostate cancer (PC) given negative or inconclusive results from previous randomized trials, unstudied benefits may exist.

[Recent advances in high-risk prostate cancer surgery]

The management of high-risk prostate cancer has greatly evolved in recent years. Advances in imaging helps to better define the actual aggressiveness of the disease, to plan the surgical procedure, and to improve the prognostic evaluation of this high-risk of recurrence disease. The information obtained by MRI and by targeted biopsies improves management before surgery. Advances in nuclear medicine and generalization of PSMA-PET scans are beginning to improve the initial stage of diagnosis, thanks to a better detection of lymph node and distant metastases. The oncological interest of these new imaging techniques, which then influence the therapeutic plan, remains to be defined. The curative impact of an extensive lymph node dissection, as currently recommended, remains to be proved, and recently published randomized trials do not provide firm conclusions. The new hormone therapies pave the way for an intensification of perioperative systemic treatment, with a significant action on the tumor tissue, but an impact on survival, which remains to be defined in the context of ongoing randomized trials.

Neoadjuvant Chemohormonal Therapy before Radical Prostatectomy for Japanese Patients with High-Risk Localized Prostate Cancer

BACKGROUND

Radical prostatectomy (RP) is the standard treatment in patients with high-risk prostate cancer (PCa). However, there is a high rate of recurrence, and new approaches are required to improve surgical efficacy. Here, we evaluated the feasibility and safety of neoadjuvant chemohormonal therapy (NCHT) before RP for Japanese patients with high-risk localized prostate cancer (PCa).

METHODS

From February 2009 to April 2016, 21 high-risk patients were enrolled in this prospective study. Patients were treated with docetaxel (70 mg/m²) every four weeks for three cycles and luteinizing hormone-releasing hormone agonist. Patients with grade 3-4 toxicities had 25% dose reductions for the following course.

RESULTS

Median follow-up was 88.6 months. The dose of docetaxel was reduced in 13 patients. The estimated five-year biochemical progression-free survival (bPFS) rate was 57.1%. National Comprehensive Cancer Network criteria (high-risk, but not very high-risk (nVHR) versus VHR) was associated with bPFS (p = 0.03). Five-year bPFS rates in the nVHR and VHR groups were 76.9% and 25.0%, respectively. There was a significant difference in bPFS between the nVHR and VHR groups (p = 0.023) by Kaplan-Meier analysis.

CONCLUSIONS

Although our study included a small number of cases, at least in our exploration, NCHT was safe and feasible. However, more extensive treatment modalities are needed to improve outcomes, especially in VHR patients.

Baseline Testosterone Levels in Men with Clinically Localized High-Risk Prostate Cancer Treated with Radical Prostatectomy with or without Neoadjuvant Chemohormonal Therapy (Alliance)

PURPOSE

Men with low serum testosterone at the time of prostate cancer diagnosis are frequently considered to have more aggressive disease. We examined treatment outcomes in men with clinically localized high-risk cancer to determine if baseline testosterone level identified men at higher risk for cancer progression after treatment.

MATERIALS AND METHODS

Alliance/CALGB 90203 randomized men with clinically localized high-risk prostate cancer to radical prostatectomy alone or neoadjuvant chemohormonal therapy and radical prostatectomy. Men with available baseline testosterone levels who had not received androgen deprivation prior to study enrollment were studied (656). Testosterone level was examined as a continuous variable, as quartiles, and separately in men with an absolute testosterone level above/below 150 ng/dl. Outcomes evaluated were overall survival and event-free survival with events defined by biochemical recurrence, secondary treatment, prostate cancer metastasis, and death.

RESULTS

We were unable to demonstrate a difference between baseline serum testosterone level measured as a continuous variable, as quartiles, or as a dichotomous variable (above/below 150 ng/dl) with the outcomes measured. This finding was observed in both arms of the study.

CONCLUSIONS

Baseline serum testosterone level did not predict outcomes in men with clinically localized high-risk prostate cancer treated with radical prostatectomy alone or neoadjuvant chemohormonal therapy and radical prostatectomy.

Neoadjuvant treatment with androgen receptor signaling inhibitors prior to radical prostatectomy: a systematic review

CONTEXT

There is an urgent need to develop novel treatment strategies in patients with unfavorable intermediate- and high-risk localized prostate cancer (PCa) to optimize the outcome of these patients. Androgen receptor signaling inhibitors (ARSI) have demonstrated a survival benefit in metastatic hormonesensitive and castration-resistant PCa. A similar benefit might be expected in the localized setting.

OBJECTIVE

To perform a systematic review about the role of neoadjuvant ARSI in unfavorable intermediate and high-risk localized PCa.

EVIDENCE ACQUISITION

We performed a systematic review of the following databases: MEDLINE (PubMed), EMBASE, Cochrane Library and Web of Science. Publications of ASCO were consulted to identify meeting abstract with early results of ongoing trials. This systematic review was performed and reported in accordance with the PRISMA guidelines.

EVIDENCE SYNTHESIS

Pathological complete response (pCR) following neoadjuvant ARSI treatment was observed in 4%-13% of the patients. Minimal residual disease response ranged from 36% to 73.9% when defined as residual cancer burden < 0.25 cm³ at final pathology and from 8% to 20% when defined as the diameter of the remaining tumor < 5 mm. Despite intense neoadjuvant ARSI treatment, residual pT3 disease was observed in 48%-76% of the patients. In contrast, positive surgical margins (PSM) were present in only 5%-22%. Only one trial reported BCR following neoadjuvant ARSI therapy (44% BCR at a median follow-up of 4 years).

CONCLUSION

Despite intense neoadjuvant ARSI therapy, pCR is rarely attained and high proportions of pT3 disease are still observed at final pathology. In contrast, promising results are obtained in terms of PSMs. Long-term survival outcomes are eagerly awaited.

Current and emerging therapies for localized high-risk prostate cancer

Introduction: Despite progress in the field of high-risk localized prostate cancer (HRPCa) treatments, high-risk patients treated with curative intent are at increased risk of biochemical recurrence, metastatic progression and cancer-related death. The optimal treatment strategy remains a topic of debate. This review provides an overview of the current and investigational therapeutic options for HRPCa.Areas covered: A PubMed search was performed for papers on the current perspectives on the multimodality treatment of HRPCa. We focus on both primary local treatment as well as systemic treatment options. Finally, relevant ongoing trials focusing on systemic treatments (including [neo]adjuvant treatments) enrolling at least 50 patients were retrieved, to highlight ongoing research and treatment optimization.Expert opinion: Disease progression in HRPCa patients is driven by local tumor extension and subclinical metastases. Therefore, the main treatment concept is a multimodal approach targeting the primary tumor with extended surgery or RT with long-term ADT and simultaneously targeting micro-metastatic deposits. However, there is still room for optimization. Upcoming clinical trials comparing surgery versus RT as local treatment, trials with (neo)adjuvant chemotherapy or androgen receptor signaling inhibitors will likely change the treatment landscape. However, a multimodal treatment strategy will stay as the cornerstone in the treatment of HRPCa.

Aptamer-Functionalized Dendrimer Delivery of Plasmid-Encoding lncRNA MEG3 Enhances Gene Therapy in Castration-Resistant Prostate Cancer

Purpose

The clinical management of patients with castration-resistant prostate cancer (CRPC) is difficult. However, novel treatment methods are gradually being introduced. Considering the adverse effects of traditional treatments, recent studies have investigated gene therapy as a method to combat CRPC; but, the application of long non-coding (lnc) RNA in gene therapy remains scarce, despite their promise. Therefore, it is imperative to develop a system that can efficiently deliver lncRNA for the treatment of CRPC. Here, we investigated the efficacy of a delivery system by introducing the plasmid-encoding tumor suppressor lncRNA MEG3 (pMEG3) in CRPC cells.

Materials and Methods

An EpDT3 aptamer-linked poly(amidoamine) (PAMAM) dendrimer targeting EpCAM was used to deliver pMEG3 in CRPC cells. The PAMAM-PEG-EpDT3/pMEG3 nanoparticles (NPs) were tested using in vitro cellular assays including cellular uptake, entry, and CCK-8 measurement, and tumor growth inhibition, histological assessment, and safety evaluations in in vivo animal models.

Results

The EpDT3 aptamer promoted endocytosis of PAMAM and PAMAM-PEG-EpDT3/pMEG3 NPs in CRPC cells. PAMAM-PEG-EpDT3/pMEG3 NPs exhibited a significant anti-CRPC effect, both in vivo and in vitro, when compared to that of unfunctionalized PAMAM-PEG/pMEG3 NPs.

Conclusion

PAMAM-PEG-EpDT3/pMEG3 NPs can potentially improve gene therapy in CRPC cells.