Post prostatectomy outcomes of patients with high-risk prostate cancer treated with neoadjuvant androgen blockade

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.

Administering [177Lu]Lu-PSMA-617 Prior to Radical Prostatectomy in Men with High-risk Localised Prostate Cancer (LuTectomy): A Single-centre, Single-arm, Phase 1/2 Study

BACKGROUND

High-risk localised prostate cancer (HRCaP) has high rates of biochemical recurrence; [177Lu]Lu-PSMA-617 is effective in men with advanced prostate cancer.

OBJECTIVE

To investigate the dosimetry, safety, and efficacy of upfront [177Lu]Lu-PSMA-617 in men with HRCaP prior to robotic radical prostatectomy (RP).

DESIGN, SETTING, AND PARTICIPANTS

In this single-arm, phase I/II trial, we recruited men with HRCaP (any of prostate-specific antigen [PSA] >20 ng/ml, International Society of Urological Pathology (ISUP) grade group [GG] 3-5, and ≥cT2c), with high tumour uptake on [68Ga]Ga-PSMA-11 positron emission tomography/computed tomography (PSMA PET/CT), and scheduled for RP.

INTERVENTION

Cohort A (n = 10) received one cycle and cohort B (n = 10) received two cycles of [177Lu]Lu-PSMA-617 (5 GBq) followed by surgery 6 weeks later.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was tumour radiation absorbed dose. Adverse events (AEs; Common Terminology Criteria for Adverse Events (CTCAE) version 5.0), surgical safety (Clavien-Dindo), imaging, and biochemical responses were evaluated (ClinicalTrials.gov: NCT04430192).

RESULTS AND LIMITATIONS

Between May 29, 2020 and April 28, 2022, 20 patients were enrolled. The median PSA was 18 ng/ml (interquartile range [IQR] 11-35), Eighteen (90%) had GG ≥3, and six (30%) had N1 disease. The median (IQR) highest tumour radiation absorbed dose after cycle 1 for all lesions was 35.5 Gy (19.5-50.1), with 19.6 Gy (11.3-48.4) delivered to the prostate. Five patients received radiation to lymph nodes. Nine (45%) patients achieved >50% PSA decline. The most common AEs related to [177Lu]Lu-PSMA-617 were grade 1 fatigue in eight (40%), nausea in seven (35%), dry mouth in six (30%), and thrombocytopenia in four (20%) patients. No grade 3/4 toxicities or Clavien 3-5 complications occurred. Limitations include small a sample size.

CONCLUSIONS

In men with HRCaP and high prostate-specific membrane antigen (PSMA) expression, [177Lu]Lu-PSMA-617 delivered high levels of targeted radiation doses with few toxicities and without compromising surgical safety. Further studies of [177Lu]Lu-PSMA-617 in this population are worthwhile to determine whether meaningful long-term oncological benefits can be demonstrated.

PATIENT SUMMARY

In this study, we demonstrate that up to two cycles of [177Lu]Lu-PSMA-617 given prior to radical prostatectomy in patients with high-risk localised prostate cancer are safe and deliver targeted doses of radiation to tumour-affected tissues. It is tolerated well with minimal treatment-related adverse events, and surgery is safe with a low rate of complications. Activity measured through PSA reduction, repeat PSMA PET/CT, and histological response is promising.

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.

The Association Between [68Ga]PSMA PET/CT Response and Biochemical Progression in Patients with High-Risk Prostate Cancer Receiving Neoadjuvant Therapy

Our previous study found that the prostate-specific membrane antigen (PSMA) PET/CT response of primary prostate cancer (PCa) to neoadjuvant therapy can predict the pathologic response. This study was designed to investigate the association between [68Ga]PSMA PET/CT changes and biochemical progression-free survival (bPFS) in high-risk patients who underwent neoadjuvant therapy before radical prostatectomy (RP). Methods: Seventy-five patients with high-risk PCa in 2 phase II clinical trials who received neoadjuvant therapy before RP were included. The patients received androgen deprivation therapy plus docetaxel (n = 33) or androgen deprivation therapy plus abiraterone (n = 42) as neoadjuvant treatment. All patients had serial [68Ga]PSMA PET/CT scans before and after neoadjuvant therapy. Age, initial prostate-specific antigen level, nadir prostate-specific antigen level before RP, tumor grade at biopsy, treatment regimen, clinical T stage, PET imaging features, pathologic N stage, and pathologic response on final pathology were included for univariate and multivariate Cox regression analyses to identify independent predictors of bPFS. Results: With a median follow-up of 30 mo, 18 patients (24%) experienced biochemical progression. Multivariate Cox regression analyses revealed that only SUVmax derived from posttreatment [68Ga]PSMA PET/CT and pathologic response on final pathology were independent factors for the prediction of bPFS, with hazard ratios of 1.02 (95% CI, 1.00-1.04; P = 0.02) and 0.12 (95% CI, 0.02-0.98; P = 0.048), respectively. Kaplan-Meier analysis revealed that patients with a favorable [68Ga]PSMA PET/CT response (posttreatment SUVmax < 8.5) or a favorable pathologic response (pathologic complete response or minimal residual disease) had a significantly lower rate of 3-y biochemical progression. Conclusion: Our results indicated that [68Ga]PSMA PET/CT response was an independent risk factor for the prediction of bPFS in patients with high-risk PCa receiving neoadjuvant therapy and RP, suggesting [68Ga]PSMA PET/CT to be an ideal tool to monitor response to neoadjuvant therapy.

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.

Neoadjuvant radiohormonal therapy for oligo-metastatic prostate cancer: safety and efficacy outcomes from an open-label, dose-escalation, single-center, phase I/II clinical trial

To evaluate the safety and efficacy of neoadjuvant radiohormonal therapy for oligometastatic prostate cancer (OMPC), we conducted a 3 + 3 dose escalation, prospective, phase I/II, single-arm clinical trial (CHiCTR1900025743), in which long-term neoadjuvant androgen deprivation was adopted 1 month before radiotherapy, comprising intensity modulated radiotherapy to the pelvis, and stereotactic body radiation therapy to all extra-pelvic bone metastases for 4-7 weeks, at 39.6, 45, 50.4, and 54 Gy. Robotic-assisted radical prostatectomy was performed after 5-14 weeks. The primary outcome was treatment-related toxicities and adverse events; secondary outcomes were radiological treatment response, positive surgical margin (pSM), postoperative prostate-specific antigen (PSA), pathological down-grading and tumor regression grade, and survival parameters. Twelve patients were recruited from March 2019 to February 2020, aging 66.2 years in average (range, 52-80). Median baseline PSA was 62.0 ng/mL. All underwent RARP successfully without open conversions. Ten patients recorded pathological tumor down-staging (83.3%), and 5 (41.7%) with cN1 recorded negative regional lymph nodes on final pathology. 66.7% (8/12) recorded tumor regression grading (TRG) -I and 25% (3/12) recorded TRG-II. Median follow-up was 16.5 months. Mean radiological progression-free survival (RPFS) was 21.3 months, with 2-year RPFS of 83.3%. In all, neoadjuvant radiohormonal therapy is well tolerated for oligometastatic prostate cancer.

Prostate Cancer in Male-to-Female Transgender Individuals: Histopathologic Findings and Association With Gender-affirming Hormonal Therapy

Male-to-female (MtF) transgender individuals are at risk for prostate cancer, although guidelines for screening and management in this population are not well established. We describe a series of 9 MtF transgender patients who underwent prostate tissue sampling and highlight histopathologic features and challenges related to pathologic interpretation of prostate tissue in this patient population. Seven of 9 total patients were diagnosed with prostate cancer and all had elevated prostate-specific antigen at the time of diagnosis. Three of the 7 patients diagnosed with prostate cancer had received different types of hormone therapy for gender affirmation before the diagnosis of prostate cancer, and in all 3 of these patients, there was histologic evidence of hormone therapy effect in both benign prostate tissue and/or the adenocarcinoma. The 2 patients with benign prostate tissue underwent transurethral resection for lower urinary tract symptoms and were previously on hormone therapy for gender affirmation. Both of these specimens showed diffuse glandular atrophy and basal cell hyperplasia, indicative of hormone therapy effect on benign prostatic tissue. In the patients diagnosed with prostate cancer, a spectrum of grades was observed, ranging from Grade Group 1 to Grade Group 5. Four patients underwent radical prostatectomy, with 2 cases showing extraprostatic extension and Grade Group 5 prostatic adenocarcinoma, and 2 showing Grade Group 2 prostatic adenocarcinoma. Three of the 4 patients who underwent radical prostatectomy had received gender-affirming hormone therapy before surgery, and all 3 of these specimens showed hormone therapy effect in non-neoplastic prostate tissue and focal hormone therapy effect in prostatic adenocarcinoma. The presence of areas of viable carcinoma without hormone therapy effect enabled the assignment of a Gleason score and Grade Group in these 3 cases. Hormone therapy administered for gender identity affirmation induces histopathologic changes to both benign prostate tissue (nonkeratinizing squamous metaplasia, diffuse atrophy, basal cell hyperplasia, and stromal dominance with decreased numbers of glands) and prostatic adenocarcinoma (nuclear pyknosis, atrophy, cytoplasmic vacuolization, and architectural patterns that would qualify for Gleason 4 and 5 in the absence of hormone therapy effect) that have been traditionally seen in cis-male prostate cancer patients receiving hormone therapy. In the absence of hormone therapy, the morphology of prostatic adenocarcinoma in transgender patients shows classic morphologic features similar to those seen in cis-male patients not on hormone therapy. Prostate cancer with hormone therapy effect may not only be histologically quite subtle and may be overlooked if not suspected, but also should not be assigned a Gleason score because the Gleason score would substantially overstate its biologic potential. Therefore, similar to cis-male patients who have received androgen deprivation therapy for prostate cancer, transgender patients on hormone therapy for gender affirmation may be at risk for both underrecognition and over-grading of prostate cancer, particularly if the pathologist is not aware of the clinical history.

ROLE OF ANDROGEN RECEPTOR-TARGETED AGENTS IN LOCALIZED PROSTATE CANCER

Anti-androgen therapy continues to be a basic pilar of treatment for both localized and metastatic prostate cancer. The advent of new generation of androgen receptor targeted agents (ARTA) transformed the care of patients with advanced disease. After such a success, the steps were taken to incorporate a new generation of ARTAs into the treatment landscape of localized prostate cancer. High-risk prostate cancer represents the most aggressive form of localized disease with significant metastatic potential and poor outcome. Here, the impact of novel therapies will likely be profound and transforming. This clinical space has already been a showcase for multidisciplinary treatment where the combination of local therapies with systemic treatment gradually improved patient outcomes and the chances of cure. The most recent step in redefining the treatment of localized disease is the adoption of novel ARTAs moving forward the multidisciplinary platform. In this narrative review, we discuss current clinical evidence supporting the use of novel ARTAs in patients with localized high-risk prostate cancer and cover recent developments in biomarker-driven strategies for treatment individualization in this clinical context.

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.

Comparison of short-term and long-term neoadjuvant hormone therapy prior to radical prostatectomy: a systematic review and meta-analysis

PURPOSE

This study aimed to evaluate the efficacy of long-term neoadjuvant androgen-deprivation therapy (ADT) before radical prostatectomy (RP).

METHODS

We conducted meta-analyses and network meta-analyses, which included randomized controlled trials that assessed patients with prostate cancer (PC) who received either short-term (<6 months) or long-term (≥6 months) neoadjuvant ADT before RP.

RESULTS

Thirteen articles with 2778 patients were eligible for analysis. Short-term neoadjuvant ADT was neither associated with biochemical recurrence (OR 1.19, 95% CI, 0.93-1.51, p = 0.17), metastasis (OR 0.73, 95% CI, 0.45-1.19, p = 0.21), nor overall mortality (OR 0.72, 95% CI 0.43-1.21, p = 0.22); no study investigated survival outcomes in patients on long-term neoadjuvant ADT. In terms of pathologic outcomes, long-term neoadjuvant ADT was significantly associated with a reduced risk of positive surgical margin (SM) and an increased rate of organ-confined disease (OCD) compared to short-term neoadjuvant ADT (OR 0.56, 95% CI 0.39-0.80, p = 0.001, and OR 1.48, 95% CI 1.10-1.99, p = 0.009, respectively). These findings were confirmed in the network meta-analyses. Meanwhile, only a non-significant trend favoring long-term neoadjuvant ADT was observed for pathologic complete response (OR 1.98, 95% Crl 1.00-3.93).

CONCLUSION

Long-term neoadjuvant ADT was associated with more favorable pathologic outcomes, but whether these findings translate into favorable survival outcomes still remains unproven due to very limited evidence. Since there are no reliable survival data, long-term neoadjuvant ADT before RP should not be used in clinical practice until more robust evidence arises from ongoing trials.

Randomized Phase 2 Trial of Abiraterone Acetate Plus Prednisone, Degarelix, or the Combination in Men with Biochemically Recurrent Prostate Cancer After Radical Prostatectomy

Background

Phase 2 trial endpoints that can be utilized in high-risk biochemical recurrence (BCR) after prostatectomy as a way of more rapidly identifying treatments for phase 3 trials are urgently needed. The efficacy of abiraterone acetate plus prednisone (AAP) in BCR is unknown.

Objective

To compare the rates of complete biochemical responses after testosterone recovery after 8 mo of AAP and degarelix, a gonadotropin-releasing hormone antagonist, alone or in combination.

Design, setting, and participants

Patients with BCR (prostate-specific antigen [PSA] ≥1.0 ng/ml, PSA doubling time ≤9 mo, no metastases on standard imaging, and testosterone ≥150 ng/dl) after prostatectomy (with or without prior radiotherapy) were included in this study.

Intervention

Patients were randomized to AAP (arm 1), AAP with degarelix (arm 2), or degarelix (arm 3) for 8 mo, and monitored for 18 mo.

Outcome measurements and statistical analysis

The primary endpoint was undetectable PSA with testosterone >150 ng/dl at 18 mo. Secondary endpoints were undetectable PSA at 8 mo and time to testosterone recovery.

Results and limitations

For the 122 patients enrolled, no difference was found between treatments for the primary endpoint (arm 1: 5.1% [95% confidence interval {CI}: 1–17%], arm 2: 17.1% [95% CI: 7–32%], arm 3: 11.9% [95% CI: 4–26%]; arm 1 vs 2, p = 0.93; arm 2 vs 3, p = 0.36). AAP therapy showed the shortest median time to testosterone recovery (36.0 wk [95% CI: 35.9–36.1]) relative to degarelix (52.9 wk [95% CI: 49.0–56.0], p < 0.001). Rates of undetectable PSA at 8 mo differed between AAP with degarelix and degarelix alone (p = 0.04), but not between AAP alone and degarelix alone (p = 0.12). Limitations of this study include a lack of long-term follow-up.

Conclusions

Rates of undetectable PSA levels with testosterone recovery were similar between arms, suggesting that increased androgen suppression with AAP and androgen deprivation therapy (ADT) is unlikely to eradicate recurrent disease compared with ADT alone.

Patient summary

We evaluated the use of abiraterone acetate plus prednisone (AAP) and androgen deprivation therapy (ADT), AAP alone, or ADT alone in men with biochemically recurrent, nonmetastatic prostate cancer. While more men who received the combination had an undetectable prostate-specific antigen (PSA) level at 8 mo on treatment, once men came off treatment and testosterone level rose, there was no difference in the rates of undetectable PSA levels. This suggests that the combination is not able to eradicate disease any better than ADT alone.

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.

Molecular features of exceptional response to neoadjuvant anti-androgen therapy in high-risk localized prostate cancer

High-risk localized prostate cancer (HRLPC) is associated with a substantial risk of recurrence and disease mortality. Recent clinical trials have shown that intensifying anti-androgen therapies administered before prostatectomy can induce pathologic complete responses or minimal residual disease, called exceptional response, although the molecular determinants of these clinical outcomes are largely unknown. Here, we perform whole-exome and transcriptome sequencing on pre-treatment multi-regional tumor biopsies from exceptional responders (ERs) and non-responders (NRs, pathologic T3 or lymph node-positive disease) to intensive neoadjuvant anti-androgen therapies. Clonal SPOP mutation and SPOPL copy-number loss are exclusively observed in ERs, while clonal TP53 mutation and PTEN copy-number loss are exclusively observed in NRs. Transcriptional programs involving androgen signaling and TGF-β signaling are enriched in ERs and NRs, respectively. These findings may guide prospective validation studies of these molecular features in large HRLPC clinical cohorts treated with neoadjuvant anti-androgens to improve patient stratification.

PSMA PET predicts metastasis-free survival in the setting of salvage radiotherapy after radical prostatectomy

INTRODUCTION

To evaluate the impact of PSMA PET (prostate specific membrane antigen positron emission tomography) findings prior to salvage radiotherapy (SRT) in recurrent prostate cancer (PCa) after radical prostatectomy (RP) on metastasis-free survival (MFS).

PATIENTS AND METHODS

Between 01/2012 and 12/2018, 1,599 patients received SRT for biochemical recurrence after RP at our institution. Five-year MFS of "positive PSMA PET" (n = 49) vs. "negative PSMA PET" (n = 106) vs. "no PSMA PET" (n = 1,599) prior to SRT was determined. For all time to event analyses, uni- and multivariable Cox's proportional hazards models and univariable Kaplan-Meier analyses were applied, with a significance threshold of P < 0.05. Further 4:1 propensity score matching for patient, cancer and treatment characteristics was performed to account for residual differences between groups.

RESULTS

Of PSMA PET patients, 106 patients exhibited "negative PSMA PET" (68.4%) and 49 exhibited "positive PSMA PET" (31.6%). Median PSA at recurrence did not differ between groups (0.2 ng/ml; P= 0.4). After 4:1 propensity score matching, 5-year MFS between "no PSMA PET" and "negative PSMA PET" was 94.4 vs. 93.0%, respectively (P = 0.8). For "no PSMA PET" versus "positive PSMA PET", 5-year MFS was significantly lower in "positive PSMA PET" (92.3 vs. 48.5%, respectively P < 0.0001). Finally, "positive PSMA PET" was independently associated with worse MFS compared to "no PSMA PET" after multivariable adjustment in the overall cohort (HR 13.8, CI 7.5-25.2, P < 0.001).

CONCLUSIONS

Locoregional positive PSMA PET findings in recurrent patients after RP are highly predictive of worse MFS in the setting of SRT.

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.

Neoadjuvant Androgen Deprivation Therapy Effects on Perioperative Outcomes Prior to Radical Prostatectomy: Eleven Years of Experiences at Ramathibodi Hospital

Objective

The aim of this study was to demonstrate the efficacy of neoadjuvant androgen deprivation therapy (NADT) on perioperative outcomes in patients who underwent radical prostatectomy (RP).

Materials and Methods

From January 2008 to July 2018, we collected retrospective data of patients with clinically localized prostate cancer who underwent RP to assess their perioperative and pathological outcomes. The data included age, body mass index (BMI), serum prostate specific antigen (PSA) level, clinical stage, neoadjuvant ADT usage, operative time, estimated blood loss (EBL), perioperative complications, blood transfusion rate, adjacent organ injury rate, length of hospital stay, pathological stage, Gleason score (GS) of the biopsy and pathological specimen, specimen weight (g), and margin status.

Results

Of the 718 RPs performed, 138 (19.22%) were NADT and 580 (80.78%) were non-NADT. Patients who underwent NADT had a significant benefit in operative time (185 vs 195 mins), EBL (300 vs 500 mL) and specimen weight. These benefits were more obvious in non-low risk prostate cancer with less operative time, EBL, blood transfusion rate, length of hospital stay and specimen weight. However, the margin status and adjacent organ injury rate were similar in the NADT and non-NADT groups.

Conclusion

NADT provides significantly better perioperative outcomes, especially in non-low risk prostate cancer, and has comparable pathological outcomes.

Targeting backdoor androgen synthesis through AKR1C3 inhibition: A presurgical hormonal ablative neoadjuvant trial in high-risk localized prostate cancer

BACKGROUND

Localized prostate cancers (PCs) may resist neoadjuvant androgen receptor (AR)-targeted therapies as a result of persistent intraprostatic androgens arising through upregulation of steroidogenic enzymes. Therefore, we sought to evaluate clinical effects of neoadjuvant indomethacin (Indo), which inhibits the steroidogenic enzyme AKR1C3, in addition to combinatorial anti-androgen blockade, in men with high-risk PC undergoing radical prostatectomy (RP).

METHODS

This was an open label, single-site, Phase II neoadjuvant trial in men with high to very-high-risk PC, as defined by NCCN criteria. Patients received 12 weeks of apalutamide (Apa), abiraterone acetate plus prednisone (AAP), degarelix, and Indo followed by RP. Primary objective was to determine the pathologic complete response (pCR) rate. Secondary objectives included minimal residual disease (MRD) rate, defined as residual cancer burden (RCB) ≤ 0.25cm³ (tumor volume multiplied by tumor cellularity) and elucidation of molecular features of resistance.

RESULTS

Twenty patients were evaluable for the primary endpoint. Baseline median prostate-specific antigen (PSA) was 10.1 ng/ml, 4 (20%) patients had Gleason grade group (GG) 4 disease and 16 had GG 5 disease. At RP, 1 (5%) patient had pCR and 6 (30%) had MRD. Therapy was well tolerated. Over a median follow-up of 23.8 months, 1 of 7 (14%) men with pathologic response and 6 of 13 (46%) men without pathologic response had a PSA relapse. There was no association between prostate hormone levels or HSD3B1 genotype with pathologic response.

CONCLUSIONS

In men with high-risk PC, pCR rates remained low even with combinatorial AR-directed therapy, although rates of MRD were higher. Ongoing follow-up is needed to validate clinical outcomes of men who achieve MRD.

Neoadjuvant Approaches Prior To Radical Prostatectomy

Patients with high-risk localized prostate cancer benefit from multimodality therapy of curative intent. Androgen-deprivation therapy (ADT) combined with radiation improves survival in this population. However, prior clinical trials of neoadjuvant ADT and surgery failed to consistently demonstrate a survival advantage. The development of novel, more potent hormonal agents presents an opportunity to revisit the potential for neoadjuvant therapy to improve long-term outcomes for patients with localized prostate cancer. We review recent advances in neoadjuvant approaches for prostate cancer and emerging clinical trials data supporting the use of neoadjuvant therapy prior to radical prostatectomy.

Impact of Pathogenic Germline DNA Damage Repair alterations on Response to Intense Neoadjuvant Androgen Deprivation Therapy in High-risk Localized Prostate Cancer

BACKGROUND

Intense neoadjuvant androgen deprivation therapy (ADT) before radical prostatectomy (RP) is an investigational approach to reduce recurrence rates in men with high-risk localized prostate cancer (PCa). The impact of germline DNA damage repair (gDDR) gene alterations on response to intense neoadjuvant ADT is not known.

OBJECTIVE

To evaluate the prevalence of gDDR alterations among men with localized PCa at high risk of recurrence and evaluate their impact on response to intense neoadjuvant ADT.

DESIGN, SETTING, AND PARTICIPANTS

We performed germline panel sequencing for 201 men with intermediate- and high-risk localized PCa from five randomized multicenter clinical trials of intense neoadjuvant ADT before RP.

INTERVENTION

Intense neoadjuvant ADT followed by RP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The prevalence of pathogenic gDDR alterations and their association with exceptional pathologic response (complete response or minimal residual disease, defined as residual tumor with the largest cross-section dimension ≤5 mm) to intense neoadjuvant ADT and rates of post-RP biochemical recurrence.

RESULTS AND LIMITATIONS

Pathogenic gDDR alterations were detected in 19 (9.5%) of the 201 PCa patients. The most frequently altered genes were BRCA2 (n = 6; 3.0%) and ATM (n = 4; 2.0%). Patients with gDDR alterations exhibited similar rates of exceptional pathologic response (26% vs 22%), pT3 disease (42% vs 53%), lymph node involvement (5.3% vs 10%), extraprostatic extension (35% vs 54%), and positive margins (5.3% vs 13%) to patients without gDDR alterations (all p > 0.05). The 3-yr biochemical recurrence-free survival was also similar at 45% (95% confidence interval 7.9-78%) for men with gDDR alterations and 55% (95% confidence interval 44-64%) for men without gDDR alterations.

CONCLUSIONS

gDDR alterations are common among men with intermediate- and high-risk localized PCa. Men with gDDR alterations appear to have a comparable response to intense neoadjuvant ADT to that among men without gDDR alterations and should not be excluded from consideration for this treatment approach.

PATIENT SUMMARY

Intense therapy to inhibit the production of androgen hormones (eg, testosterone) before surgery may minimize the risk of cancer recurrence for men with high-risk localized prostate cancer. Inherited mutations in certain DNA repair genes are associated with particularly high rates of recurrence. We found that men with these mutations respond equally well to this intense androgen inhibition before surgery as men without the mutations.

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.

The Impact of Neoadjuvant Hormone Therapy on Surgical and Oncological Outcomes for Patients With Prostate Cancer Before Radical Prostatectomy: A Systematic Review and Meta-Analysis

Objective

This systematic study aimed to assess and compare the comprehensive evidence regarding the impact of neoadjuvant hormone therapy (NHT) on surgical and oncological outcomes of patients with prostate cancer (PCa) before radical prostatectomy (RP).

Methods

Literature searches were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Using PubMed, Web of Science, Chinese National Knowledge Infrastructure, and Wanfang databases, we identified relevant studies published before July 2020. The pooled effect sizes were calculated in terms of the odds ratios (ORs)/standard mean differences (SMDs) with 95% confidence intervals (CIs) using the fixed or random-effects model.

Results

We identified 22 clinical trials (6 randomized and 16 cohort) including 20,199 patients with PCa. Our meta-analysis showed no significant differences in body mass index (SMD = 0.10, 95% CI: -0.08-0.29, p = 0.274) and biopsy Gleason score (GS) (OR = 1.33, 95% CI: 0.76-2.35 p = 0.321) between the two groups. However, the NHT group had a higher mean age (SMD = 0.19, 95% CI: 0.07-0.31, p = 0.001), preoperative prostate-specific antigen (OR = 0.47, 95% CI: 0.19-0.75, p = 0.001), and clinic tumor stage (OR = 2.24, 95% CI: 1.53-3.29, p < 0.001). Compared to the RP group, the NHT group had lower positive surgical margins (PSMs) rate (OR = 0.44, 95% CI: 0.29-0.67, p < 0.001) and biochemical recurrence (BCR) rate (OR = 0.47, 95% CI: 0.26-0.83, p = 0.009). Between both groups, there were no significant differences in estimated blood loss (SMD = -0.06, 95% CI: -0.24-0.13, p = 0.556), operation time (SMD = 0.20, 95% CI: -0.12-0.51, p = 0.219), pathological tumor stage (OR = 0.76, 95% CI: 0.54-1.06, p = 0.104), specimen GS (OR = 0.91, 95% CI: 0.49-1.68, p = 0.756), and lymph node involvement (OR = 0.76, 95% CI: 0.40-1.45, p = 0.404).

Conclusions

NHT prior to RP appeared to reduce the tumor stage, PSMs rate, and risk of BCR in patients with PCa. According to our data, NHT may be more suitable for older patients with higher tumor stage. Besides, NHT may not increase the surgical difficulty of RP.

Sequential Prostate Magnetic Resonance Imaging in Newly Diagnosed High-risk Prostate Cancer Treated with Neoadjuvant Enzalutamide is Predictive of Therapeutic Response

PURPOSE

For high-risk prostate cancer, standard treatment options include radical prostatectomy (RP) or radiotherapy plus androgen deprivation therapy (ADT). Despite definitive therapy, many patients will have disease recurrence. Imaging has the potential to better define characteristics of response and resistance. In this study, we evaluated prostate multiparametric MRI (mpMRI) before and after neoadjuvant enzalutamide plus ADT.

PATIENTS AND METHODS

Men with localized intermediate- or high-risk prostate cancer underwent a baseline mpMRI and mpMRI-targeted biopsy followed by a second mpMRI after 6 months of enzalutamide and ADT prior to RP. Specimens were sectioned in the same plane as mpMRI using patient-specific 3D-printed molds to permit mpMRI-targeted biopsies to be compared with the same lesion from the RP. Specimens were analyzed for imaging and histologic correlates of response.

RESULTS

Of 39 patients enrolled, 36 completed imaging and RP. Most patients (92%) had high-risk disease. Fifty-eight lesions were detected on baseline mpMRI, of which 40 (69%) remained measurable at 6-month follow-up imaging. Fifty-five of 59 lesions (93%) demonstrated >50% volume reduction on posttreatment mpMRI. Three of 59 lesions (5%) demonstrated growth in size at follow-up imaging, with two lesions increasing more than 3-fold in volume. On whole-mount pathology, 15 patients demonstrated minimal residual disease (MRD) of <0.05 cc or pathologic complete response. Low initial mpMRI relative tumor burden was most predictive of MRD on final pathology.

CONCLUSIONS

Low relative lesion volume at baseline mpMRI was predictive of pathologic response. A subset of patients had limited response. Selection of patients based on these metrics may improve outcomes in high-risk disease.

Surgical management of high-risk, localized prostate cancer

High-risk prostate cancer is a heterogeneous disease that lacks clear consensus on its ideal management. Historically, non-surgical treatment was the preferred strategy, and several studies demonstrated improved survival among men with high-risk disease managed with the combination of radiotherapy and androgen deprivation therapy (ADT) compared with ADT alone. However, practice trends in the past 10-15 years have shown increased use of radical prostatectomy with pelvic lymph node dissection for primary management of high-risk, localized disease. Radical prostatectomy, as a primary monotherapy, offers the potential benefits of avoiding ADT, reducing rates of symptomatic local recurrence, enabling full pathological tumour staging and potentially reducing late adverse effects such as secondary malignancy compared with radiation therapy. Retrospective studies have reported wide variability in short-term (pathological) and long-term (oncological) outcomes of radical prostatectomy. Surgical monotherapy continues to be appropriate for selected patients, whereas in others the best treatment strategy probably involves a multimodal approach. Appropriate risk stratification utilizing clinical, pathological and potentially also genomic risk data is imperative in the initial management of men with prostate cancer. However, data from ongoing and planned prospective trials are needed to identify the optimal management strategy for men with high-risk, localized prostate cancer.

Battling the two-headed dragon of prostate cancer targeted therapy

Neoadjuvant intense androgen deprivation therapy for high-risk localized prostate cancer is an emerging but unproven treatment paradigm that is hoped to delay or prevent disease recurrence. We found that a patient enrolled in a clinical trial harbored two completely independent prostate cancers that responded differently to this therapy.

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

PURPOSE

Radical prostatectomy (RP) alone is often inadequate in curing men with clinically localized, high-risk prostate cancer (PC). We hypothesized that chemohormonal therapy (CHT) with androgen-deprivation therapy plus docetaxel before RP would improve biochemical progression-free survival (BPFS) over RP alone.

PATIENTS AND METHODS

Men with clinically localized, high-risk PC were assigned to RP alone or neoadjuvant CHT with androgen deprivation plus docetaxel (75 mg/m² body surface area every 3 weeks for 6 cycles) and RP. The primary end point was 3-year BPFS. Biochemical failure was defined as a serum prostate-specific antigen level > 0.2 ng/mL that increased on 2 consecutive occasions that were at least 3 months apart. Secondary end points included 5-year BPFS, overall BPFS, local recurrence, metastasis-free survival (MFS), PC-specific mortality, and overall survival (OS).

RESULTS

In total, 788 men were randomly assigned. Median follow-up time was 6.1 years. The overall rates of grade 3 and 4 adverse events during chemotherapy were 26% and 19%, respectively. No difference was seen in 3-year BPFS between neoadjuvant CHT plus RP and RP alone (0.89 v 0.84, respectively; 95% CI for the difference, -0.01 to 0.11; P = .11). Neoadjuvant CHT was associated with improved overall BPFS (hazard ratio [HR], 0.69; 95% CI, 0.48 to 0.99), improved MFS (HR, 0.70; 95% CI, 0.51 to 0.95), and improved OS (HR, 0.61; 95% CI, 0.40 to 0.94) compared with RP alone.

CONCLUSION

The primary study end point, 3-year BPFS, was not met. Although some improvement was seen in secondary end points, any potential benefit must be weighed against toxicity. Our data do not support the routine use of neoadjuvant CHT and RP in patients with clinically localized, high-risk PC at this time.

Recent Advances in the Management of High-Risk Localized Prostate Cancer: Local Therapy, Systemic Therapy, and Biomarkers to Guide Treatment Decisions

High-risk prostate cancer accounts for approximately 15% of all prostate cancer diagnoses. Patients with high-risk disease have an increased risk of developing biochemical recurrence, metastases, and death from prostate cancer. As the optimal management of high-risk disease in patients with prostate cancer continues to evolve, the contemporary treatment paradigm is moving toward a multidisciplinary integrated approach of systemic and local therapy for patients with high-risk disease. The strategies for definitive, adjuvant, and salvage local treatment, including radical prostatectomy or radiation therapy, serve as the backbone of therapy for patients with localized disease. Systemic therapy decisions regarding use in combination with surgery, choice of therapy (hormone therapy, chemotherapy), and treatment duration continue to be refined. As more effective hormonal agents populate the treatment landscape for advanced prostate cancer, including abiraterone and next-generation antiandrogens, an opportunity is provided to explore these treatments in patients with localized disease in the hope of improving the long-term outcome for patients. Integration of innovative blood and tissue-based biomarkers to guide therapy selection for patients with high-risk disease is an area of active research. Contemporary studies are using such biomarkers to stratify patients and select therapies. In this review, we summarize contemporary evidence for local treatment strategies, systemic therapy options, and biomarkers in development for the management of high-risk prostate cancer in patients.

Optimizing the role of androgen deprivation therapy in advanced prostate cancer: Challenges beyond the guidelines

BACKGROUND

For specific clinical indications, androgen deprivation therapy (ADT) will induce disease prostate cancer (PC) regression, relieve symptoms and prolong survival; however, ADT has a well-described range of side effects, which may have a detrimental effect on the patient's quality of life, necessitating additional interventions or changes in PC treatment. The risk-benefit analysis for initiating ADT in PC patients throughout the PC disease continuum warrants review.

METHODS

A 14-member panel comprised of urologic and medical oncologists were chosen for an expert review panel, to provide guidance on a more judicious use of ADT in advanced PC patients. Panel members were chosen based upon their academic and community experience and expertise in the management of PC patients. Four academic members of the panel served as group leaders; the remaining eight panel members were from Large Urology Group Practice Association practices with proven experience in leading their advanced PC clinics. The panel members were assigned to four separate working groups, and were tasked with addressing the role of ADT in specific PC settings.

RESULTS

This article describes the practical recommendations of an expert panel for the use of ADT throughout the PC disease continuum, as well as an algorithm summarizing the key recommendations. The target for this publication is all providers (urologists, medical oncologists, radiation oncologists, or advanced practice providers) who evaluate and manage advanced PC patients, regardless of their practice setting.

CONCLUSION

The panel has provided recommendations for monitoring PC patients while on ADT, recognizing that PC patients will progress despite testosterone suppression and, therefore, early identification of conversion from castrate-sensitive to castration resistance is critical. Also, the requirement to both identify and mitigate side effects of ADT as well as the importance of quality of life maintenance are essential to the optimization of patient care, especially as more combinatorial therapeutic strategies with ADT continue to emerge.

Neoadjuvant Leuprolide Therapy with Radical Prostatectomy: Long-term Effects on Health-related Quality of Life

BACKGROUND

Neoadjuvant androgen ablation (neoadjuvant androgen deprivation therapy [NADT]) is used prior to radical prostatectomy, contrary to guidelines, but its long-term effects on quality of life is unknown.

OBJECTIVE

To determine the effect of NADT on patient's long-term recovery following surgery.

DESIGN, SETTING, AND PARTICIPANTS

From March 2011 to August 2013, 5808 men with newly diagnosed prostate were followed up to 24 mo. A cohort of men who received NADT prior to robotic-assisted laparoscopic prostatectomy (RALP; n=51) was compared 1:3 with a matched group that underwent RALP only (n=153).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Patients were matched on Charlson comorbidities, biopsy Gleason score, and node status on final pathology. The Kruskall-Wallis test was used to compare the groups on their bowel, urinary, sexual, and hormonal domains of the 26-item Expanded Prostate Cancer Index Composite at baseline and at 1, 3, 6, 12, 18, and 24 mo postoperatively.

RESULTS AND LIMITATIONS

The urinary irritative, urinary incontinence, and bowel domains were similar in the two groups during the 24 mo (p=0.832, 0.901, and 0.732, respectively). In the hormonal domain, the NADT group did worse (p<0.001). The sexual domain was also worse for the NADT group. However, when accounting for nerve sparing, there was no significant difference in sexual outcomes between the two groups (p=0.069).

CONCLUSIONS

Patients who received NADT prior to RALP do not have worse sexual function, but have worse hormonal scores for up to 2yr after surgery.

PATIENT SUMMARY

Neoadjuvant androgen deprivation therapy (NADT) is administered prior to robotic-assisted laparoscopic prostatectomy (RALP), contrary to clinical guidelines. NADT may not have worse sexual function outcomes up to 2yr after RALP.

A case report of multiple primary prostate tumors with differential drug sensitivity

Localized prostate cancers are genetically variable and frequently multifocal, comprising spatially distinct regions with multiple independently-evolving clones. To date there is no understanding of whether this variability can influence management decisions for patients with prostate tumors. Here, we present a single case from a clinical trial of neoadjuvant intense androgen deprivation therapy. A patient was diagnosed with a large semi-contiguous tumor by imaging, histologically composed of a large Gleason score 9 tumor with an adjacent Gleason score 7 nodule. DNA sequencing demonstrates these are two independent tumors, as only the Gleason 9 tumor harbors single-copy losses of PTEN and TP53. The PTEN/TP53-deficient tumor demonstrates treatment resistance, selecting for subclones with mutations to the remaining copies of PTEN and TP53, while the Gleason 7 PTEN-intact tumor is almost entirely ablated. These findings indicate that spatiogenetic variability is a major confounder for personalized treatment of patients with prostate cancer.

Association of mTOR Pathway Markers and Clinical Outcomes in Patients with Intermediate-/High-risk Prostate Cancer: Long-Term Analysis

INTRODUCTION

The mammalian target of rapamycin (mTOR) pathway is up-regulated in prostate cancer (PCa). We evaluated the tumor tissue expression of downstream mTOR targets in patients with intermediate- and high-risk (IR/HR) PCa and their ability to predict outcome after radical prostatectomy (RP).

PATIENTS AND METHODS

Immunohistochemical (IHC) analysis using antibodies against PTEN, mTOR, p-mTOR, pAKT, pS6, and Ki-67 was performed on a tissue microarray constructed from formalin-fixed paraffin-embedded RP specimens. The marker expression was analyzed to determine their predictability for biochemical recurrence (BCR).

RESULTS

Tumor tissue from 217 patients (86 IR/131 HR) was analyzed. The most frequent markers were p-mTOR, which was expressed in most cases (85%), whereas PTEN and pS6 were detected in 53% and 40% of the cases, respectively. Overexpression of PTEN (P = .02) and pS6 (P < .001) was associated with HR features. With a median follow up of 13.5 years, 39% (77/196) of patients developed BCR after RP, more frequently (31%) in patients with HR disease (P < .001). Overexpression of pS6 (P = .036), Ki67% (P = .024), and lack of expression of mTOR (P = .021) were associated with BCR. The 5- and 10-year survival rate was 81% and 66%, respectively.

CONCLUSIONS

Protein expression of downstream mTOR molecules was significantly associated with outcome of patients with IR and HR PCa. Markers of the mTOR pathway could be incorporated in clinical studies evaluating inhibitors of the signaling pathway for treatment selection in men with PCa.

Offsetting Expression Profiles of Prognostic Markers in Prostate Tumor vs. Its Microenvironment

Diagnosis of the presence of tumors and subsequent prognosis based on tumor microenvironment becomes more clinically practical because tumor-adjacent tissues are easy to collect and they are more genetically homogeneous. The purpose of this study was to identify new prognostic markers in prostate stroma that are near the tumor. We have demonstrated the prognostic features of FGFR1, FRS2, S6K1, LDHB, MYPT1, and P-LDHA in prostate tumors using tissue microarrays (TMAs) which consist of 241 patient samples from Massachusetts General Hospital (MGH). In this study, we investigated these six markers in the tumor microenvironment using an Aperio Imagescope system in the same TMAs. The joint prognostic power of markers was further evaluated and classified using a new algorithm named Weighted Dichotomizing. The classifier was verified via rigorous 10-fold cross validation. Statistical analysis of the protein expression indicated that in tumor-adjacent stroma FGFR1 and MYPT1 were significantly correlated with patient outcomes and LDHB showed the outcome-association tendency. More interestingly, these correlations were completely opposite regarding tumor tissue as previously reported. The results suggest that prognostic testing should utilize either tumor-enriched tissue or stroma with distinct signature profiles rather than using mixture of both tissue types. The new classifier based on stroma tissue has potential value in the clinical management of prostate cancer patients.

mpMRI preoperative staging in men treated with antiandrogen and androgen deprivation therapy before robotic prostatectomy

INTRODUCTION

Using multiparametric magnetic resonance imaging (mpMRI), we sought to preoperatively characterize prostate cancer (PCa) in the setting of antiandrogen plus androgen deprivation therapy (AA-ADT) prior to robotic-assisted radical prostatectomy (RARP). We present our preliminary findings regarding mpMRI depiction of changes of disease staging features and lesion appearance in treated prostate.

METHODS

Prior to RARP, men received 6 months of enzalutamide and goserelin. mpMRI consisting of T2 weighted, b = 2,000 diffusion weighted imaging, apparent diffusion coefficient mapping, and dynamic contrast enhancement sequences was acquired before and after neoadjuvant therapy. Custom MRI-based prostate molds were printed to directly compare mpMRI findings to H&E whole-mount pathology as part of a phase II clinical trial (NCT02430480).

RESULTS

Twenty men underwent imaging and RARP after a regimen of AA-ADT. Positive predictive values for post-AA-ADT mpMRI diagnosis of extraprostatic extension, seminal vesicle invasion, organ-confined disease, and biopsy-confirmed PCa lesions were 71%, 80%, 80%, and 85%, respectively. Post-treatment mpMRI correctly staged disease in 15/20 (75%) cases with 17/20 (85%) correctly identified as organ-confined or not. Of those incorrectly staged, 2 were falsely positive for higher stage features and 1 was falsely negative. Post-AA-ADT T2 weighted sequences best depicted presence of PCa lesions as compared to diffusion weighted imaging and dynamic contrast enhancement sequences.

CONCLUSION

mpMRI proved reliable in detecting lesion changes after antiandrogen therapy corresponding to PCa pathology. Therefore, mpMRI of treated prostates may be helpful for assessing men for surgical planning and staging.

Targeting the androgen receptor and overcoming resistance in prostate cancer

PURPOSE OF REVIEW

Prostate cancer (PCa) is diagnosed in one out of every nine men and is the second leading cause of cancer death among men. Although therapies targeting the androgen receptor (AR) are highly effective, development of resistance is universal and remains a major therapeutic challenge. Nonetheless, signaling via AR is frequently maintained despite standard androgen-signaling inhibition. We review the current understanding of mechanisms of resistance as well as therapeutic approaches to improving treatment of PCa via targeting of the AR.

RECENT FINDINGS

Resistance to AR-targeting therapies may be mediated by several mechanisms, including amplification, mutation, and alternative splicing of AR; intratumoral androgen synthesis; activation of alternative signaling pathways; and in a minority of cases, emergence of AR-independent phenotypes. Recent trials demonstrate that intensification of androgen blockade in metastatic castration-sensitive PCa can significantly improve survival. Similar strategies are being explored in earlier disease states. In addition, several other cellular signaling pathways have been identified as mechanisms of resistance, offering opportunities for cotargeted therapy. Finally, immune-based approaches are in development to complement AR-targeted therapies.

SUMMARY

Targeting the AR remains a critical focus in the treatment of PCa.

Evaluation of Intense Androgen Deprivation Before Prostatectomy: A Randomized Phase II Trial of Enzalutamide and Leuprolide With or Without Abiraterone

PURPOSE

Patients with locally advanced prostate cancer have an increased risk of cancer recurrence and mortality. In this phase II trial, we evaluate neoadjuvant enzalutamide and leuprolide (EL) with or without abiraterone and prednisone (ELAP) before radical prostatectomy (RP) in men with locally advanced prostate cancer.

PATIENTS AND METHODS

Eligible patients had a biopsy Gleason score of 4 + 3 = 7 or greater, prostate-specific antigen (PSA) greater than 20 ng/mL, or T3 disease (by prostate magnetic resonance imaging). Lymph nodes were required to be smaller than 20 mm. Patients were randomly assigned 2:1 to ELAP or EL for 24 weeks followed by RP. All specimens underwent central pathology review. The primary end point was pathologic complete response or minimal residual disease (residual tumor ≤ 5 mm). Secondary end points were PSA, surgical staging, positive margins, and safety. Biomarkers associated with pathologic outcomes were explored.

RESULTS

Seventy-five patients were enrolled at four centers. Most patients had high-risk disease by National Comprehensive Cancer Network criteria (n = 65; 87%). The pathologic complete response or minimal residual disease rate was 30% (n = 15 of 50) in ELAP-treated patients and 16% (n = four of 25) in EL-treated patients (two-sided P = .263). Rates of ypT3 disease, positive margins, and positive lymph nodes were similar between arms. Treatment was well-tolerated. Residual tumors in the two arms showed comparable levels of ERG, PTEN, androgen receptor PSA, and glucocorticoid receptor expression. Tumor ERG positivity and PTEN loss were associated with more extensive residual tumors at RP.

CONCLUSION

Neoadjuvant hormone therapy followed by RP in locally advanced prostate cancer resulted in favorable pathologic responses in some patients, with a trend toward improved pathologic outcomes with ELAP. Longer follow-up is necessary to evaluate the impact of therapy on recurrence rates. The potential association of ERG and PTEN alterations with worse outcomes warrants additional investigation.

Apalutamide for the treatment of prostate cancer

INTRODUCTION

Five new agents have been shown to prolong survival in patients with metastatic castration-resistant prostate cancer, including two targeting androgen receptor signaling (abiraterone acetate plus prednisone; enzalutamide). Recognition that these tumors remain driven by androgen receptor signaling has prompted clinical evaluation of these agents at earlier states in the prostate cancer disease continuum, along with the continued development of new agents targeting this pathway. Areas covered: This article focuses on apalutamide, a next-generation nonsteroidal antiandrogen, with current literature queried in PubMed/Medline. A narrative review strategy describes studies from engineering of the compound through to a 5-year outlook. Expert commentary: In the phase III SPARTAN study, apalutamide significantly improved metastasis-free survival in patients with nonmetastatic castration-resistant prostate cancer - the first treatment approved by the US Food and Drug Administration for this indication. Phase III studies are under way to determine the clinical benefit of apalutamide in other disease states. Given the multiplicity of prostate cancer treatment options now available, there is a need to maximize individual patient benefit through the development and validation of predictive biomarkers of sensitivity to drugs that can be used in real time to determine the optimal sequence and combinations of treatments for patients in need.

Tumor cell heterogeneity and resistance; report from the 2018 Coffey-Holden Prostate Cancer Academy Meeting

INTRODUCTION

The 2018 Coffey-Holden Prostate Cancer Academy (CHPCA) Meeting, "Tumor Cell Heterogeneity and Resistance," was held in Los Angeles, California from June 21 to 24, 2018.

METHODS

The CHPCA Meeting is a unique, discussion-oriented scientific conference convened annually by the Prostate Cancer Foundation (PCF), which focuses on the most critical topics in need of further study to advance the treatment of lethal prostate cancer. The 6th Annual CHPCA Meeting was attended by 70 investigators and concentrated on prostate cancer heterogeneity and treatment resistance.

RESULTS

The meeting focused on topics including: recognition of tumor heterogeneity, molecular drivers of heterogeneity, the role of the tumor microenvironment, the role of heterogeneity in disease progression, metastasis and treatment resistance, clinical trials designed to target resistance and tumor heterogeneity, and immunotherapeutic approaches to target and overcome tumor heterogeneity.

DISCUSSION

This review article summarizes the presentations and discussions from the 2018 CHPCA Meeting in order to share this knowledge with the scientific community and encourage new studies that will lead to improved treatments and outcomes for men with prostate cancer.