Long-term oncological outcomes of a phase II trial of neoadjuvant chemohormonal therapy followed by radical prostatectomy for patients with clinically localised, high-risk prostate cancer

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.

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.

Neoadjuvant hormone therapy for patients with high-risk prostate cancer: a systematic review and meta-analysis

This study aimed to identify the pathological outcomes and survival benefits of neoadjuvant hormone therapy (NHT) combined with radical prostatectomy (RP) and radiotherapy (RT) administered to patients with high-risk prostate cancer (HRPCa). We searched PubMed, Embase, and the Cochrane Library for studies comparing NHT plus RP or RT with RP or RT alone, administered to patients with HRPCa. We used a random-effects model to compute risk estimates with 95% confidence intervals (CIs) and quantified heterogeneity using the I "2" statistic. Subgroup and sensitivity analyses were performed to identify potential sources of heterogeneity. We selected 16 studies. NHT before RP significantly decreased lymph node involvement (risk ratio [RR] = 0.69, 95% CI: 0.56-0.87) and increased the rates of pathological downstaging (RR = 2.62, 95% CI: 1.22-5.61) and organ-confinement (RR = 2.24, 95% CI: 1.54-3.25), but did not improve overall survival and biochemical progression-free survival (bPFS). The administration of NHT before RT to patients with HRPCa was associated with significant benefits for cancer-specific survival (hazard ratio [HR] = 0.51, 95% CI: 0.39-0.68), disease-free survival (HR = 0.51, 95% CI: 0.44-0.60), and bPFS (HR = 0.54, 95% CI: 0.46-0.64). Short-term NHT combined with RT administered to patients with HRPCa conferred significant improvements. Although the advantage of local control was observed when NHT was administered before RP, there was no significant survival benefit associated with HRPCa. Therefore, short-term NHT combined with RT is recommended for implementation in standard clinical practice but not for patients who undergo RP.

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.

Oncological outcome of neoadjuvant low-dose estramustine plus LHRH agonist/antagonist followed by extended radical prostatectomy for Japanese patients with high-risk localized prostate cancer: a prospective single-arm study

BACKGROUND

Patients with advanced high-risk prostate cancer (PCa) are prone to have worse pathological diagnoses of positive surgical margins and/or lymph node invasion, resulting in early biochemical recurrence (BCR) despite having undergone radical prostatectomy (RP). Therefore, it is controversial whether patients with high-risk PCa should undergo RP. The purpose of this study was to evaluate the efficacy of neoadjuvant chemohormonal therapy (NAC) followed by "extended" RP.

METHODS

A total of 87 patients with high-risk PCa prospectively underwent extended RP after NAC; most of the patients underwent 6 months of estramustine phosphate (EMP) 140 mg twice daily, along with a luteinizing hormone-releasing hormone agonist/antagonist. We developed our surgical technique to reduce the rate of positive surgical margins. We aimed to approach the muscle layer of the rectum by dissecting the mesorectal fascia and continuing the dissection through the mesorectum until the muscle layer of the rectum was exposed.

RESULTS

More than 1 year had elapsed after surgery in all 86 patients, with a median follow-up period of 37.7 months. The 3-year BCR-free survival was 74.9%. Multivariate Cox-regression analysis revealed that a positive core ratio of 50% or greater and pathological stage of pT3 or greater were independent predictors for BCR. About 17 of 23 cases received salvage androgen deprivation therapy and concurrent external beam radiotherapy, and showed no progression after the salvage therapies.

CONCLUSIONS

NAC concordant with extended RP is feasible and might provide good cancer control for patients with high-risk PCa.

Neoadjuvant chemohormonal therapy combined with radical prostatectomy and extended PLND for very high risk locally advanced prostate cancer: A retrospective comparative study

OBJECTIVE

Docetaxel has been shown to be an effective chemotherapy agent when combined with androgen deprivation therapy for hormone sensitive metastatic prostate cancer (CaP). Since very high risk CaP has a high rate of occult metastatic disease and early recurrence, we hypothesize that patients with very high risk locally advanced CaP may benefit from docetaxel-based neoadjuvant chemohormonal therapy (NCHT). Thus, we conducted a retrospective study to identify the outcome of these patients treated with NCHT followed by radical prostatectomy (RP).

PATIENTS AND METHODS

We retrospectively analyzed data from 177 consecutive patients who had very high risk locally advanced CaP between March 2014 and July 2017. Patients received 3 different therapies: (i) 60 men in NCHT group, (ii) 73 men in neoadjuvant hormonal therapy (NHT) group, and (iii) 44 men received immediate RP without neoadjuvant therapy (No-NT group). Surgical outcomes were analyzed and survival differences were compared by the Kaplan-Meier method.

RESULTS

The NCHT group had statistically significant higher preoperative Prostate-Specific Antigen (PSA) (P < 0.002), higher Gleason score (P < 0.002), and more advanced clinical stage (P < 0.001) than other groups. After RP, 81% (42/52) of patients in NCHT group, 73% (51/70) of patients in NHT group, and 48% (21/44) of patients in No-NT group achieved an undetectable PSA (P < 0.001). A total of 14% (6/42) patients achieving a postoperative undetectable PSA experienced biochemical recurrence in the NCHT group, with median biochemical progression-free survival (bPFS) time of 19 months; 47% (24/51) experienced biochemical recurrence in the NHT group, with median bPFS time of 13 months; 81% (17/21) experienced biochemical recurrence in the No-NT group, with median bPFS time of 9 months (P < 0.001). The median follow-up time of 3 groups was 12.5 months in the NCHT group, 18.3 months in the NHT group, and 22.8 months in the No-NT group (P = 0.01).

CONCLUSION

Despite having poorer prognostic factors, the NCHT group had better bPFS time after surgery compared to NHT and No-NT groups. Randomized controlled investigations are needed to validate these results and further follow-up is required for survival endpoints.

Consensus statements on the management of clinically localized prostate cancer from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology

OBJECTIVE

To formulate consensus statements to facilitate physician management strategies for patients with clinically localized prostate cancer (PCa) in Hong Kong by jointly convening a panel of 12 experts from the two local professional organizations representing PCa specialists, who had previously established consensus statements on the management of metastatic PCa for the locality.

METHODS

Through a series of meetings, the panellists discussed their clinical experience and the published evidence regarding various areas of the management of localized PCa, then drafted consensus statements. At the final meeting, each drafted statement was voted on by every panellist based on its practicability of recommendation in the locality.

RESULTS

A total of 76 consensus statements were ultimately accepted and established by panel voting.

CONCLUSION

Derived from the recent evidence and major overseas guidelines, along with local clinical experience and practicability, the consensus statements were aimed to serve as a practical reference for physicians in Hong Kong for the management of localized PCa.

Systematic Review of Systemic Therapies and Therapeutic Combinations with Local Treatments for High-risk Localized Prostate Cancer

CONTEXT

Systemic therapies, combined with local treatment for high-risk prostate cancer, are recommended by the international guidelines for specific subgroups of patients; however, for many of the clinical scenarios, it remains a research field.

OBJECTIVE

To perform a systematic review, and describe current evidence and perspectives about the multimodal treatment of high-risk prostate cancer.

EVIDENCE ACQUISITION

We performed a systematic review of PubMED, Embase, Cochrane Library, European Society of Medical Oncology/American Society of Clinical Oncology Annual proceedings, and clinicalTrial.gov between January 2010 and February 2018 following the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement.

EVIDENCE SYNTHESIS

Seventy-seven prospective trials were identified. According to multiple randomized trials, combining androgen deprivation therapy (ADT) with external-beam radiotherapy (EBRT) outperforms EBRT alone for both relapse-free and overall survival. Neoadjuvant ADT did not show significant improvement compared with prostatectomy alone. The role of adjuvant ADT after prostatectomy in patients with high-risk disease is still debated, with lack of data from phase 3 trials in pN0 patients. Novel androgen pathway inhibitors have been tested only in early-phase trials in addition to primary treatment. GETUG 12, RTOG 0521, and nonmetastatic subgroup of the STAMPEDE trial showed improved relapse-free survival for docetaxel in patients treated with EBRT plus ADT, although mature metastasis-free survival data are still pending. Both the SPCG-12 and the VACSP#553 trial showed no improvement in relapse-free survival for adjuvant docetaxel after prostatectomy.

CONCLUSIONS

In contrast to the clearly demonstrated survival benefits of long-term adjuvant ADT when used with EBRT, its role after prostatectomy remains unclear especially in pN0 patients. Adding docetaxel to EBRT-ADT improves relapse-free survival, with immature results on overall survival. Novel androgen receptor pathway inhibitors are currently being tested in the neoadjuvant and adjuvant setting.

PATIENT SUMMARY

Treatment of high-risk prostate cancer is based on a multimodality approach that includes systemic treatments. The best treatment or therapy combination remains to be defined.

Role of chemotherapy in prostate cancer

Chemotherapy in prostate cancer (PCa) has undergone dramatic landscape changes. While earlier studies utilized varying chemotherapy regimens which were found to be largely palliative in nature and hardly resulted in durable or meaningful responses, docetaxel resulted in the first chemotherapy agent that showed improvement in overall survival in metastatic castration-resistant prostate cancer (mCRPC). However, combination chemotherapy or any agents added to docetaxel have failed to yield incremental benefits. The improvement in overall survival as well as secondary endpoints of prostate-specific antigen (PSA) and time to recurrence when using docetaxel in the metastatic hormone-sensitive state has changed the standard of care for treatment of newly diagnosed de novo metastatic PCa. There are also promising results in locally advanced PCa and high-risk PCa in both the neoadjuvant and adjuvant settings. This review summarizes the historical as well as the more contemporary use of chemotherapeutic agents in PCa in varying states and phases of disease.

[Multimodal therapy of locally advanced prostate cancer]

Locally advanced prostate cancer (LAPCA) comprises about 5-10 % of all newly diagnosed prostate cancers and is associated with the highest prostate cancer specific mortality (approximately 8-20 %). LAPCA is defined by the presence of extraprostatic extension, seminal vesicle invasion, and bladder neck infiltration of pelvic lymph node metastases. It is evident that prognosis can only be improved by interdisciplinary multimodality treatment strategies. Adequate local staging by multiparametric MRI is one of the cornerstones for an individualized, risk-adapted treatment approach. This might consist of extended radical prostatectomy with an extended pelvic lymphadenectomy or intensity-modulated radiation therapy with androgen deprivation as the primary local therapeutic approach. Both treatment strategies may be combined with neoadjuvant or adjuvant radiation therapy or salvage surgery. Combination with neoadjuvant or adjuvant chemotherapy and new androgen receptor pathway inhibitors might also be possible. This article summarizes the current treatment strategies for LAPCA.