Nine-year prostate cancer survival differences between aggressive versus conservative therapy in men with advanced and metastatic prostate cancer

Definitive local therapy for T4 prostate cancer associated with improved local control and survival

OBJECTIVES

To evaluate patients with clinical (c)T4 prostate cancer (PCa), which represent both a heterogenous and understudied population, who often present with locally advanced disease and obstructive symptoms causing significant morbidity and mortality. We analysed whether receiving definitive local therapy influenced symptomatic and oncological outcomes.

METHODS

Retrospective analysis of 154 patients with cT4 PCa treated at a single institution in 1996-2020. Systemic therapy with or without local treatment (surgery, radiotherapy [RT], or both). Uni- and multivariate analyses of associations between clinicopathological features (including obstructive symptoms) and receipt of local therapy on overall survival (OS) and disease control were done with Cox regression.

RESULTS

The median follow-up time was 5.9 years. Most patients had adenocarcinoma (88%), Gleason score 9-10 (77%), and median baseline prostate-specific antigen (PSA) of 20 ng/mL; most (54%) had metastatic cT4N0-1M1 disease; 24% regionally advanced cT4N1M0, and 22% localised cT4N0M0. Local therapies were RT (n = 44), surgery (n = 28), or both (n = nine). Local therapy was associated with improved OS (hazard ratio [HR] 0.3, P < 0.001), longer freedom from local recurrence (HR 0.39, P = 0.002), less local progression (HR 0.41, P = 0.02), fewer obstructive symptoms with progression (HR 0.31, P = 0.01), and less death from local disease (HR 0.25, P = 0.002). On multivariate, local therapy was associated with improved survival (HR 0.58, P = 0.02), and metastatic disease (HR 2.93, P < 0.001) or high-risk pathology (HR 2.05, P = 0.03) was associated with worse survival.

CONCLUSION

Definitive local therapy for cT4 PCa was associated with improved symptomatic outcomes and survival even among men with metastatic disease. Pending prospective evaluation, these findings support definitive treatment with local therapy for cT4 disease in select cases.

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.

Cytoreductive surgery in patients with oligometastatic prostate cancer. Systematic review of the scientific literature

INTRODUCTION

Interest in oligometastatic prostate cancer has spiked due to the emergence of new evidence regarding more specific and accurate imaging, and the wider use of minimally invasive techniques. Nevertheless, the optimal management of this pathology is yet to be determined.

OBJECTIVE

Assess the efficacy and safety of cytoreductive surgery in patients suffering from oligometastatic prostate cancer.

EVIDENCE GATHERING

Systematic review of the scientific literature (01/01/2010-31/12/2021) within the MedLine, Embase, Cochrane Library, Cinahl, Scopus, Spanish Healthcare Technology Assessment Agencies (AETS, Agencias de Evaluación de Tecnologías Sanitarias) and ClinicalTrials.gov databases. The keywords used were prostatectomy, prostatic neoplasm, radical prostatectomy; the free search terms were prostatectomy and oligometastatic prostate. The inclusion criteria comprised studies on patients with oligometastatic prostate cancer who had been operated on using radical cytoreductive prostatectomy.

EVIDENCE SYNTHESIS

The systematic review included 4 observational studies, 2 clinical trials, and 2 case series, of moderate quality. The results observed suggest that oligometastatic prostate cancer patients who had undergone cytoreductive prostate surgery obtained a benefit in terms of efficacy. Conversely, the majority of these studies showed a reduction in the number of localized complications, when compared to the best systemic treatments.

CONCLUSIONS

Cytoreductive surgery in this group of patients is a safe procedure that reduces the incidence of localized complications and that presents promising results with regard to survival rates. To date, the lack of prospective trials limits the use of this therapeutic option to experimental environments.

Comparing effectiveness of radical prostatectomy versus external beam radiotherapy in patients with locally advanced prostate cancer: A population-based analysis

Currently, the standard management for locally advanced prostate cancer (PCa) is still controversial. In our study, we aimed to compare the survival outcomes of radical prostatectomy (RP) versus external beam radiotherapy (EBRT).We conducted analyses with a large cohort of 38,544 patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2016). Propensity score matching, Kaplan-Meier method, and Cox proportional hazard regression were used to reduce the influence of bias and compare the overall survival (OS) and cancer specific survival (CSS). Several different sensitivity analyses including inverse probability of treatment weighting and standardized mortality ratio weighting were used to verify the robustness of the results.Totally, 33,388 men received RP and 5,156 men received EBRT with cT3-4N0M0 PCa were included in this study. According to the Kaplan-Meier curves, RP performed better in both OS and CSS compared with EBRT (P < .0001). In the adjusted multivariate Cox regression, RP also showed better OS and CSS benefits (OS: HR=0.50; 95% confidence interval [CI]: 0.46-0.54; P < .0001 and CSS: HR=0.43; 95% CI: 0.38-0.49; P < .0001). After propensity score matching, RP is still the management that can bring more survival benefits to patients. (OS: HR=0.46; 95% CI: 0.41-0.51; P < .0001 and CSS: HR = 0.41; 95% CI: 0.34-0.48; P < .0001).Our research demonstrated the significantly better survival benefits of RP over EBRT in patients with locally advanced PCa. The results of this study will provide more evidence to help clinicians choose appropriate treatment strategies.

Effect of Tumor Burden on Tumor Aggressiveness and Immune Modulation in Prostate Cancer: Association with IL-6 Signaling

Local treatment is known to improve survival in men with locally advanced prostate cancer (LAPC), but the underlying mechanisms remain unclear. In the present study, we examined the role of tumor burden in tumor aggressiveness, as well as the pathway responsible for these changes. We used human and murine prostate cancer cell lines to examine the role of tumor burden in tumor aggressiveness, as well as its correlation with cancer stem cell (CSC) marker levels and IL-6 signaling. Furthermore, 167 prostate cancer biopsy specimens were analyzed in terms of correlations of IL-6 and CD44 levels with clinical patient characteristics. Data from preclinical models showed that larger tumor burden was associated with more aggressive tumor growth associated and increased CD44 expression. Using cellular experiments and orthotopic tumor models, we showed that CD44+ prostate cancer cells have CSC-like properties, enhanced epithelial–mesenchymal transition (EMT), and a more immunosuppressive microenvironment. There was a significant correlation between IL-6 and CD44 levels based on in vitro testing of clinical samples. Blockade of IL-6/STAT3 signaling attenuated the expression of CD44, CSC-like properties, and aggressive tumor behavior in vitro and in vivo. In conclusion, CD44 expression is significantly associated with tumor aggressiveness in prostate cancer and activation of IL-6 signaling leads to a suitable microenvironment for the induction of CD44 expression. Based on our study, reduced tumor burden was associated with attenuated IL-6 signaling and augmented tumor rejection in the microenvironment, which might mediate the benefit of clinical adoption with aggressive local therapy.

Treatment of the primary tumor in metastatic prostate cancer

The cornerstone of treatment for metastatic prostate cancer patients has been conventional androgen deprivation therapy, with additional systemic therapy initiated only after castration resistance, and local therapy reserved for palliation. Compelling results from modern trials challenge this paradigm, arguing for initiating escalated hormone therapy and/or chemotherapy during the castration-sensitive disease state for many patients. Furthermore, modern radiotherapy techniques allow for local control of disease with low risk of toxicity. Finally, new PET probes with enhanced sensitivity and accuracy are likely to become a part of routine staging and will lead to an increased incidence of patients with metastatic disease at presentation, with a shift toward identification of patients with limited metastatic disease. As such, the landscape is primed for investigations aimed to explore the role of primary tumor therapy for patients with metastatic prostate cancer. We review the existing data evaluating primary tumor therapy for patients with metastatic prostate cancer and describe ongoing clinical trials testing the hypothesis that primary tumor therapy may benefit patients with metastatic prostate cancer.

Endoplasmic reticulum stress, autophagic and apoptotic cell death, and immune activation by a natural triterpenoid in human prostate cancer cells

Though the current therapies are effective at clearing an early stage prostate cancer, they often fail to treat late-stage metastatic disease. We aimed to investigate the molecular mechanisms underlying the anticancer effects of a natural triterpenoid, ganoderic acid DM (GA-DM), on two human prostate cancer cell lines: the androgen-independent prostate carcinoma (PC-3), and androgen-sensitive prostate adenocarcinoma (LNCaP). Cell viability assay showed that GA-DM was relatively more toxic to LNCaP cells than to PC-3 cells (IC₅₀ s ranged 45-55 µM for PC-3, and 20-25 µM for LNCaP), which may have occurred due to differential expression of p53. Hoechst DNA staining confirmed detectable nuclear fragmentation in both cell lines irrespective of the p53 status. GA-DM treatment decreased Bcl-2 proteins while it upregulated apoptotic Bax and autophagic Beclin-1, Atg5, and LC-3 molecules, and caused an induction of both early and late events of apoptotic cell death. Biochemical analyses of GA-DM-treated prostate cancer cells demonstrated that caspase-3 cleavage was notable in GA-DM-treated PC-3 cells. Interestingly, GA-DM treatment altered cell cycle progression in the S phase with a significant growth arrest in the G2 checkpoint and enhanced CD4 ⁺ T cell recognition of prostate tumor cells. Mechanistic study of GA-DM-treated prostate cancer cells further demonstrated that calpain activation and endoplasmic reticulum stress contributed to cell death. These findings suggest that GA-DM is a candidate for future drug design for prostate cancer as it activates multiple pathways of cell death and immune recognition.