The Importance of Time to Prostate-Specific Antigen (PSA) Nadir after Primary Androgen Deprivation Therapy in Hormone-Naïve Prostate Cancer Patients

Deep and Durable Prostate-specific Antigen Response to Darolutamide with Androgen Deprivation Therapy and Docetaxel, and Association with Clinical Outcomes for Patients with High- or Low-volume Metastatic Hormone-sensitive Prostate Cancer: Analyses of the Randomized Phase 3 ARASENS Study

BACKGROUND AND OBJECTIVE

Addition of darolutamide to androgen deprivation therapy (ADT) and docetaxel significantly improved overall survival (OS) in ARASENS (NCT02799602). Here we report on prostate-specific antigen (PSA) responses and their association with outcomes.

METHODS

ARASENS is an international, double-blind, phase 3 study in patients with metastatic hormone-sensitive prostate cancer (mHSPC) randomized to darolutamide 600 mg orally twice daily (n = 651) or placebo (n = 654), both with ADT + docetaxel. The proportion of patients with undetectable PSA (<0.2 ng/ml) and time to PSA progression (≥25% relative and ≥2 ng/ml absolute increase from nadir) were compared between groups in prespecified exploratory analyses. PSA outcomes by disease volume and the association of undetectable PSA with OS and times to castration-resistant prostate cancer (CRPC) and PSA progression were assessed in post hoc analyses.

KEY FINDINGS AND LIMITATIONS

The proportion of patients with undetectable PSA at any time was more than doubled with darolutamide versus placebo, at 67% versus 29% in the overall population, 62% versus 26% in the high-volume subgroup, and 84% versus 38% in the low-volume subgroup. Darolutamide delayed time to PSA progression versus placebo, with hazard ratios of 0.26 (95% confidence interval [CI] 0.21-0.31) in the overall population, 0.30 (95% CI 0.24-0.37) in the high-volume subgroup, and 0.093 (95% CI 0.047-0.18) in the low-volume subgroup. Undetectable PSA at 24 wk was associated with longer OS, with a hazard ratio of 0.49 (95% CI 0.37-0.65) in the darolutamide group, as well as longer times to CRPC and PSA progression, with similar findings in the disease volume subgroups.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Darolutamide + ADT + docetaxel led to deep and durable PSA responses in patients with high- or low-volume mHSPC. Achievement of undetectable PSA (<0.2 ng/ml) was correlated with better clinical outcomes.

PATIENT SUMMARY

For patients with metastatic hormone-sensitive prostate cancer being treated with androgen deprivation therapy and docetaxel, PSA (prostate-specific antigen) became undetectable (below 0.2 ng/ml) in 67% of those also receiving darolutamide versus 29% of patients also receiving placebo. On average, patients achieving undetectable PSA lived longer than patients with detectable PSA.

Clinical and functional outcomes for risk-appropriate treatments for prostate cancer

Objectives

To describe real-world clinical and functional outcomes in an Australian cohort of men with localised prostate cancer according to treatment type and risk category.

Subjects and methods

Men diagnosed from 2008 to 2018 who were enrolled in South Australian Prostate Cancer Clinical Outcomes Collaborative registry-a multi-institutional prospective clinical registry-were studied. The main outcome measures were overall survival, cancer-specific survival, decline in functional outcomes, biochemical recurrence and transition to active treatment following active surveillance. Multivariable adjusted models were applied to estimate outcomes.

Results

Of the 8513 eligible men, majority of men (46%) underwent radical prostatectomy (RP) followed by external beam radiation therapy with or without androgen deprivation therapy (EBRT +/- ADT) in 22% of the cohort. Five-year overall survival was above 91%, and 5-year prostate cancer-specific survival was above 97% in the low- and intermediate-risk categories across all treatments. Five-year prostate cancer-specific survival in the active surveillance group was 100%. About 37% of men with high-risk disease treated with RP and 17% of men treated with EBRT +/- ADT experienced biochemical recurrence within 5 years of treatment. Of men on active surveillance, 15% of those with low risk and 20% with intermediate risk converted to active treatment within 2 years. The decline in urinary continence and sexual function 12 months after treatment was greatest among men who underwent RP while the decline in bowel function was greatest for men who received EBRT +/- ADT.

Conclusion

This contemporary real-world evidence on risk-appropriate treatment outcomes helps inform treatment decision-making for clinicians and patients.

Deep, rapid, and durable prostate-specific antigen decline with apalutamide plus androgen deprivation therapy is associated with longer survival and improved clinical outcomes in TITAN patients with metastatic castration-sensitive prostate cancer

BACKGROUND

The first interim analysis of the phase III, randomized, double-blind, placebo-controlled, multinational TITAN study demonstrated improved overall survival (OS) and radiographic progression-free survival (rPFS) with apalutamide added to ongoing androgen deprivation therapy (ADT) in patients with metastatic castration-sensitive prostate cancer (mCSPC). The final analysis confirmed improvement in OS and other long-term outcomes. We evaluated prostate-specific antigen (PSA) kinetics and the association between PSA decline and outcomes in patients with mCSPC from TITAN.

PATIENTS AND METHODS

Patients received apalutamide (240 mg/day) or placebo plus ADT (1:1). This post hoc exploratory analysis evaluated PSA kinetics and decline in relation with rPFS (22.7 months' follow-up) and OS, time to PSA progression, and time to castration resistance (44.0 months' follow-up) in patients with or without confirmed PSA decline using a landmark analysis, Kaplan-Meier method, and Cox proportional-hazards model.

RESULTS

1052 patients (apalutamide, 525; placebo, 527) were enrolled. Best confirmed PSA declines (≥50% or ≥90% from baseline or to ≤0.2 ng/ml ) were achieved at any time during the study in 90%, 73%, and 68% of apalutamide-treated versus 55%, 29%, and 32% of placebo-treated patients. By 3 months of apalutamide treatment, best deep PSA decline of ≥90% or to ≤0.2 ng/ml occurred in 59% and 51% of apalutamide- and in 13% and 18% of placebo-treated patients, respectively. Achievement of deep PSA decline at landmark 3 months of apalutamide treatment was associated with longer OS (HR 0.35; 95% CI 0.25-0.48), rPFS (0.44; 0.30-0.65), time to PSA progression (0.31; 0.22-0.44), and time to castration resistance (0.38; 0.27-0.52) compared with no decline (P < 0.0001 for all). Similar results were observed at landmark 6 and 12 months of apalutamide treatment.

CONCLUSIONS

Apalutamide plus ADT demonstrated a robust (rapid, deep, and durable) PSA decline that was associated with improved clinical outcomes, including long-term survival.

Dynamic changes in PSA levels predict prognostic outcomes in prostate cancer patients undergoing androgen -deprivation therapy: A multicenter retrospective analysis

Background

Androgen-deprivation therapy (ADT) is used for the treatment of prostate cancer. However, the specific risk factors for the development of castration-resistant disease are still unclear. The present study sought to identify predictors of patient prognostic outcomes through analyses of clinical findings in large numbers of prostate cancer patients following ADT treatment.

Methods

Data pertaining to 163 prostate cancer patients treated at the Second Affiliated Hospital of Bengbu Medical University and Maoming People's Hospital from January 1, 2015, to December 30, 2020, were retrospectively analyzed. Dynamic changes in prostate-specific antigen (PSA) levels were regularly assessed, including both time to nadir (TTN) and nadir PSA (nPSA). Univariate and multivariate analyses were performed with Cox risk proportional regression models, while differences in biochemical progression-free survival (bPFS) were compared among groups with Kaplan-Meier curves and log-rank tests.

Results

The bPFS values over the median 43.5-month follow-up period differed significantly between patients with nPSA levels < 0.2 ng/mL and ≥ 0.2 ng/mL, being 27.6 months and 13.5 months, respectively (log-rank P < 0.001). A significant difference in median bPFS was also observed when comparing patients with a TTN ≥ 9 months (27.8 months) to those with a TTN < 9 months (13.5 months) (log-rank P < 0.001).

Conclusions

TTN and nPSA are valuable predictors of prognosis in prostate cancer patients after ADT treatment, with better outcomes evident in patients with nPSA < 0.2 ng/mL and TTN > 9 months.

Development and validation of a novel risk model in newly diagnosed de novo bone metastatic prostate cancer (M1b): a retrospective study

Background

Previous studies suggested that bone metastasis has a significant effect on the time of progression to metastatic castration-resistant prostate cancer (CRPC) for newly diagnosed de novo bone metastatic hormone-sensitive prostate cancer (mHSPC). Nevertheless, the effect of different bone metastasis sites was not fully evaluated. This study aimed to develop and validate a novel bone metastatic risk model.

Methods

We enrolled 122 patients who were newly diagnosed with de novo bone metastatic prostate cancer following primary androgen deprivation based therapy at our institution from January 2008 to June 2021. The metastatic bone sites were classified into six sites: skull; cervical, thoracic, and lumbar vertebrae; chest (ribs and sternum); pelvis; upper limbs; and lower limbs. We calculated the bone metastatic score (BMS) for each site: 0 points were assigned for non-metastasis and 1 point was assigned for metastasis. The X-tile was adopted to acquire optimal cutoff points of BMS. We defined high-risk group (HRG) as BMS ≥ 3 and low-risk group (LRG) as BMS < 3. The new bone risk stratification was validated by calculating the area under the receiver operating characteristic curve (AUC). Subsequently, the relevant clinical prognostic variables were added to construct a predictive nomogram for predicting CRPC.

Results

The median patient age was 73 years. Most patients had Gleason score ≤8 (93 cases, 76.2%). The median follow-up duration was 11.5 months (range: 2-92 months). Eighty-six patients progressed to CRPC during the follow-up. The most common bone metastatic site was the pelvis (90.2%). The median BMS was 4. Seventy-six patients had HRG, while forty-six had LRG. The 1-, 2-, and 3-year AUCs for H/LRG were 0.620, 0.754, and 0.793, respectively. The HRG was associated with earlier time to CRPC. A nomogram based on four parameters (Gleason score, H/LRG, prostate-specific antigen [PSA] nadir, and time to PSA nadir) was developed to predict CRPC. Internal validation using bootstrapping demonstrated good accuracy for predicting the CRPC (C-index: 0.727). The calibration analysis demonstrated that the model performed well.

Conclusion

We established a novel H/LRG risk model for newly diagnosed de novo bone metastatic prostate cancer, which provided evidence to support clinical decision-making.

Prognostic significance of nadir PSA value and time to nadir PSA in patients with metastatic castration-naive prostate cancer receiving first-line hormonotherapy

BACKGROUND

The current study aimed to evaluate the effect of the time duration to reach the lowest prostate-specific antigen (PSA) from the onset of first-line hormonal treatment (time to nadir PSA, TTNpsa) on survival in castration-naive metastatic prostate cancer (CN-MPC) patients.

METHODS

Eighty patients who had PSA response >80% with first-line hormonal therapy (luteinizing hormone-releasing hormone, LH-RH analog +/- bicalutamide) were included in this study.

RESULTS

Under androgen deprivation therapy (ADT), a significant positive correlation was found between TTNpsa, nadir PSA (Npsa) duration, and progression-free survival (PFS) ( p < 0.001) and overall survival (OS) ( p < 0.001). There was no correlation between TTNpsa and Npsa duration. TTNpsa and Npsa durations were independently correlated with PFS and OS. In patients with TTNpsa value ≥19 weeks, the median PFS was 126 (95% CI, 68-184) weeks compared with TTNpsa <19-week group in which the median PFS was 44 (95% CI, 26-62) weeks ( p = 0.033). In patients with TTNpsa value ≥19 weeks, the median OS was 242 (95% CI, 169-315) weeks compared with TTNpsa <19-week group in which the OS was 156 (95% CI, 89-223) weeks ( p = 0.018). The median nadir PSA value was 1 ng/mL. The median PFS was significantly longer in the patient group with ≤1 ng/mL (137 weeks, 95% CI, 50-224) compared with the group with >1 ng/mL (41 weeks, 95% CI, 34-48) ( p < 0.001). The median OS was significantly longer in the patient group with nadir PSA ≤1 ng/mL (296 weeks, 95% CI, 220-272) compared to the group with >1 ng/mL (131 weeks, 95% CI, 84-178) ( p = 0.002). In patients with nadir PSA ≤1 ng/mL ( n = 40), there was no relationship between TTNpsa and Npsa duration with both PFS and OS. However, in patients with nadir PSA >1 ng/mL ( n = 40) subgroup, there was a significant positive correlation between TTNpsa and PFS, and OS ( p < 0.001, P = 0.016, respectively).

CONCLUSION

In CN-MPC who received first-line ADT, especially in the group with the nadir PSA value >1 ng/mL, the duration of TTNpsa was positively correlated with PFS and OS.

Molecular Imaging of Neuroendocrine Prostate Cancer by Targeting Delta-Like Ligand 3

Treatment-induced neuroendocrine prostate cancer (NEPC) is a lethal subtype of castration-resistant prostate cancer. Using the 89Zr-labeled delta-like ligand 3 (DLL3) targeting antibody SC16 (89Zr-desferrioxamine [DFO]-SC16), we have developed a PET agent to noninvasively identify the presence of DLL3-positive NEPC lesions. Methods: Quantitative polymerase chain reaction and immunohistochemistry were used to compare relative levels of androgen receptor (AR)-regulated markers and the NEPC marker DLL3 in a panel of prostate cancer cell lines. PET imaging with 89Zr-DFO-SC16, 68Ga-PSMA-11, and 68Ga-DOTATATE was performed on H660 NEPC-xenografted male nude mice. 89Zr-DFO-SC16 uptake was corroborated by biodistribution studies. Results: In vitro studies demonstrated that H660 NEPC cells are positive for DLL3 and negative for AR, prostate-specific antigen, and prostate-specific membrane antigen (PSMA) at both the transcriptional and the translational levels. PET imaging and biodistribution studies confirmed that 89Zr-DFO-SC16 uptake is restricted to H660 xenografts, with background uptake in non-NEPC lesions (both AR-dependent and AR-independent). Conversely, H660 xenografts cannot be detected with imaging agents targeting PSMA (68Ga-PSMA-11) or somatostatin receptor subtype 2 (68Ga-DOTATATE). Conclusion: These studies demonstrated that H660 NEPC cells selectively express DLL3 on their cell surface and can be noninvasively identified with 89Zr-DFO-SC16.

Caffeic acid phenethyl ester induces radiosensitization via inhibition of DNA damage repair in androgen-independent prostate cancer cells

In the present study, we evaluated the radiomodulatory potential of caffeic acid phenethyl ester (CAPE), an active component of traditional herbal medicine propolis. CAPE has been identified as a potent anticancer agent in multiple cancer types and is reported to have the dual role of radioprotection and radiosensitization. However, the radiomodulatory potential of CAPE in prostate cancer (PCa), which eventually becomes radioresistant is not known. Therefore, we studied the effect of co-treatment of CAPE and gamma radiation on androgen-independent DU145 and PC3 cells. The combination treatment sensitized PCa cells to radiation in a dose-dependent manner. The radiosensitizing effect of CAPE was observed in both cell lines. CAPE enhanced the level of ionizing radiation (IR)-induced gamma H2AX foci and cell death by apoptosis. The combination treatment also decreased the migration potential of PCa cells. This was confirmed by increased expression of E-cadherin and decrease in vimentin expression. CAPE sensitized PCa cells to radiation in vitro and induced apoptosis, augmented phosphorylation of Akt/mTOR, and hampered cell migration. At the mechanistic level, co-treatment of CAPE and IR inhibited cell growth by decreasing RAD50 and RAD51 proteins involved in DNA repair. This resulted in enhanced DNA damage and cell death. CAPE might represent a promising new adjuvant for the treatment of hormone-refractory radioresistant PCa.

Comparison of Testosterone and Prostate-Specific Antigen Nadir Value between Castration Resistant Prostate Cancer and Non-Castration Resistant Prostate Cancer Patients after Androgen Deprivation Therapy - A Single Center Study in Indonesia

BACKGROUND: Prostate cancer is the second most commonly occurring cancer in adult males worldwide. Androgen deprivation therapy (ADT) is the mainstay treatment for patients with advanced prostate cancer. However, despite the low testosterone level (indicative of ADT success), most advanced prostate cancers progress into an androgen unresponsive or castrate resistant state; such cases are defined as castrate-resistant prostate cancer (CRPC) and were associated with worse outcomes and more rapid prostate cancer progression. This study aimed to compare the value of nadir testosterone level and nadir PSA in CRPC and non-CRPC patients who received ADT. AIM: This study was aimed to compare value of nadir testosterone level and nadir PSA in CRPC and non-CRPC patients who received ADT. METHODS: Prostate cancer patients receiving ADT in dr. Hasan Sadikin Bandung General Hospital in September 2018–September 2020 without previous history of CRPC and surgical castration, and prostate cancer with histopathological confirmation were included to the study. The patients prior had received complete blockade ADT with luteinizing hormone agonist (LHRH) goserelin acetate 10.8 mg injected subcutaneously per 3 months and oral anti-androgen bicalutamide 50 mg orally daily. Testosterone and PSA levels were assessed on 1st, 3rd, 6th, and 12th month. Patients then were grouped into CRPC group and non-CRPC group and further subdivided according testosterone levels (<20 and 20–500 ng/dL). Paired t-test and Chi-square test were used to analyze statistical difference (p < 0.05 deemed significant). RESULTS: Significantly higher baseline PSA (p = 0.002) and nadir PSA (p = 0.013) were found on the CRPC group. Nadir testosterone in CRPC group was higher than non-CRPC group but statistically insignificant (p = 0.849). Time to CRPC is faster in nadir testosterone 20–50 ng/dl group than in <20 ng/dl group but statistically insignificant (p = 0.837). CONCLUSION: Prostate cancer patients who had high baseline PSA and nadir PSA after ADT need a longer follow-up time and more frequent testing of the testosterone and PSA values. It can predict the incidence of CRPC and to ensure that prostate cancer patients receive adequate therapy.

Prostate-Specific Antigen Kinetics Effects on Outcomes of Low-Volume Metastatic Prostate Cancer Patients Receiving Androgen Deprivation Therapy

Background

The present study aimed to analyse factors influencing the effects of androgen deprivation therapy (ADT) in patients with newly diagnosed metastatic castration-naïve prostate cancer (mCNPC), especially in low-volume disease (LVD), according to subclassification of metastatic prostate cancer established by the CHAARTED trial.

Materials and Methods

We reviewed 648 patients with newly diagnosed mCNPC receiving ADT at Chang Gung Memorial Hospital from January 2007 to December 2016. Basic characteristics and PSA kinetics profile were subsequently evaluated.

Results

48.3% of LVD patients progressed to castration-resistant prostate cancer (mCRPC). Among them, CRPC group had significantly shorter time to PSA nadir (TTN) and faster time from PSA nadir to CRPC (TFNTC) (p < 0.001) compared to non-CRPC group. PSA doubling time (PSADT) < 4 months tended to be associated with faster disease progression and shorter overall survival (OS). Among all patients with metastatic prostate cancer, those with shorter TTN <9 months, higher nadir PSA level ≥1 ng/mL, and shorter PSADT <3 months had increased tendency for biochemical progression.

Conclusions

PSADT is an effective clinical predictor for disease progression and survival in LVD. Other PSA kinetics including TTN and TFNTC, though not the major predictors for disease progression or OS in LVD, might be the predictors for disease control status.

Tissue- and Liquid-Based Biomarkers in Prostate Cancer Precision Medicine

Worldwide, prostate cancer (PC) is the second-most-frequently diagnosed male cancer and the fifth-most-common cause of all cancer-related deaths. Suspicion of PC in a patient is largely based upon clinical signs and the use of prostate-specific antigen (PSA) levels. Although PSA levels have been criticised for a lack of specificity, leading to PC over-diagnosis, it is still the most commonly used biomarker in PC management. Unfortunately, PC is extremely heterogeneous, and it can be difficult to stratify patients whose tumours are unlikely to progress from those that are aggressive and require treatment intensification. Although PC-specific biomarker research has previously focused on disease diagnosis, there is an unmet clinical need for novel prognostic, predictive and treatment response biomarkers that can be used to provide a precision medicine approach to PC management. In particular, the identification of biomarkers at the time of screening/diagnosis that can provide an indication of disease aggressiveness is perhaps the greatest current unmet clinical need in PC management. Largely through advances in genomic and proteomic techniques, exciting pre-clinical and clinical research is continuing to identify potential tissue, blood and urine-based PC-specific biomarkers that may in the future supplement or replace current standard practices. In this review, we describe how PC-specific biomarker research is progressing, including the evolution of PSA-based tests and those novel assays that have gained clinical approval. We also describe alternative diagnostic biomarkers to PSA, in addition to biomarkers that can predict PC aggressiveness and biomarkers that can predict response to certain therapies. We believe that novel biomarker research has the potential to make significant improvements to the clinical management of this disease in the near future.

Psoralea corylifolia L. extract ameliorates benign prostatic hyperplasia by regulating prostate cell proliferation and apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoralea corylifolia L. seed (PCL), commonly known as "Poguzhi" or "BuguZhi", has been widely used to treat kidney yang deficiency in traditional Chinese medicine (TCM) where tonifying the yang deficiency is a representative understanding for treatment of hormonal deficiency disorders such as enuresis, oliguria, and prostatic diseases. Although PCL has been commonly used to treat problems of the urinary system, its efficacy against benign prostatic hyperplasia (BPH) has not yet been reported.

AIM OF THE STUDY

In the present study, we aimed to assess the in vitro and in vivo efficacy of PCL against BPH, a condition which negatively impacts quality of life in men.

MATERIALS AND METHODS

Normal human prostate cell lines, RWPE-1 and WPMY-1 cells, were stimulated with 10 nM dihydrotestosterone (DHT) to establish an in vitro BPH model. Subsequently, cells were treated with 100 or 200 μg/ml PCL, which inhibited cell proliferation without cytotoxicity, to evaluate the anti-BPH effect of PCL. Eight-week-old male Wistar rats were castrated, except for those in the control group (Con), and BPH was induced by subcutaneous injection of 10 mg/kg testosterone propionate (TP). Concurrent with daily TP injections, 5 mg/kg of finasteride (Fina) and 50 or 100 mg/kg PCL were orally administrated daily for four weeks, excluding the weekends.

RESULTS

In DHT-stimulated RWPE-1 and WPMY-1 cells, expression of androgen receptor (AR) androgen signaling-related markers such as 5α-reductase 2 (5AR2), AR, and prostate-specific antigen (PSA) was upregulated, whereas 100 or 200 μg/ml of PCL treatment downregulated these markers. Furthermore, PCL significantly reduced the mRNA expression of anti-apoptotic genes and increased the mRNA expression of pro-apoptotic gene. In vivo, administration of PCL reduced prostate size and weight in TP-induced BPH rats. Moreover, histological alterations in epithelium thickness were significantly restored by the administration of PCL. Immunohistochemical analysis revealed increased expression of AR and proliferating cell nuclear antigen (PCNA) in TP-induced BPH prostates; these changes were suppressed by administration of 50 or 100 mg/kg PCL.

CONCLUSIONS

We demonstrated the effect of PCL against BPH, mediated by the regulation of prostate cell proliferation and apoptosis, in DHT-stimulated normal human prostate cell lines and TP-induced BPH rats. These findings suggest that PCL could be a potential therapeutic agent against BPH.

Heterogeneous induction of an invasive phenotype in prostate cancer cells by coculturing with patient-derived fibroblasts

Prostate cancer (PCa) cells frequently invade the surrounding stroma, leading to heterogeneous formation of structural atypia. The surrounding stroma contains multiple functionally diverse populations of fibroblasts that trigger numerous changes in PCa cells including motility. Thus, we hypothesized that direct or indirect contact of PCa cells with fibroblasts determines an invasive phenotype in PCa cells. We investigated the effects of 10 different patient-derived fibroblast lines on the three-dimensional (3D) morphogenesis of PCa cells growing on a viscous substrate in vitro. When grown alone, all 10 patient-derived fibroblast lines clumped on the viscous substrate, whereas the human androgen-sensitive PCa cell line LNCaP did not. Cocultures of LNCaP cells with seven of the patient-derived fibroblast lines (PrSC, pcPrF-M5, pcPrF-M7, pcPrF-M23, pcPrF-M24, pcPrF-M28, and pcPrF-M31) formed a thick fibroblast layer that resembled human prostate stromal structures. In contrast, cocultures of LNCaP cells with the remaining three fibroblast lines (NPF-M13, pcPrF-M10, and pcPrF-M26) did not form a thick fibroblast layer. Of the seven fibroblast lines that caused thick layer formation, four patient-derived fibroblast lines (PrSC, pcPrF-M5, pcPrF-M28, and pcPrF-M31) induced an invasive phenotype in LNCaP cells with a cord-like infiltrating growth pattern, whereas the other three fibroblast lines (pcPrF-M7, pcPrF-M23, and pcPrF-M24) induced no or a very weak invasive phenotype. Using cell culture inserts, none of the four patient-derived fibroblast lines that induced an invasive phenotype (PrSC, pcPrF-M5, pcPrF-M28, and pcPrF-M31) affected CDH1 mRNA expression in LNCaP cells; yet, two patient-derived fibroblast lines (pcPrF-M5 and pcPrF-M28) increased CDH2 mRNA expression in LNCaP cells, whereas the other two fibroblast lines (PrSC and pcPrF-M31) did not. These results suggest that the existence of multiple functionally diverse populations of fibroblasts in PCa tissue may be responsible for the diversity in PCa cell invasion, leading to heterogeneous formation of structural atypia.

PSA Kinetics as Prognostic Markers of Overall Survival in Patients with Metastatic Castration-Resistant Prostate Cancer Treated with Abiraterone Acetate

Background

Abiraterone acetate (AA) is widely used in the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). However, a significant percentage of patients will still progress, highlighting the need to identify patients more likely to benefit from AA. Parameters linked to prostate-specific antigen (PSA) kinetics are promising prognostic markers. We have examined clinical and PSA-related factors potentially associated with overall survival (OS) in patients treated with AA.

Methods

Between 2011 and 2014, 104 patients with mCRPC treated with AA after progression to docetaxel at centers of the Catalan Institute of Oncology were included in this retrospective study. Patients were assessed monthly. Baseline characteristics and variables related to PSA kinetics were included in univariate and multivariate analyses of OS.

Results

Median OS was 16.4 months (range 12.4-20.6) for all patients. The univariate analysis identified the following baseline characteristics as significantly associated with OS: ECOG PS, location of metastases, time between starting androgen deprivation therapy and starting AA, time between stopping docetaxel treatment and starting AA, neutrophil-lymphocyte ratio (NLR), alkaline phosphatase levels, and PSA levels. Factors related to PSA kinetics associated with longer OS were PSA response >50%, early PSA response (>30% decline at four weeks), PSA decline >50% at week 12, PSA nadir <2.4ng/mL, time to PSA nadir >140 days, the combination of PSA nadir and time to PSA nadir, and low end-of-treatment PSA levels. The multivariate analysis identified ECOG PS (HR 37.46; p<0.001), NLR (HR 3.7; p<0.001), early PSA response (HR 1.22; p=0.002), and time to PSA nadir (HR 0.39; p=0.002) as independent prognostic markers.

Conclusion

Our results indicate an association between PSA kinetics, especially early PSA response, and outcome to AA after progression to docetaxel. Taken together with other factors, lack of an early PSA response could identify patients who are unlikely to benefit from AA and who could be closely monitored with a view to offering alternative therapies.

EGFR-upregulated LIFR promotes SUCLG2-dependent castration resistance and neuroendocrine differentiation of prostate cancer

Neuroendocrine (NE) differentiation is a well-recognized phenotypic change of prostate cancer after androgen deprivation therapy (ADT), and it ultimately develops into an aggressive subset of this disease. However, the contribution of signaling pathways that lead to metabolic disorders and NE differentiation of prostate cancer remains unclear. In this study, we identified that ADT induced upregulation of the succinate-CoA ligase GDP-forming beta subunit (SUCLG2), which regulates succinate metabolism and NE differentiation of prostate cancer. We demonstrated a connection that upregulation of epidermal growth factor receptor (EGFR)-leukemia inhibitory factor receptor (LIFR) signaling induced SUCLG2 expression in prostate cancer cells. The LIFR is upregulated by nuclear EGFR, which acts as a transcriptional regulator, directly binds to the LIFR promoter, and drives NE differentiation and glycolysis of prostate cancer. LIFR upregulation is associated with SUCLG2, which increased succinate synthesis and enzymatic activities of mitochondrial nucleoside diphosphate kinase (NDPK) in prostate cancer cells. Knockdown of SUCLG2 suppressed NE differentiation in cultured cells and reduced prostate tumor growth in a xenograft model. Analysis of prostate tissue samples showed increased intensity of nuclear EGFR associated with the LIFR and SUCLG2 in castration-resistant prostate cancer tumors. Our study provides a mechanism whereby ADT upregulates EGFR-LIFR signaling that activates SUCLG2, which subsequently stimulates the metabolic changes associated with NE differentiation and aggressive prostate cancer phenotype.

Recent scenario of long non-coding RNAs as a diagnostic and prognostic biomarkers of prostate cancer

Prostate cancer (CaP) is a leading cause of cancer deaths in the worldwide with broad range of clinical manifestations ranging from relatively indolent to aggressive metastasis. Altered expression of many circulating long non-coding RNAs (lncRNAs), known to have role in tumorigenesis and metastasis, have already been reported in CaP patients. These lncRNAs modulate CaP pathogenesis by modulating multiple genes and thus altering metabolic pathways. Sustained androgen receptor (AR) signaling is one such key feature of castration-resistant prostate cancer, a CaP stage that has unmet need of accurate diagnostic and prognostic tools, that is affected by lncRNAs. In this review, we have discussed the emerging functions and associations of AR lncRNAs in CaP and highlighted their potential implications in cancer diagnostics and therapeutics. Further, extensive literature analysis in this article indicates that there is an immediate unmet need in the translational approach toward the hitherto identified AR lncRNAs. The characterization of AR lncRNAs involved in CaP is not exhaustive and adequate validation studies are still required to corroborate the present results that would be the impending future of basic research setting into clinical practice.

Ras and Wnt Interaction Contribute in Prostate Cancer Bone Metastasis

Prostate cancer (PCa) is one of the most prevalent and malignant cancer types in men, which causes more than three-hundred thousand cancer death each year. At late stage of PCa progression, bone marrow is the most often metastatic site that constitutes almost 70% of metastatic cases of the PCa population. However, the characteristic for the osteo-philic property of PCa is still puzzling. Recent studies reported that the Wnt and Ras signaling pathways are pivotal in bone metastasis and that take parts in different cytological changes, but their crosstalk is not well studied. In this review, we focused on interactions between the Wnt and Ras signaling pathways during each stage of bone metastasis and present the fate of those interactions. This review contributes insights that can guide other researchers by unveiling more details with regard to bone metastasis and might also help in finding potential therapeutic regimens for preventing PCa bone metastasis.