Cancer Stemness/Epithelial-Mesenchymal Transition Axis Influences Metastasis and Castration Resistance in Prostate Cancer: Potential Therapeutic Target.

Prostate cancer (PCa) is a leading cause of cancer death in men, worldwide. Mortality is highly related to metastasis and hormone resistance, but the molecular underlying mechanisms are poorly understood. We have studied the presence and role of cancer stem cells (CSCs) and the Epithelial-Mesenchymal transition (EMT) in PCa, using both in vitro and in vivo models, thereby providing evidence that the stemness-mesenchymal axis seems to be a critical process related to relapse, metastasis and resistance. These are complex and related processes that involve a cooperative action of different cancer cell subpopulations, in which CSCs and mesenchymal cancer cells (MCCs) would be responsible for invading, colonizing pre-metastatic niches, initiating metastasis and an evading treatments response. Manipulating the stemness-EMT axis genes on the androgen receptor (AR) may shed some light on the effect of this axis on metastasis and castration resistance in PCa. It is suggested that the EMT gene SNAI2/Slug up regulates the stemness gene Sox2, and vice versa, inducing AR expression, promoting metastasis and castration resistance. This approach will provide new sight about the role of the stemness-mesenchymal axis in the metastasis and resistance mechanisms in PCa and their potential control, contributing to develop new therapeutic strategies for patients with metastatic and castration-resistant PCa.

Metastasic Prostate Cancer: Predictive Factors of Earlier Progression to Castration-Resistance.

INTRODUCTION: Prostate cancer (PCa) can progress to the lethal phenotype of metastatic castration resistance (mCRPC), either from initially localized disease or de novo metastatic cancer. New drugs improving overall survival are now the cornerstone of treatment. Nevertheless, there are no defined sequences or established timing to initiate or discontinue treatments; besides, not all patients end in CRPC or reach this stage at the same time. OBJECTIVE: To evaluate characteristics of patients who progress to mCRPC and establish an association with time to mCRPC diagnosis. MATERIAL AND METHODS: Retrospective, descriptive and observational study of 35 mCRPC patients, performed from 2013 to 2017. Variables analyzed were age, Gleason score and prostate-specific antigen (PSA) at diagnosis, initial stage, response time to androgen deprivation therapy (ADT), PSA nadir on ADT and time until mCRPC progression. Statistical analysis comparing variables with time to mCRPC diagnosis was performed. RESULTS: Average age at diagnosis was 68.9 years; PSA values were classified into 3 categories: <20 ng/ml, 20-50 and >50. Gleason score was 7 in 50%, and 8-9 in the rest. Tumor was initially localized in 46% of the patients and metastatic in the rest. PSA nadir on ADT was <1 ng/ml in 67%. Average time to androgen deprivation: 5.5 years, time to mCRPC diagnosis: 6.9 years. Significant associations between time to mCRPC and time of androgen deprivation, PSA nadir during ADT and stage at diagnosis were found. CONCLUSION: Response time to ADT <1 year, PSA nadir value >5 ng/ml during treatment and metastatic stage at diagnosis were associated with earlier progression to mCRPC.

Experience of bipolar androgen therapy (BAT) in Argentinian oncology centres.

Background: Previous studies with bipolar androgen therapy (BAT) have shown clinical activity in metastatic Castration Resistant Prostate Cancer (mCRPC) as well as the potential to re-sensitise prostate cancer cells to prior androgen receptor-targeted agents. None of these studies had tested BAT after chemotherapy. In this study, we gathered real-world evidence from three centres in Argentina where BAT is being used in castration-resistant prostate cancer (CRPC), not only prior to chemotherapy but also after several lines of treatment. Materials and methods: This retro-prospective nonrandomised multicentre cohort study included patients with mCRPC, who received BAT in different scenarios defined by the treating physician at three centres in Argentina. Results: A total of 21 asymptomatic patients with mCRPC were included. There was a median of two lines before BAT, with nine patients (42.8%) receiving three or more lines, and 13 patients (61.9%) receiving chemotherapy previously. Previous lines included next-generation hormonal agents (NHA) in 100% (abiraterone 33.3% and enzalutamide 71.4%), chemotherapy in 61.9%, Radium-223 in 47.6% and others in 4.8%. The progression free survival (PFS) after BAT was 3.5 months (95% CI: 3.06-7.97). PSA50 response rate (RR) was 28.5% and the overall RR was 14.3%. Of the 17 patients who had disease progression, 9 had a rechallenge to NHA, achieving a 55% RR, 6 received other treatment (chemotherapy in 5 and 177Lu-PSMA in 1) with a 66% RR and 2 best supportive care. The PFS2, calculated after the initiation of BAT in the 15 patients who received further therapy, was 7.93 months (95% CI: 6.73-NR). Treatment was overall well tolerated, with only two patients requiring hospitalisation and treatment interruption due to worsening pain. Conclusion: To the authors' knowledge, this is the first publication of BAT in later lines of therapy in mCRPC. BAT showed clinical activity in this scenario. Our data supports that BAT may play a role in CRPC re-sensitisation after multiple treatment lines.

Pro-angiogenic effect of PC-3 exosomes in endothelial cells in vitro.

The progression to a castration-resistant prostate cancer can occur after treatment with androgen deprivation therapy, resulting in poor prognosis and ineffective therapy response. Hormone dependence transition has been associated with increased tumor vascularization. Considering that exosomes are important components in communication between tumor cells and the microenvironment, we examined the angiogenic potential of exosomes released from Pca cell lines with distinctive profiles of androgen response through exosomes isolation, microscopy and uptake, functional assays follow up by microarray, RT-qPCR and bioinformatics analysis. HUVEC cells treated with PC-3 exosomes (androgen independent) showed increased invasion and tube formation ability. In order to identify microRNAs (miRNAs) related to the angiogenic response, the characterization of exosomal miRNA profile was performed. As result we suggest that the miR-27a-3p could be involved in the pro-angiogenic effect of PC-3 exosomes.

Prostate Cancer Progression: as a Matter of Fats.

Advanced prostate cancer (PCa) represents the fifth cause of cancer death worldwide. Although survival has improved with second-generation androgen signaling and Parp inhibitors, the benefits are not long-lasting, and new therapeutic approaches are sorely needed. Lipids and their metabolism have recently reached the spotlight with accumulating evidence for their role as promoters of PCa development, progression, and metastasis. As a result, interest in targeting enzymes/transporters involved in lipid metabolism is rapidly growing. Moreover, the use of lipogenic signatures to predict prognosis and resistance to therapy has been recently explored with promising results. Despite the well-known association between obesity with PCa lethality, the underlying mechanistic role of diet/obesity-derived metabolites has only lately been unveiled. Furthermore, the role of lipids as energy source, building blocks, and signaling molecules in cancer cells has now been revisited and expanded in the context of the tumor microenvironment (TME), which is heavily influenced by the external environment and nutrient availability. Here, we describe how lipids, their enzymes, transporters, and modulators can promote PCa development and progression, and we emphasize the role of lipids in shaping TME. In a therapeutic perspective, we describe the ongoing efforts in targeting lipogenic hubs. Finally, we highlight studies supporting dietary modulation in the adjuvant setting with the purpose of achieving greater efficacy of the standard of care and of synthetic lethality. PCa progression is "a matter of fats", and the more we understand about the role of lipids as key players in this process, the better we can develop approaches to counteract their tumor promoter activity while preserving their beneficial properties.

Experiencia inicial en seguridad, tolerancia y adherencia al uso de docetaxel en pacientes con cáncer de próstata castración sensibles en un centro oncológico nacional / Initial experience in safety, tolerance and adherence to the use of docetaxel in patients with sensitive castration prostate cancer in a national cancer center

INTRODUCCIÓN: El cáncer de próstata (PC) es una enfermedad de alta incidencia y prevalencia (90/100.00 habitantes) y constituye la segunda causa por muerte oncológica en hombres, fenómeno que acontece en su fase metastásica (mPC). El tratamiento estándar en esta etapa corresponde a la terapia de deprivación androgénica (TDA) que produce una respuesta oncológica favorable en términos de descenso del PSA y estabilización y/o regresión de las metástasis. Ésta primera etapa (castración sensible) dura en promedio 2 a 3 años, tras lo cual ocurre una independización tumoral del estímulo androgénico, fenómeno conocido como castración-resistencia (mCRPC). En esta etapa la quimioterapia (QMT) con docetaxel prolonga la sobrevida aproximadamente 4 meses, lo cual en conjunto con otros tratamientos de segunda línea (abiraterona, enzalutamida, etc.) logra alcanzar una sobrevida media desde el diagnostico de mCRPC de 24 meses. Diversos estudios (CHAARTED y STAMPEDE) han demostrado que el inicio de docetaxel junto con TDA en pacientes con mPC castración-sensible (mCSPC) prolongan sobrevida global hasta 17 meses, especialmente si hay alto volumen de enfermedad. El objetivo del estudio es describir las características clínicas, la respuesta oncológica inicial y el perfil de efectos adversos de pacientes con mCSPC sometidos a docetaxel. MATERIALES Y MÉTODOS: Estudio retrospectivo descriptivo entre mayo 2014 a Julio 2017. Se incluyeron pacientes ng/ml (rango 10,8 - 5550) y mediana de seguimiento 6 meses (rango 3 ­ 20). Catorce pacientes tenían Gleason > 8, 18 eran M+ de los cuales 9 eran viscerales. Solo uno recibió tratamiento local previo. La mediana de inicio de QMT fue 3,1 (0 ­ 6,1) meses post inicio TDA.Dieciséis pacientes completaron docetaxel y 4 siguen en curso. No hubo suspensión de QMT por efectos adversos. Los más frecuentes fueron diarrea (8/20), neuropatía (5/20) y vómitos (2/20). La mayoría fue grado 1 y solo tres presentaron complicaciones grado 3 (diarrea, leucopenia y trombocitopenia). No hubo complicaciones grado 4 -5. Diez pacientes alcanzaron un antígeno < 2 ng/ml a las 12 semanas post tratamiento y 7 presentaron recidiva bioquímica durante el seguimiento. Uno tuvo respuesta imagenológica completa, 10 respuesta parcial, 7 estabilidad y 2 mostraron progresión. CONCLUSIONES: El uso de Docetaxel en mCSPC es seguro, presenta escasos efectos adversos (la mayoría de intensidad leve) que no motivan suspensión. El tratamiento con docetaxel exhibe una respuesta prometedora en términos de control de PSA, sin embargo se requiere mayor seguimiento de esta cohorte para evaluar impacto en sobrevida. con mCSPC con enfermedad de alto volumen (metástasis óseas extra-axiales, viscerales o Gleason 9-10) y ECOG 0-1. Los pacientes recibieron TDA y seis ciclos de Docetaxel. Se registraron datos demográficos, clínicos, histopatológicos, PSA, imagenológicos (RECIST V1.1) y toxicidad (NCI CAE 4.0) RESULTADOS: Se incluyeron 20 pacientes, mediana de edad 63 años (rango 49 ­ 75). Mediana PSA de ingreso 267,5 ng/ml (rango 10,8 - 5550) y mediana de seguimiento 6 meses (rango 3 ­ 20). Catorce pacientes tenían Gleason > 8, 18 eran M+ de los cuales 9 eran viscerales. Solo uno recibió tratamiento local previo. La mediana de inicio de QMT fue 3,1 (0 ­ 6,1) meses post inicio TDA.Dieciséis pacientes completaron docetaxel y 4 siguen en curso. No hubo suspensión de QMT por efectos adversos. Los más frecuentes fueron diarrea (8/20), neuropatía (5/20) y vómitos (2/20). La mayoría fue grado 1 y solo tres presentaron complicaciones grado 3 (diarrea, leucopenia y trombocitopenia). No hubo complicaciones grado 4 -5. Diez pacientes alcanzaron un antígeno < 2 ng/ml a las 12 semanas post tratamiento y 7 presentaron recidiva bioquímica durante el seguimiento. Uno tuvo respuesta imagenológica completa, 10 respuesta parcial, 7 estabilidad y 2 mostraron progresión. CONCLUSIONES: El uso de Docetaxel en mCSPC es seguro, presenta escasos efectos adversos (la mayoría de intensidad leve) que no motivan suspensión. El tratamiento con docetaxel exhibe una respuesta prometedora en términos de control de PSA, sin embargo se requiere mayor seguimiento de esta cohorte para evaluar impacto en sobrevida.(AU)

INTRODUCTION: Prostate cancer is a disease with high incidence and prevalence (90/100.000 habitants) and the second cause of cancer related death in men. Standard treatment in this setting is androgen-deprivation therapy (TDA), which causes decrease in PSA levels and stabilization or regression of metastatic lesions. Responses in castration sensitive phase last in average 3 years, after which tumor is described to become independent from the androgenic stimuli, reaching a castration-resistance (mCRPC) state. At this point chemotherapy with docetaxel as well as second line treatments (abiraterone, enzalutamide, among others)have shown to improve survival in 4 months with mean survival from diagnosis of mCRPC of 24 months. Studies including CHAARTED and STAMPEDE have demonstrated that early treatment with docetaxel with ADT in patients with mCSPC prolongs overall survival, especially if high volume disease exists. This study describes the clinical characteristics, initial oncologic response and side effects profile of mCSPC treated with Docetaxel plus ADT. MATERIALS AND METHODS: Descriptive Retrospective study from May 2014 to July 2017. mCSPC patients with high volume disease (extra axial bone metastasis, visceral metastasis or Gleason 9-10) and ECOG 0-1 were included. Patients received ADT and 6 cycles of Docetaxel. Demographic, clinical and histopathological characteristicswere registered, together with PSA, radiologic data (RECIST V1.1) and toxicity (NCI CAE 4.0). RESULTS: 20 patients were included, median age 63 years (49-75 range). Median initial PSA 267,5 ng/ml (10,8-5550 range), and median follow up 6 months (3-20 range). Fourteen patients had Gleason > 8, 18presented bone metastasis and 9/14 viscerametastasis. Only 1 patient received previous local treatment. Median initialtime to initiation of Docetaxel post ADT was 3,1 (0-6,1) months.Sixteen patients completed docetaxel and 4 are still receiving treatment. There was no chemotherapy suspension due side effects. Most frequent side effects were diarrhea (8/20), neuropathy (5/20) and vomiting (2/20). Most were grade 1 and three patients presented grade 3 side effects (diarrhea, leukopenia and thrombocytopenia). No grade 4-5 side effects were reported.Ten patients reached PSA< 2 ng/m after 12 weeks of treatment, and 7 had biochemical relapse during follow up. One had complete radiologic response, 10 partial response, 7 remained stable and 2 showed progression of disease. CONCLUSION: The use of docetaxel in mCSPC isassociated to few side effects and none requiredsuspension of treatment. Treatment with Docetaxel exhibits promising results in terms of decrease in PSA, however longer follow up and greater number of patients are required to report benefits in overall survival.(AU)

Stereotactic body radiation therapy (SBRT) delays the emergence of castration resistance in patients with oligometastatic prostate cancer.

PURPOSE: To investigate whether bon e metastases-directed stereotactic body radiation therapy (SBRT) delays the emergence of castration resistance in patients with oligometastatic prostate cancer (OPC). METHODS AND MATERIAL: OPC is usually managed with androgen deprivation therapy (ADT). Migration to castration-resistant prostate cancer will inevitably occur in the majority of these patients. There are several strategies aimed to delay the emergence of castration resistance including intermittent ADT, second generation antiandrogens (abiraterone, enzalutamide) or metastases-directed SBRT. The present report describes two cases of patients with OPC that received SBRT 24 Gy/3Rx to the solitary bony lesion after ADT failure. RESULTS: Both cases showed complete and durable biochemical response for 13 and 17 months, respectively. CONCLUSIONS: SBRT can be used to delay the emergence of castration resistance and the need for systemic therapy when used after ADT failure.