Docetaxel, bevacizumab, and androgen deprivation therapy for biochemical disease recurrence after definitive local therapy for prostate cancer

Should androgen deprivation therapy and other systemic treatments be used in men with prostate cancer and a rising PSA post-local treatments?

Biochemical recurrence is an evolving space in prostate cancer, with increasing multidisciplinary involvement. Androgen deprivation therapy has shown proof of its value in complementing salvage radiotherapy in high-risk biochemical relapsing patients; ongoing trials aim to further refine this treatment combination. As systemic treatments, and notably next-generation androgen receptor targeted agents, have moved towards early hormone-sensitive and non-metastatic stages, the prostate specific antigen (PSA)-relapse disease stage will be undoubtedly challenged by future evidence from such ongoing clinical trials. With the use of modern imaging and newer molecular technologies, including integration of tumoral genomic profiling and liquid biopsies in risk stratification, a path towards a precision oncology-focused approach will become a reality to guide in the future decisions for patients with a diagnosis of biochemical recurrence.

Leptin Promotes Prostate Cancer Proliferation and Migration by Stimulating STAT3 Pathway

To better understand the link between obesity and prostate cancer (PC) aggressiveness, we investigate the role of leptin, an obesity associated adipokine, and its receptor (Ob-R) in PC cells migration. The migration assay (Wound-healing) was used to study the leptin impact on DU-145 and PC3 cells lines. STAT3 activation was performed by Western Blot. E-cadherin expression was studied using fluorescence microscopy and Ob-R expression in PC and benign prostatic Hyperplasia (BPH) biopsies was assessed by RT-PCR. In this study we demonstrate that high dose of leptin promotes PC cells migration and EMT transition via the stimulation of STAT3 pathway. In addition, we report that although Ob-R mRNA is expressed by ADK and BPH resections biopsies, significant higher levels were observed for ADK patients. Finally, we found a positive association between Ob-R mRNA expression and worse PC prognosis. A better understanding of the molecular processes of leptin signaling is crucial for identifying appropriate approaches for treatment of obesity-related PC patients.

A review of salvage treatment options for disease progression after radiation therapy for localized prostate cancer

Recurrence of prostate cancer after initial treatment with radiation therapy (RT) is highly dependent on pretreatment risk group and unfortunately, a proportion of patients fail primary treatment. The treatment of recurrence after primary radiation is rapidly changing with advances in imaging and it is important to distinguish those with a local failure from those with distant failure. If disease remains locally confined, salvage treatment with a variety of techniques can still provide a potential cure. Patients with distant failure are often treated with androgen deprivation, or in those with a shorter life expectancy, conservative management. In patients with a higher burden of metastatic disease, there is emerging evidence that chemotherapy and advanced androgen therapy can improve survival. We review the relevant literature on available salvage treatment options and appropriate patient selection for patients with recurrent prostate cancer after RT. We report on the efficacy and adverse effects of the currently available local salvage modalities including salvage radical prostatectomy, high dose rate and low dose rate brachytherapy, cryotherapy, high intensity focused ultrasound, and stereotactic body RT. We additionally discuss diagnosis of oligometastatic disease on imaging and current approaches to treatment with either radiation or surgery. While a full review of chemotherapy and advanced androgen therapies is beyond the scope of this article we briefly discuss their use in the treatment of newly diagnosed recurrence after radiation.

Issues and promises of bevacizumab in prostate cancer treatment

INTRODUCTION

There is general agreement that increased angiogenesis is an important factor in determining prostate cancer development and prognosis. Vascular Endothelial Growth Factor (VEGF) is thought to play a primary role in the molecular events that lead to prostate cancer progression, from androgen-dependency to castration-resistance until dissemination to the skeleton. Bevacizumab is a recombinant anti-VEGF monoclonal antibody that has exhibited clinical activity in different cancer types. Areas covered: In this review we summarize the data of clinical trials, investigating the effects of bevacizumab in prostate cancer patients. Until now, the drug has demonstrated anti-tumoral activity although with no improvements in overall survival (OS) and a wide range of alarming side effects in metastatic castration-resistant prostate cancer (mCRPC). Recently, promising results were achieved, using bevacizumab in combination with androgen deprivation therapy (ADT) in patients with recurrent prostate cancer after definitive local therapy. Expert opinion: The suboptimal efficacy of bevacizumab may relate to molecular events triggered during disease progression, such as redundancy of angiogenic factors or the interfering influence of androgens on angiogenic pathways. Further studies, using bevacizumab in combination with ADT and/or inhibitors of other key pathways on the subset of patients with low burden, hormone sensitive prostate cancer, need to be conducted.

Androgen dependent mechanisms of pro-angiogenic networks in placental and tumor development

The placenta and tumors share important characteristics, including a requirement to establish effective angiogenesis. In the case of the placenta, optimal angiogenesis is required to sustain the blood flow required to maintain a successful pregnancy, whereas in tumors establishing new blood supplies is considered a key step in supporting metastases. Therefore the development of novel angiogenesis inhibitors has been an area of active research in oncology. A subset of the molecular processes regulating angiogenesis are well understood in the context of both early placentation and tumorigenesis. In this review we focus on the well-established role of androgen regulation of angiogenesis in cancer and relate these mechanisms to placental angiogenesis. The physiological actions of androgens are mediated by the androgen receptor (AR), a ligand dependent transcription factor. Androgens and the AR are essential for normal male embryonic development, puberty and lifelong health. Defects in androgen signalling are associated with a diverse range of clinical disorders in men and women including disorders of sex development (DSD), polycystic ovary syndrome in women and many cancers. We summarize the diverse molecular mechanisms of androgen regulation of angiogenesis and infer the potential significance of these pathways to normal and pathogenic placental function. Finally, we offer potential research applications of androgen-targeting molecules developed to treat cancer as investigative tools to help further delineate the role of androgen signalling in placental function and maternal and offspring health in animal models.

A Randomized Phase II Trial of Short-Course Androgen Deprivation Therapy With or Without Bevacizumab for Patients With Recurrent Prostate Cancer After Definitive Local Therapy

PURPOSE

Patients with recurrent prostate cancer after local treatment make up a heterogeneous population for whom androgen deprivation therapy (ADT) is the usual treatment. The purpose of this randomized phase II trial was to investigate the efficacy and toxicity of short-course ADT with or without bevacizumab in men with hormone-sensitive prostate cancer.

PATIENTS AND METHODS

Eligible patients had an increasing prostate-specific antigen (PSA) of ≤ 50 ng/mL and PSA doubling time of less than 18 months. Patients had either no metastases or low burden, asymptomatic metastases (lymph nodes < 3 cm and five or fewer bone metastases). Patients were randomly assigned 2:1 to a luteinizing hormone-releasing hormone agonist, bicalutamide and bevacizumab or ADT alone, for 6 months. The primary end point was PSA relapse-free survival (RFS). Relapse was defined as a PSA of more than 0.2 ng/mL for prostatectomy patients or PSA of more than 2.0 ng/mL for primary radiation therapy patients.

RESULTS

Sixty-six patients received ADT + bevacizumab and 36 received ADT alone. Patients receiving ADT + bevacizumab had a statistically significant improvement in RFS compared with patients treated with ADT alone (13.3 months for ADT + bevacizumab v 10.2 months for ADT alone; hazard ratio, 0.47; 95% CI, 0.29 to 0.77; log-rank P = .002). Hypertension was the most common adverse event in patients receiving ADT + bevacizumab (36%).

CONCLUSION

ADT combined with bevacizumab resulted in an improved RFS for patients with hormone-sensitive prostate cancer. Long-term follow-up is needed to determine whether some patients have a durable PSA response and are able to remain off ADT for prolonged periods. Our data provide rationale for combining vascular endothelial growth factor-targeting therapy with ADT in hormone-sensitive prostate cancer.