Analgesic efficacy of zoledronic acid and its effect on functional status of prostate cancer patients with metastasis

Use of bisphosphonates and other bone supportive agents in the management of prostate cancer-A UK perspective

AIM

To explore the practice and views of uro-oncologists in the UK regarding their use of bone supportive agents in patients with prostate cancer.

METHODS

An expert-devised online questionnaire was completed by members of the British Uro-oncology Group (BUG).

RESULTS

Of 160 uro-oncologists invited, 81 completed the questionnaire. Approximately 70% of respondents never use a bone supportive agent in patients with metastatic hormone-naïve prostate cancer on androgen deprivation therapy (ADT). However, use was more frequent in men with metastatic castration-resistant prostate cancer, from first-line treatment onwards. The majority of uro-oncologists do not use a bone supportive agent to prevent skeletal-related events in men with non-metastatic disease unless the individual patient is at an increased risk of osteoporosis. In men with more advanced disease, respondents would use an oral or intravenous (IV) bisphosphonate in 41% and 61% of patients, respectively. Zoledronic acid is the first-choice bone supportive treatment in 77% of cases, with the lack of clinical data cited as a barrier to use for other IV bisphosphonates. Local guidelines also have a significant influence on the use of bone supportive agents, especially with respect to denosumab. Bone mineral density measurement is conducted in approximately 40% of men with ADT exposure of 2 years or longer, or those with metastatic prostate cancer.

CONCLUSION

Uro-oncologists in the UK generally do not use bone supportive agents for men with metastatic hormone-naïve prostate cancer or those with non-metastatic disease. However, increasing the duration of ADT and the presence of castration-resistant metastatic prostate cancer increases use.

The role of glucose-6-phosphate dehydrogenase in adipose tissue inflammation in obesity

Obesity is closely associated with metabolic diseases including type 2 diabetes. One hallmark characteristics of obesity is chronic inflammation that is coordinately controlled by complex signaling networks in adipose tissues. Compelling evidence indicates that reactive oxygen species (ROS) and its related signaling pathways play crucial roles in the progression of chronic inflammation in obesity. The pentose phosphate pathway (PPP) is an anabolic pathway that utilizes the glucoses to generate molecular building blocks and reducing equivalents in the form of NADPH. In particular, NADPH acts as one of the key modulators in the control of ROS through providing an electron for both ROS generation and scavenging. Recently, we have reported that glucose-6-phosphate dehydrogenase (G6PD), a rate-limiting enzyme of the PPP, is implicated in adipose tissue inflammation and systemic insulin resistance in obesity. Mechanistically, G6PD potentiates generation of ROS that augments pro-inflammatory responses in adipose tissue macrophages, leading to systemic insulin resistance. Here, we provide an overview of cell type- specific roles of G6PD in the regulation of ROS balance as well as additional details on the significance of G6PD that contributes to pro-oxidant NADPH generation in obesity-related chronic inflammation and insulin resistance.

Phase II trial of zoledronic acid combined with androgen-deprivation therapy for treatment-naïve prostate cancer with bone metastasis

BACKGROUND

The efficacy of zoledronic acid in patients with treatment-naïve prostate cancer is unclear. We conducted a phase II study to investigate the benefits of combined zoledronic acid and androgen deprivation therapy in treatment-naïve prostate cancer with bone metastasis. The primary endpoint was skeletal-related event-free survival at 24 months.

METHODS

Subjects were treatment-naïve patients with histologically confirmed adenocarcinoma of the prostate and radiological evidence of bone metastasis. Treatment consisted of bicalutamide 80 mg daily, goserelin acetate 10.8 mg every 12 weeks, and zoledronic acid 4 mg every 4 weeks. Zoledronic acid was continued for 24 months.

RESULTS

Of the patients enrolled between July 2008 and April 2010, 52 were included in the analyses. The median age of the patients was 72 years. The median baseline prostate-specific antigen level was 249.4 ng/mL. The median follow-up period was 33.3 months. The 24-month skeletal-related event-free survival rate was 84.4 % (95 % confidence interval 71.2-91.9). The median time to prostate-specific antigen progression was 25.9 months (95 % confidence interval 14.7-36.3). The median overall survival time was not reached. Improvement in pain or maintenance of no pain during the first 12 weeks was observed in 70 % of patients and the extent of bone disease was decreased in 10 % of patients at 12 months. Grade 3 osteonecrosis of the jaw was observed in three patients (5.8 %).

CONCLUSION

Zoledronic acid concomitant with androgen deprivation therapy as initial treatment in patients with treatment-naïve prostate cancer with bone metastasis resulted in an encouraging skeletal-related event-free survival rate at 24 months.