Denosumab versus bisphosphonates for the treatment of bone metastases from solid tumors: a systematic review

DPHB inhibits osteoclastogenesis by suppressing NF-κB and MAPK signaling and alleviates inflammatory bone destruction

Overactivation of osteoclasts disrupt the delicate balance between bone-resorbing osteoclasts and bone-forming osteoblasts, resulting in development of osteoporosis and various inflammatory disorders, including rheumatoid arthritis, spondyloarthropathies, and psoriatic arthritis. While inhibiting osteoclastogenesis represents a promising therapeutic strategy, current treatments targeting the RANKL pathway (such as bisphosphonates and denosumab) are associated with severe side effects, necessitating the development of safer alternatives. We hypothesize that the compound (4E)-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (DPHB), derived from Alpinia officinarum Hance, can effectively inhibit RANKL-induced osteoclastic activity while maintaining a favorable safety profile. Through tartrate-resistant acid phosphatase (TRAP) staining and bone resorption pit assays, we demonstrate that DPHB inhibits osteoclast formation and function. Mechanistically, DPHB suppresses both NF-κB and MAPK signaling pathways while inhibiting NFATc1 activation and nuclear translocation, as evidenced by immunofluorescence staining, real-time PCR, and western blotting assays. In a LPS-induced inflammatory osteolysis mouse model, intraperitoneal administration of DPHB significantly alleviated bone destruction, confirmed through Micro-CT scanning, histological staining, and enzyme-linked immunosorbent assay (ELISA). Our findings establish DPHB as a promising osteoclast inhibitor for treating bone loss disorders through its dual suppression of osteoclastogenesis via NF-κB and MAPK signaling pathways and amelioration of inflammatory bone destruction.

Denosumab versus pamidronate in the treatment of osteolytic bone metastases secondary to breast cancer: a multi-institutional analysis

Background

Breast cancer is the most common cancer in women and most often metastasizes to the bone, resulting in skeletal-related events (SREs). Bone-modifying agents (BMAs) including denosumab, a monoclonal antibody against the receptor activator of nuclear factor kappa-b ligand (RANKL), and pamidronate, a bisphosphonate, are used to prevent these adverse events.

Methods

To analyze the efficacy of denosumab versus pamidronate, we used the TriNetX research platform and compared the outcomes of pathologic fracture, spinal cord compression, and overall 5-year survival rate between each pharmacotherapy.

Results

There was no statistical difference for an increased risk in pathological fractures (2.7% vs. 2.8%, P = 0.88), spinal cord compression (2.6% vs. 2.7%, P = 0.88), or 5-year survival rate (45.5% vs. 52.4%, P = 0.78) for the denosumab cohort versus the pamidronate cohort.

Conclusion

Since neither therapy showed an increased risk in the adverse effects measured in this study, factors such as patient preference, financial costs, and additional side effects of each medication should be taken into consideration when choosing a therapy for bone metastases in patients with breast cancer.

Bone-modifying agents for non-small-cell lung cancer patients with bone metastases during the era of immune checkpoint inhibitors: A narrative review

During the course of lung cancer progression, bone metastases occur in about 40% of patients. Common complications associated with bone metastases in lung cancer patients include musculoskeletal pain, pathologic fractures, spinal cord compression, and hypercalcemia. We discuss the efficacy of bone-modifying agents (BMAs) in reducing skeletal-related events (SREs) and improving cancer-related outcomes, particularly in patients with stage IV non-small-cell lung cancer with bone metastases. In addition, the combined effects of BMAs with radiotherapy or immunotherapy in reducing SREs in patients with lung cancer and bone metastases are explored.

Research on the Economics of Cancer-Related Health Care: An Overview of the Review Literature

We reviewed current literature reviews regarding economics of cancer-related health care to identify focus areas and gaps. We searched PubMed for systematic and other reviews with the Medical Subject Headings "neoplasms" and "economics" published between January 1, 2010, and April 1, 2020, identifying 164 reviews. Review characteristics were abstracted and described. The majority (70.7%) of reviews focused on cost-effectiveness or cost-utility analyses. Few reviews addressed other types of cancer health economic studies. More than two-thirds of the reviews examined cancer treatments, followed by screening (15.9%) and survivorship or end-of-life (13.4%). The plurality of reviews (28.7%) cut across cancer site, followed by breast (20.7%), colorectal (11.6%), and gynecologic (8.5%) cancers. Specific topics addressed cancer screening modalities, novel therapies, pain management, or exercise interventions during survivorship. The results indicate that reviews do not regularly cover other phases of care or topics including financial hardship, policy, and measurement and methods.

Drug Delivery to the Bone Microenvironment Mediated by Exosomes: An Axiom or Enigma

The increasing incidence of bone-related disorders is causing a burden on the clinical scenario. Even though bone is one of the tissues that possess tremendous regenerative potential, certain bone anomalies need therapeutic intervention through appropriate delivery of a drug. Among several nanosystems and biologics that offer the potential to contribute towards bone healing, the exosomes from the class of extracellular vesicles are outstanding. Exosomes are extracellular nanovesicles that, apart from the various advantages, are standing out of the crowd for their ability to conduct cellular communication. The internal cargo of the exosomes is leading to its potential use in therapeutics. Exosomes are being unraveled in terms of the mechanism as well as application in targeting various diseases and tissues. Through this review, we have tried to understand and review all that is already established and the gap areas that still exist in utilizing them as drug delivery vehicles targeting the bone. The review highlights the potential of the exosomes towards their contribution to the drug delivery scenario in the bone microenvironment. A comparison of the pros and cons of exosomes with other prevalent drug delivery systems is also done. A section on the patents that have been generated so far from this field is included.

Bone-modifying Agents (BMAs) in Breast Cancer

Bone-modifying agents (BMAs) are mainstays in breast cancer and prevent and treat osteoporosis in early-stage disease and reduce skeletal metastases complications in advanced disease. There is some evidence to support that BMA also prevents skeletal metastases and improves overall survival. Bone loss occurs with chemotherapy-induced ovarian failure, gonadotrophin-releasing hormone (GnRH) agonists, and aromatase inhibitors. In some women, the bone loss will be of sufficient magnitude to increase the risks of osteoporosis or fractures. Recommended steps in osteoporosis prevention or treatment include risk factor assessment, taking adequate amounts of calcium and vitamin D3, and periodic evaluations with dual-energy x-ray absorptiometry scanning. If clinically indicated by the T-scores and fracture-risk prediction algorithms treat with oral, IV bisphosphonates or subcutaneous denosumab (DEN). Zoledronic acid (ZA) or DEN reduces skeletal metastases complications, including pathological fracture, spinal cord compression, or the necessity for radiation or surgery to bone. Also, both of these drugs have the side-effect of osteonecrosis at a similar incidence. Monthly administration of ZA or DEN is standard, but several recent randomized trials show noninferiority between ZA monthly and every 3-month ZA. Every 3-month ZA is a new standard of care. Similar trials of the schedule of DEN are ongoing. ZA anticancer effect is only in postmenopausal women or premenopausal women rendered postmenopausal by GnRH agonists or bilateral oopherectomy. High-risk women, either postmenopausal or premenopausal, receiving GnRH/oopherctomy should consider adjuvant ZA. There are insufficient data to support DEN in this setting. Herein, this narrative review covers the mechanism of action of BMA, randomized clinical trials, and adverse events, both common and rare.

A Novel Sulforaphane-Regulated Gene Network in Suppression of Breast Cancer-Induced Osteolytic Bone Resorption

Bone is the most preferred site for colonization of metastatic breast cancer cells for each subtype of the disease. The standard of therapeutic care for breast cancer patients with bone metastasis includes bisphosphonates (e.g., zoledronic acid), which have poor oral bioavailability, and a humanized antibody (denosumab). However, these therapies are palliative, and a subset of patients still develop new bone lesions and/or experience serious adverse effects. Therefore, a safe and orally bioavailable intervention for therapy of osteolytic bone resorption is still a clinically unmet need. This study demonstrates suppression of breast cancer-induced bone resorption by a small molecule (sulforaphane, SFN) that is safe clinically and orally bioavailable. In vitro osteoclast differentiation was inhibited in a dose-dependent manner upon addition of conditioned media from SFN-treated breast cancer cells representative of different subtypes. Targeted microarrays coupled with interrogation of The Cancer Genome Atlas data set revealed a novel SFN-regulated gene signature involving cross-regulation of runt-related transcription factor 2 (RUNX2) and nuclear factor-κB and their downstream effectors. Both RUNX2 and p65/p50 expression were higher in human breast cancer tissues compared with normal mammary tissues. RUNX2 was recruited at the promotor of NFKB1 Inhibition of osteoclast differentiation by SFN was augmented by doxycycline-inducible stable knockdown of RUNX2. Oral SFN administration significantly increased the percentage of bone volume/total volume of affected bones in the intracardiac MDA-MB-231-Luc model indicating in vivo suppression of osteolytic bone resorption by SFN. These results indicate that SFN is a novel inhibitor of breast cancer-induced osteolytic bone resorption in vitro and in vivo.