Lung and bone metastases from renal cell carcinoma responsive to bisphosphonates: A case report

A Case of Metastatic Collecting Duct Carcinoma Whose Massive Skull Bone Metastasis was Prominently Reossified by Gemcitabine Plus Cisplatin Chemotherapy Combined with Zoledronic Acid

The present case underwent right laparoscopic radical nephrectomy for collecting duct carcinoma (CDC). Recurrence occurred in the lung and the bone (skull and lumber vertebra) in 2011. Gemcitabine plus cisplatin (GC) chemotherapy and monthly zoledronic acid (ZA) was then started. The massive skull bone metastases were prominently reossified after several courses of the therapy. The patient received 16 courses of GC chemotherapy and monthly ZA, and pulmonary metastases and reossified skull bone metastases were stable for 23 months. Although we cannot verify the adoptive effect of ZA on the reossification, this combination may be effective for CDC bone metastases.

Bone Tumor Environment as a Potential Therapeutic Target in Ewing Sarcoma

Ewing sarcoma is the second most common pediatric bone tumor, with three cases per million worldwide. In clinical terms, Ewing sarcoma is an aggressive, rapidly fatal malignancy that mainly develops not only in osseous sites (85%) but also in extra-skeletal soft tissue. It spreads naturally to the lungs, bones, and bone marrow with poor prognosis in the two latter cases. Bone lesions from primary or secondary (metastases) tumors are characterized by extensive bone remodeling, more often due to osteolysis. Osteoclast activation and subsequent bone resorption are responsible for the clinical features of bone tumors, including pain, vertebral collapse, and spinal cord compression. Based on the “vicious cycle” concept of tumor cells and bone resorbing cells, drugs, which target osteoclasts, may be promising agents as adjuvant setting for treating bone tumors, including Ewing sarcoma. There is also increasing evidence that cellular and molecular protagonists present in the bone microenvironment play a part in establishing a favorable “niche” for tumor initiation and progression. The purpose of this review is to discuss the potential therapeutic value of drugs targeting the bone tumor microenvironment in Ewing sarcoma. The first part of the review will focus on targeting the bone resorbing function of osteoclasts by means of bisphosphonates or drugs blocking the pro-resorbing cytokine receptor activator of NF-kappa B ligand. Second, the role of this peculiar hypoxic microenvironment will be discussed in the context of resistance to chemotherapy, escape from the immune system, or neo-angiogenesis. Therapeutic interventions based on these specificities could be then proposed in the context of Ewing sarcoma.

Are bisphosphonates an indispensable tool in the era of targeted therapy for renal cell carcinoma and bone metastases?

One third of patients with metastatic renal cell carcinoma (RCC) suffer from bone metastases. Skeletal involvement in RCC is associated with the occurrence of skeletal-related events, and may negatively impact on the outcome of patients treated with systemic therapies. In patients with RCC and bone metastases, therapies that inhibit osteoclasts, as bisphosphonates and denosumab, are used as adjunct to systemic targeted therapies to prevent skeletal-related events. Data suggest that they may also improve the outcome of systemic targeted therapies. Herein we review the preclinical and clinical data on their use, as well as remaining open questions.

Current approaches to bone-targeted therapy in genitourinary malignancies

Bone metastases in patients with genitourinary cancers are associated with increased risk for skeletal-related events including pathologic fractures, spinal cord compression, and the requirement for surgery or palliative radiotherapy to bone. The nitrogen-containing bisphosphonate zoledronic acid and the monoclonal antibody against RANK, denosumab, are approved for the prevention of skeletal-related events in genitourinary cancers. These agents have different mechanisms of action and pharmacokinetic profiles, and while both are effective in reducing the risk of skeletal-related events, other clinical effects differ. There is evidence for direct and indirect anticancer activity with zoledronic acid from preclinical studies and emerging data from clinical studies suggesting an effect on patient survival. Potential anticancer mechanisms include inhibition of angiogenesis, enhanced immune surveillance via stimulation of γδ T cells, and reduction of circulating tumor cells. A synergistic effect of chemotherapy plus zoledronic acid has also been suggested. Further research is ongoing regarding the roles of these antiresorptive therapies in patients with bone metastases or at high risk for malignant spread to skeletal sites.

Zoledronic acid as a new adjuvant therapeutic strategy for Ewing's sarcoma patients

Ewing's sarcoma (ES) is the second most frequent pediatric bone tumor also arising in soft tissues (15% of cases). The prognosis of patients with clinically detectable metastases at diagnosis, not responding to therapy or with disease relapse, is still very poor. Among new therapeutic approaches, bisphosphonates represent promising adjuvant molecules to chemotherapy to limit the osteolytic component of bone tumors and to protect from bone metastases. The combined effects of zoledronic acid and mafosfamide were investigated on cell proliferation, viability, apoptosis, and cell cycle distribution of human ES cell lines differing in their p53 and p16/ink4 status. ES models were developed to reproduce both soft tissue and intraosseous tumor development. Mice were treated with 100 μg/kg zoledronic acid (two or four times per week) and/or ifosfamide (30 mg/kg, one to three cycles of three injections). ES cell lines showed different sensitivities to zoledronic acid and mafosfamide at the cell proliferation level, with no correlation with their molecular status. Both drugs induced cell cycle arrest, but in the S or G(2)M phase, respectively. In vivo, zoledronic acid had no effect on soft tissue tumor progression, although it dramatically inhibited ES development in bone. When combined with ifosfamide, zoledronic acid exerted synergistic effects in the soft tissue model: Its combination with one cycle of ifosfamide resulted in an inhibitory effect similar to three cycles of ifosfamide alone. This very promising result could allow clinicians to diminish the doses of chemotherapy.