RANK/RANK-L/OPG in patients with bone metastases treated with anticancer agents and zoledronic acid: a prospective study.

Patients with solid cancer frequently develop bone metastases (BM). Zoledronic acid (Zometa®, ZA), routinely used to treat patients with BM, acts on osteoclasts and also has antitumor properties. We aimed to assess the effect of ZA over time in novel bone turnover markers (RANK/receptor activator of nuclear factor-k B ligand (RANK-L)/ Osteoprotegerin (OPG)) and to correlate these with serum N-terminal telopeptide (NTX). The study prospectively evaluated levels of RANK, RANK-L and OPG transcripts by real-time PCR and NTX expression by ELISA in the peripheral blood of 49 consecutive patients with advanced breast, lung or prostate cancer. All patients received the standard ZA schedule and were monitored for 12 months. Median baseline values of RANK, RANK-L and OPG were 78.28 (range 7.34-620.64), 319.06 (21.42-1884.41) and 1.52 (0.10-58.02), respectively. At 12 months, the median RANK-L value had decreased by 22% with respect to the baseline, whereas median OPG levels had increased by about 96%. Consequently, the RANK-L/OPG ratio decreased by 56% from the baseline. Median serum NTX levels decreased over the 12-month period, reaching statistical significance (p < 0.0001). Our results would seem to indicate that ZA modulates RANK, RANK-L and OPG expression, thus decreasing osteoclast activity.

The role of CXCR4 in the prediction of bone metastases from breast cancer: a pilot study.

OBJECTIVE: The chemokine receptor CXCR4 is involved in tumor growth and homing of cancer cells to distant sites. The aim of our retrospective case-control study was to evaluate whether CXCR4 expression is more effective than conventional markers (estrogen receptor and HER-2) in predicting bone relapse in breast cancer. METHODS: CXCR4 expression was evaluated by immunohistochemical staining in paraffin-embedded tissue sections of primary breast cancers from 20 patients with bone metastases (BM), 10 with visceral metastases (VM) and 10 with no evidence of disease (NED) at a median follow-up of 10.5 years (range 10.1-11.8). RESULTS: Cytoplasmic CXCR4 expression was high in BM patients (45%, 95% CI 23-67), much lower in NED patients (10%, 95% CI 0-29) and negative in the VM group. CXCR4 coexpression in the nucleus and cytoplasm was observed in about half of the BM patients (45%) but never in NED or VM patients (p = 0.013). Conversely, estrogen receptor-positive and HER-2-negative status identified 80 and 95% of bone relapse patients, respectively, but did not discriminate between cases and controls. CONCLUSIONS: Our results suggest a pivotal role of CXCR4 expression as a predictor of BM in primary breast cancer. A larger study is ongoing to confirm these results.

Multidisciplinary approach to the treatment of bone metastases: Osteo-Oncology Center, a new organizational model.

AIMS AND BACKGROUND: Bone metastases are responsible for high morbidity in cancer patients. The frequency of pain and other serious complications associated with such metastases depends on the site and type of lesions and preventive therapy. The present paper aims to inform the scientific community about a new organizational health care model specifically designed for patients with bone metastases, in the hope of stimulating the creation of similar initiatives whose goals are to decrease the high morbidity of this pathology, reduce the frequency of complications, limit psychophysical distress of patients, and improve quality of life. METHODS: In January 2005, an Osteo-Oncology Center was opened in our institute to provide multidisciplinary care (19 specialists involved) for patients with bone metastases, to train physicians, and to conduct research in the field. RESULTS: In its first three years of activity, 601 multidisciplinary team consultations were made and a total of 425 patients were seen. The most frequent primary tumor site was the lung in males and the breast in females. Upon presentation at the Center, 79% of patients reported experiencing a level of pain (median pain intensity, 3.69) that interfered with normal daily activities. An anonymous questionnaire was also completed on the quality of the service provided: 75% of patients were very satisfied, 23% were satisfied, 1% responded "I don't know", and only 1% expressed dissatisfaction. CONCLUSIONS: Our preliminary results confirm the usefulness of a multidisciplinary center for the management of patients with bone metastases, especially in terms of decreasing psychophysical suffering.

RANKL: A promising circulating marker for bone metastasis response.

Bone metastases are a frequent event in patients with solid tumors. Although great advances have been made in the treatment of these patients, the identification of novel, accurate indicators of bone response would greatly facilitate the clinical management of the disease. The receptor activator of nuclear factor-κB (RANK)/RANK ligand (RANKL)/osteoprotegerin (OPG) signaling pathway is significantly involved in bone metastasis formation. The main aim of the present study was to evaluate the role of circulating RANK, RANKL and OPG levels in predicting bone response. Marker accuracy was also compared with that of the conventional tumor marker N-terminal telopeptide of type I collagen (NTX). A prospective study was performed on 49 patients with bone metastases from breast, lung and prostate cancer, who were undergoing treatment with zoledronic acid. Patients were monitored for 1 year with blood tests, clinical evaluation and instrumental exams according to the response evaluation criteria of the University of Texas M. D. Anderson Cancer Center (Houston, TX, USA) and the Positron Emission Tomography Response Criteria in Solid Tumors. Circulating RANK/RANKL/OPG transcripts and NTX levels were evaluated by reverse transcription-quantitative polymerase chain reaction and immune enzymatic assay, respectively. The baseline RANKL levels differed significantly between responders and non-responders, whereas no differences in NTX levels were observed between the two groups. Receiver operating characteristic curve evaluation for all markers revealed that RANKL was the most accurate marker, with an area under the curve of 0.74 (95% confidence interval, 0.54-0.93). In addition, RANKL, which is the target of the novel monoclonal antibody denosumab, was the most accurate predictor of bone response in the present series of patients with bone metastases. Thus, the use of RANKL as a marker could potentially improve clinical practice, as current bone response evaluation is still somewhat problematic.

Role of RANK, RANKL, OPG, and CXCR4 tissue markers in predicting bone metastases in breast cancer patients.

UNLABELLED: This is a retrospective study on 40 breast cancer patients, of which 20 have bone metastases, 10 have visceral metastases, and 10 have no evidence of disease, aimed at evaluating the role of CXCR4 and the RANK/RANKL/OPG system to predict bone metastases. CXCR4 expression, alone or in combination with RANK, identified patients destined to relapse to bone. BACKGROUND: The RANK/RANKL/OPG system is active in primary cancers such as breast, prostate, and also in their bone metastases. CXCR4 chemokine receptor is highly expressed in human breast cancer cells and is believed to facilitate the homing of tumor cells to organs such as bone that express high levels of its ligand SDF1. Our study aimed to investigate whether the analysis of these markers with an inexpensive and simple test can help to predict bone metastases in breast cancer patients. PATIENTS AND METHODS: Marker expression was evaluated by immunohistochemical staining in paraffin-embedded tissue sections of primary breast cancers from 40 individuals: 20 patients with bone metastases (BM), 10 with visceral metastases (VM; considered together as the relapsed group), and 10 with no evidence of disease (NED). RESULTS: RANKL was not detected in tumor cells. OPG- and RANK-positive tumors are found with similar frequency in NED (20%) and in relapsed patients (23% and 17%, respectively). However, in the latter subgroup, only RANK positivity was always associated with bone relapse. The frequency of CXCR4-positive tumors was three-fold higher in relapsed (30%) than in NED (10%) patients and positivity was always linked to bone metastases. Considering NED and VM patients together versus BM patients, we observed that CXCR4 expression, alone (P = .008) or in combination with RANK (P < .001), identified patients destined to relapse to bone. CONCLUSION: Our results provide the first clinical evidence to support a pivotal role of combined CXCR4 and RANK expression in predicting bone relapse.

Bone metastases detection by circulating biomarkers: OPG and RANK-L.

Osteoprotegerin (OPG) is a decoy receptor of the receptor activator of nuclear factor-κB ligand (RANK-L) and plays an important role in the formation of metastatic bone lesions. We evaluated the usefulness of circulating OPG and RANK-L for the detection of bone metastases. We enrolled 143 individuals in the study: 30 healthy donors (HD) and 113 breast cancer patients. Among patients, 49 had no evidence of disease (NEDP), 54 had bone metastases (BMP) at first diagnosis, and 10 had visceral metastases (VMP). Both transcripts were determined in peripheral blood samples using quantitative PCR. Receiver operating characteristic (ROC) curve analysis was used to calculate the diagnostic accuracy of OPG, RANK-L, CEA and CA15-3. OPG and RANK-L median values were significantly lower in BMP (median 0.5, range 0.1-5.7, p<0.001 and median 0.5, range 0.1-4.5, p=0.024, respectively) compared to NEDP (median 1.7, range 0.4-8.9 and median 0.8, range 0.2-3.8, respectively), regardless of the number and type of bone lesions or the presence of visceral metastases. The area under the ROC curve (NEDP vs. BMP) was higher for OPG (82.5, 95% CI 74.5-90.6) than for RANK-L (69.2, 95% CI 59.0-79.40). Specificity for OPG was 87.7% (95% CI 75.7-94.2) and sensitivity was 74.1% (95% CI 60.4-85.0), both values increasing when considered together with CEA and CA15-3. For VMP, OPG and RANK-L were expressed in only one patient. Our results highlight the potentially important role of circulating OPG in the diagnosis of bone metastases. A confirmatory study on a larger case series is ongoing.