19659 Background: Bone metastases produce an imbalance in osteoblast and osteoclast activity. While metastases from prostate cancer are osteoblastic, metastases from breast cancer may be osteolytic, osteoblastic or mixed. The wnt/frizzled pathway is involved in maturation of osteoblasts and in adult bone homeostasis. We explored the wnt antagonists dickkopf (DKK1) and frizzled related protein (FRP) as potential biomarkers in bone metastasis after ZA treatment. Methods: This is a pilot cohort study in bisphosphonate naive breast and prostate cancer patients with bone metastases. Cancer therapy was not specified. Patients received 2 monthly doses of ZA 4 mg IV. Pre- and post-treatment (day 60) sera were collected for measurement of FRP and DKK1, along with IL-6, calcium, creatinine and bone-specific alkaline phosphatase (BAP, a marker of osteoblast activity). Primary endpoint: mean change in FRP and DKK1; Secondary endpoints: correlation of biomarkers with each other and comparison of breast vs. prostate cancer patients. Biomarkers were measured using standard ELISA assays. Statistics: comparison of means = student t-test, correlation coefficients = Pearson. Results: Mature data from 14 patients are reported here, 9 with breast and 5 with prostate cancer. Mean age = 61 years (range 42–89). Two breast cancer patients were premenopausal. One prostate and 3 breast cancer patients received chemotherapy; all others were treated hormonally. After ZA, calcium decreased in all patients (p = 0.09). BAP decreased in all but 1 breast and 1 prostate cancer patient (mean decrease 20.0, p = 0.16). IL-6 was undetectable in most patients. FRP decreased in all but 4 patients (mean decrease 6.2, p = 0.13). There was no discernable pattern for DKK1. Pre-treatment DKK1 correlated with FRP (p = 0.01, r2 = 0.39), but there was no correlation post-treatment. Post-treatment DKK1 correlated with both serum calcium (p = 0.04, r2 = 0.49) and BAP (p = 0.005, r2 = 0.65). There was no difference between breast and prostate cancer patients. Conclusions: It is feasible to measure DKK1 and FRP in patients with malignant bone disease. Treatment with ZA has measurable effects upon these and other serum markers. Further studies with more patients are needed to evaluate their potential as biomarkers. No significant financial relationships to disclose.
Mindfulness-Based Stress Reduction in Post-treatment Breast Cancer Patients: Immediate and Sustained Effects Across Multiple Symptom Clusters
