A preliminary study of pamidronic acid downregulation of angiogenic factors IGF-1/PECAM-1 expression in circulating level in bone metastatic breast cancer patients

OBJECTIVE: To evaluate the expressions of circulating angiogenic factors affected by pamidronic acid (PA) intravenous infusion in bone metastatic breast cancer patients and the impact on their prognosis. METHODS: Peripheral blood of ten bone metastatic breast cancer patients was collected for serum insulin-like growth factor-1 (IGF-1) and platelet endothelial cell adhesion molecule-1 expression detection just before and 2 days after PA infusion. RESULTS: Both IGF-1 and platelet endothelial cell adhesion molecule-1 concentrations decreased after PA treatment for 48 hours (P<0.05). Modification was defined as >20% decrease recorded 2 days after PA administration. The decrease of IGF-1 was more significant in breast cancer patients who had received previous hormonotherapy. Moreover, the progression-free survival of first-line chemotherapy treatment of IGF-1 modified patients was longer than that of IGF-1 unmodified patients (P=0.009). CONCLUSION: PA treatment could suppress circulating serum IGF-1 and platelet endothelial cell adhesion molecule-1 concentrations; moreover, the prognosis of patients in IGF-1 unmodified group was relatively poor.