CHANGES OF BONE METABOLIC MARKERS IN PATIENTS WITH BONE METASTASES - CLINICAL-SIGNIFICANCE IN ASSESSING BONE RESPONSE TO CHEMOTHERAPY

To determine the changes in bone metabolism in response to combined ch emotherapy in patients with bane metastases (BM),we examined osteocalc in (BGP), alkaline-phosphatase (ALP), hydroxyproline (HYP), pyridinoli ne (PYR), and/or deoxypyridinoline (D-PYR) in 25 cancer patients. In p atients without BM, serum BGP was normal and not affected by chemother apy. In patients with BM, however, BGP was often abnormally high or lo w, and some patients reacted to chemotherapy with a BGP increase at 4 weeks after initiation of therapy. Such an increase was observed in th e group of patients who responded favorably to therapy as judged by a decrease in bone pain and tumor-associated biochemical markers. Urine HYP, PYR, and D-PYR were high in patients with BM before therapy; D-PY R decreased transiently at 2 weeks and increased thereafter. We assume that increased bone-resorption markers along with increased bone form ation markers after therapy would indicate recovery of coupled bone me tabolism, as the deranged bone remodeling is improved by tumor-regress ion. This study suggests that BGP and D-PYR can be useful early marker s to predict favorable bone response to chemotherapy in patients with BM.