ABSTRACT
Prostaglandins may play a local role in cancer-related osteolysis but are rarely implicated in hypercalcemia of malignancy.
Cytokines Transforming growth factor is secreted by many cancer cells in an autocrine way. Because of partial amino acid homology, it may stimulate the epidermal growth factor (EGF) receptor, inducing enhanced bone resorption. Other growth factors – e.g. interleukins IL-1 and IL-6 and tumor necrosis factor (TNF) induce bone resorption in vitro, but their clinical significance has not been shown in vivo. These factors act in the proximity of tumor cells, transforming infiltrating macrophages into osteoclasts, and thus generating lytic lesions.
