In mice, tumors of various origins have been found to stimulate cambium layer cells of
periosteum/perichondrium of adjacent orthotopic bone or cartilage to proliferate and/or
differentiate into osteoblasts or chondroblasts. Tumors may induce new bone and/or
cartilage formation. In progressively growing tumors the osteogenic/chondrogenic activity is
gradually surpassed by the resorptive processes mediated either by osteoclasts, directly by
tumor cells, or by tumor stroma. In regressing tumors, however, the deposits of new bone …