Bone-tumor interface

Experimental cancer model showing tibial intramedullary prostate carcinoma growth. The bone response to tumor cells can be as heterogeneous as the tumors themselves. Not all bone changes are directly related to the tumor. Apart from the tumor type, tumor location, and tumor size, mechanical use and patient nutrition can influence the bone response. As the tumors grow, the normal remodeling of bone is interrupted, leading to a net loss or net gain in bone density. Prostate cancer usually induces rapid production of bone (net gain) in the medullary cavity, as seen here. Can you spot the pre-existing lamellar bone (red outline)? Also noted, tumor cells are never (or almost never) in direct contact with the bone matrix (calcium-phosphate, collagen type I, etc.). Tumor cells are separated from the matrix by a one-cell thick layer, such as active osteoblasts (seen here), bone-lining cells, or endothelium of medullary capillaries.