Bone cancer refers to cancer that has metastasized to the bones from another primary site. The bones serve as the body’s supportive framework, with many being hollow. Their outer layer comprises a network of fibrous tissues known as matrix, onto which calcium salts are deposited.
Under a microscope, tumor cells from bone cancer reveal their origin, resembling cells from their primary site despite relocating. For example, if lung cancer spreads to the bone, the bone tumor cells resemble and behave like lung cancer cells, necessitating treatment with drugs typically prescribed for lung cancer.
Aside from metastatic bone cancer, other types include those originating from blood-forming cells in the bone marrow but not within the bone itself. Multiple myeloma is a common example, while leukemia, though involving the bone marrow, is classified as a blood cancer rather than a bone cancer.
Bone cancers are generally categorized into primary and secondary types. Primary bone cancers, also known as true bone cancers or sarcomas, originate within the bone itself. Sarcomas can arise in bone, muscle, blood vessels, fibrous tissues, fat tissues, and other tissues, and may develop elsewhere in the body as well.