Fig. 1.

Schematic diagram showing the mechanism of cancer-induced bone pain. The cell body of the primary afferent neurons innervating the body is in the dorsal root ganglia and it transports sensory information from the periphery to the spinal cord and brain. Unmyelinated C fibers are involved in the detection of a variety of harmful stimuli. When bone tumors occur, or when bone destruction occurs, sensory neurons will behave as sprout and produce toxic irritants. Besides, DRG activation, microglia activation, acidic environment production, inflammatory factor expression, ion channel changes and many other factors participate in the generation and maintenance of cancer pain.