Cancer-induced Bone Pain Impairs Burrowing Behaviour in Mouse and Rat

Cancer-induced bone pain remains a serious public health concern, with a need for translational behavioural tests in order to assess nociception in preclinical models of this condition. Burrowing is an innate, ethologically relevant rodent behaviour that has been proven sensitive to chronic pain conditions. Herein, we studied for the first time whether burrowing performance is altered in preclinical models of cancer-induced bone pain. Mice and rats were inoculated with syngeneic breast cancer cells. Bone degradation was radiographically evaluated and nociception was assessed in limb-use and burrowing tests. Cancer-bearing rodents showed reduced relative bone density and limb-use scores, confirming disease development. Burrowing performance decreased over time in both rodent models. Burrowing performance was reduced in both rodent models, indicating that the burrowing test is a relevant and reproducible behavioural test for assessing disease development in both mouse and rat models of cancer-induced bone pain.