Bone tenderness/bone pain
Description: Pain in any part of the skeletal system. Pain may be present with or without palpation.
Conditions Associated: Many different malignancies may cause bone pain. More common • Prostate cancer • Breast cancer • Multiple myeloma • Hodgkin’s and non-Hodgkin’s lymphoma • Lung cancer • Ovarian cancer
Mechanism/S: The mechanism is very complex. Key factors that contribute to the development of cancer-induced bone pain include: 1 complication of direct malignant invasion 2 malignancy-induced osteoclastosteoblast imbalance 3 alteration of the normal pain pathways. Complication of direct malignant invasion As tumour cells invade normal tissue and bone, they destroy normal architecture. In doing so they can cause nerve damage, vascular occlusion andor distension of the pain-sensitive periosteum – all of which will stimulate nerve afferents and produce pain.5–7 Alteration of osteoclasticosteoblastic balance Vascular occlusionnerve impingement Malignancy Direct invasion Cross-talk, malignant to osteoclasts Cytokine release e.g. TNF, IL-1 Endothelin 1 and PTH-rp release RANKRANK-L and OPG imbalance Alteration of pain pathways Cancer-induced bone pain in cancer-induced bone pain is still to be elicited. Alteration of normal pain pathways Studies have shown that metastatic malignancies in bone can cause alterations within the pain pathway.5,6,11 These changes lower the pain threshold and increase the likelihood for a pain impulse to be sent. Changes in the CNS and pain pathways in bone malignancy that have been demonstrated include: 1 reorganisation of the dorsal horn and sensitisation of pain afferents to substance P (which stimulates pain pathways)8,9 2 astrocyte hypertrophy6 and decreased glutamate reuptake transporters, causing increased glutamate and excitotoxicity8,9 3 an increase in certain glial proteins found in the spinal cord that serve to increase the transmission of pain8 4 the acidic environment produced by osteoclasts may stimulate pain receptors.5,9
Sign Value: New-onset bone pain is an important sign to recognise in both the cancer-naïve patient and those with a known diagnosis. Bone pain is the most frequent complication of metastatic bone disease,12,13 being reported in 50–90% of patients with skeletal metastases and in 70–95% of patients with multiple myeloma. Indeed, in patients with underlying metastases, bone pain or bony tenderness may be the first complaint described, especially in the case of multiple myeloma.
