Bone health and metastatic breast cancer

Metastatic breast cancer can have a significant impact on bone health. Specifically, breast cancer cells can spread to the bone and damage the bone cells. This can increase your risk of a bone fracture (or a broken bone) and osteoporosis, causing bone pain. Treatment of metastatic breast cancer in the bone (bone metastases) aims to relieve symptoms and prevent further damage to the bone(s) affected. 

Treatments

Two types of medications can be used to strengthen bones, reduce bone pain and the risk of fracture: 

• Bisphosphonates (Zometa, Bondronat, Bonefos) – given intravenously or as oral tablets 
• Biologic agents, denosumab (Xgeva) – given as a monthly injection under the skin. 

People with metastatic breast cancer may take bisphosphonates or biologic agents to: 

• reduce bone pain 
• prevent bone fractures 
• reduce the need for radiotherapy of the bone cancer 
• maintain calcium levels in the blood. 

Side effects 

Bisphosphonates and biologic agents can cause a range of side effects, including: 

• diarrhoea 
• flu-like symptoms 
• nausea 
• hypocalcaemia (low levels of calcium). 

There is also a very low risk of osteonecrosis of the jaw (ONJ), a condition where there is a loss of blood flow to the bone tissue causing the bone to die. It can affect the jaw or – more rarely – the ear. If you have persistent jaw pain, swelling redness or ulcers in the gums, ear pain or ear discharge, tell your specialist. 

Prevention is important. Tell your dentist if you are going to be taking bone-strengthening medication. It is important to have a thorough dental examination and any necessary dental work prior to starting intravenous bisphosphonate therapy. This approach, along with good oral hygiene, six-monthly dentist visits (for a check-up and teeth clean) and paying close attention to any decay, will go a long way towards preventing ONJ.  

If you are experiencing any of these side effects talk to your treating team for advice and management.