Breast cancer surgery and chronic pain: Who is at risk?

An important study on why some women suffer long-term pain after breast cancer surgery is being undertaken by an Auckland anaesthetist.

Dr Daniel Chiang and his research team are following 220 patients from preparation to six months after, their breast cancer surgery. He has received an ANZCA Research Foundation grant of $150,000 over two years that allows researchers to investigate how genetics might play a part in who develops chronic pain.

A previous study by Dr Chiang’s team revealed more than half of patients undergoing breast cancer surgery described some pain at six months to three years after surgery with nearly a quarter reporting moderate to severe pain.

Dr Chiang says this latest study will look at a comprehensive range of the risk factors such as how patients process pain, demographics, and what medical and surgical treatment the breast cancer patients received.

“Added to that, we are looking at how patients’ genetic make-up will influence their pain. The range of this study means we can also look at how these genes are regulated, and if chronic pain after breast cancer surgery results from these genes being turned off through the treatment. This sort of complete study hasn’t been done before,” he says.

Dr Chiang says the research will help identify which patients may go on to develop chronic pain after breast cancer surgery. “This means we can look at ways of adapting medical treatment for these patients even before surgery takes place.”

Many treatments for chronic pain only work for 25 to 50 per cent of patients. Dr Chiang says if they can select therapy more effectively, they can avoid patients having to try out multiple drugs and being exposed to unwanted side effects.

A total of $1.91 million has been awarded by the ANZCA Research Foundation for 2018. The Foundation supports research projects across the fields of anaesthesia, perioperative and pain medicine.