Jet lag drug may aid cancer patients
Painful side effects from cancer medicines could be tackled with a drug that eases the effects of jetlag, research suggests.
The drug – known as melatonin – appeared to prevent pain caused by chemotherapy damage to nerves. It blocked harmful effects on nerve health, the study with rats shows.
Experts say the findings help scientists understand more about ways to limit painful side effects of chemotherapy.
Scientists from the Universities of Edinburgh and Aberdeen focused on a common condition known as chemotherapy-induced neuropathic pain (CINP), which causes tingling and pain sensation to touch and cold temperatures. These effects can be severe enough to cause patients to limit or even cease their chemotherapy treatment with consequent effects on quality of life and survival.
Prevention not cure
The study showed that melatonin given prior to chemotherapy limited the damaging effect on nerve cells and the development of pain symptoms.
In this study, melatonin did not alleviate pain when CINP had already developed, suggesting that its potential benefits could be as prevention rather than cure.
Importantly, melatonin treatment did not interfere with the beneficial anticancer effects of chemotherapy in human breast and ovarian cancer cells.
Findings also showed that melatonin reduced damage caused by chemotherapy to vital parts of nerve cells known as mitochondria. Experts say reducing harm to these cell energy centres could hold the key to preventing CINP.
CINP affects almost 70% of patients undergoing chemotherapy. Everyday activities, including fastening buttons or walking barefoot, can cause pain that can persist even after the cancer is cured, meaning that some patients are unable to return to work or able to carry out household tasks.
We hope that developing a successful treatment will not only improve quality of life, enabling patients to resume normal daily activities, but that it could also have a positive impact on their cancer treatment by enabling them to continue with their chemotherapy.
Melatonin is a naturally occurring hormone that controls sleeping patterns, although synthetic versions can be produced in the laboratory. Melatonin can be used to alleviate sleep disturbance but is not available in the UK without prescription.
Professor Helen Galley from the Institute of Medical Sciences at the University of Aberdeen, who co-led the study, said: “These results are promising, especially as melatonin treatment is known to be safe in other conditions. However, more work will need to be done before we know if melatonin will help prevent pain in cancer patients undergoing chemotherapy.”
We are actively exploring an early-phase clinical study to see if these exciting laboratory findings might translate to direct benefit for patients undergoing chemotherapy. This is an area of real unmet need, where new therapies are urgently required.
Dr Carole Torsney from the Centre for Integrative Physiology, who co-led the study, said: “These findings are very exciting and suggest that melatonin could prevent CINP by protecting nerve cell mitochondria. Our next steps will be to further test this theory by looking at the effect of melatonin in other pain conditions that also involve mitochondrial damage.”
Holds promise for patients
Dr Torsney told us that this study holds promise for patients because melatonin did not impact on the ability of the chemotherapy to destroy cancer cells in the lab. She is hopeful this means that melatonin should not impact on cancer treatment but stresses that more work is required to find out whether it is safe and effective in cancer patients undergoing chemotherapy.
We are also interested in exploring whether melatonin is beneficial in other pain conditions with similar pathogenic mechanisms.
The study was published in the Journal of Pineal Research and was funded by the Association of Anaesthetists of Great Britain and Ireland, British Journal of Anaesthesia, the Royal College of Anaesthetists and the Melville Trust for the Care and Cure of Cancer.