Australian researchers have identified a naturally occurring hormone that could help make chemotherapy much more effective for people with lung cancer, as well as prevent their kidneys from damage -- a serious side effect of the treatment.

Despite advances in immunotherapy for lung cancer, less than a third of patients see the benefits, and they often develop serious side effects including kidney damage. The team discovered that a protein called activin is a culprit in both chemotherapy resistance and chemotherapy-induced kidney damage. "In chemotherapy-resistant tumours in mice, activin gets switched on in response to the damage caused by chemotherapy," Neil Watkins, Professor at the Garvan Institute for Medical Research in Sydney.

"Cancer cells can then enlist activin to protect themselves. At the same time, when activin is switched on, it promotes kidney injury," he added. Hormone follistatin was found to block activin, and help in the treatment of inflammatory and fibrotic diseases. The study on mice models, published in Science Translational Medicine, showed that hormone follistatin in combination with platinum chemotherapy, caused lung tumours to shrink and more animals to survive longer. Remarkably, kidney damage was also prevented, the researchers said.

"Many of us have heard about the devastating side effects of chemotherapy in cancer patients. Our discovery has the potential to not only increase the effectiveness of platinum chemotherapy, but also give patients a better quality of life by preventing kidney damage," said Kieren Marini from Hudson Institute of Medical Research in Melbourne.

Watkins noted that the use of follistatin is likely to be a safe and effective approach to make chemotherapy more effective in lung cancer. "Because follistatin is a hormone already found in the human body, there is much less potential for toxicity than with other drugs used to reduce chemoresistance." The team now plans to study other tumours where platinum chemotherapy is commonly used, such as bladder and head and neck cancers.