Quest to beat cancer drugs’ deadly side-effect

The toxic side effects of some chemotherapy drugs which affect up to a quarter of patients by damaging their heart could soon be avoided thanks to research by University of Canberra scientist Dr Nicole Beard.

Dr Beard said that although anthracyclines are some of the most powerful and effective chemotherapy drugs to treat cancers such as breast cancer, sarcoma, lymphoma and children’s leukaemia, some can cause life-threatening side effects.

The associate professor in cardiac physiology explained this group of drugs has an unintended effect, proving to be toxic to the heart, a condition known as cardiotoxicity, causing arrhythmia, heart failure or sudden cardiac death.

Dr Beard said anthracyclines are used to treat 60% of childhood cancer patients. She explained that children are also more susceptible to cardiotoxicity than any other age group given that they live longer, having a higher chance of experiencing the drug treatment’s long-term effects.

“The statistics are really frightening. The risk of heart failure is 15-times higher in children treated with anthracyclines, than children who have not been treated for cancer,” she said, “and cardiotoxicity can happen at any time and it could be many years after receiving the chemotherapy treatment.”

Dr Beard said the problem has been that, despite decades of research, it’s been unclear how anthracycline cardiotoxicity is actually caused. However, she hopes this is about to change.

“My research has identified that anthracyclines can disrupt the pathway in the heart which controls the contraction and relaxation of the heart muscle, which gives us a heartbeat” she said.

“Our hope is that this knowledge will allow the design of co-therapies to be used with anthracyclines to prevent these complications or possibly aid in the design of less toxic anthracyclines.

There have been numerous international attempts to design an anthracycline analogue or an alternate method of drug delivery which has the effectiveness of anthracyclines in treating leukaemia and breast cancer, without the toxic side effects.

“We are already using lower doses of anthracyclines in chemotherapy than we have historically done, to try and avoid the cardiotoxic complications, but being able to treat or mitigate the side effects would open up more options for doctors.

“It would mean being able to use higher doses and/or longer treatment regimens, improving the remission rate for patients. It would also allow a broader population of cancer patients to be treated with anthracyclines, such as those with an underlying heart disorder,” Dr Beard said.

(Source: University of Canberra)