Saving lives by preventing treatment resistance in breast cancers

Background

Every year, over 3,000 Australian women will die from breast cancer. It’s estimated that around half of these deaths are from breast cancers that have become resistant to endocrine therapies. Endocrine therapies (also known as hormone therapies) are a conventional treatment strategy for breast cancers, and they help save many lives across Australia. However, resistance to endocrine therapies is common and affects around 40% of people who undergo treatment. When a person becomes resistant to therapy, their breast cancer can continue to grow and aggressively spread to other parts of the body. Once this spread occurs, it is almost always fatal.

The research

As part of this project, Dr Caldon investigated the underlying causes of this resistance. They uncovered new ways to predict whether a breast cancer will become resistant to treatment, and even prevent the resistance happening in the first place.

In a key discovery, Dr Caldon has found that a person’s DNA plays a role in treatment resistance. They have identified ways that the DNA will change when endocrine resistance occurs. As the DNA in a breast cancer cell becomes more unstable, treatment resistance increases. The researchers believe this DNA instability is caused by a protein called CDK. Using pre-clinical models the team tested different drugs that were able to block CDK activity and prevent the acquisition of endocrine resistance.