New therapeutic approach for treatment-resistant Estrogen Receptor Positive (ER+) breast cancer

Project Description

Estrogen Receptor Positive (ER+) breast cancer is the most diagnosed breast cancer subtype accounting for around 70% of all breast cancers. While standard of care treatment, which involves hormone-blocking (endocrine) therapy, is beneficial for most people, around 30% of people can become resistant to treatment, which can lead to metastatic disease – the primary cause of breast cancer mortality.

Professor Nicole Verrills and her team at the University of Newcastle and Hunter Medical Research Institute (HMRI) have discovered that ER+ breast tumours that are resistant to hormone-blocking (endocrine) therapy have low activity levels of a specific protein called PP2A. A medication currently used to treat another disease is known to increase the activity of PP2A. Early studies from the team found that this medication prevented the growth of ER+ breast cancer cells grown in the laboratory.

With the use of preclinical models, this NBCF-funded study will test whether this repurposed medication can be used to help ER+ breast cancers become more responsive to endocrine therapy. This innovative study has the potential to identify new ways to treat ER+ treatment-resistant breast cancer, helping to improve survival for people affected by ER+ breast cancer.

Why is this work needed

ER+ breast cancer is the most commonly diagnosed subtype of breast cancer and while most people will benefit from hormone therapy, resistance to these drugs can occur in around 30% of people. This can lead to metastasis, the primary cause of breast cancer mortality. Hence, new ways to treat treatment-resistant ER+ breast cancers are urgently needed.

Expected outcomes

Successful outcomes of this study will be to test the effectiveness of a repurposed medication that increases PP2A levels to treat ER+ breast cancer that is resistant to hormone therapy. This will provide the evidence needed to proceed to a clinical trial of this medication in people with endocrine-resistant ER+ breast cancer, helping to improve the survival of people affected by ER+ breast cancer