Oxford study to explore insulin levels and breast cancer treatment
Research at Oxford hospitals investigates treatment resistance
A new study based at Oxford University Hospitals is set to investigate how insulin levels might affect the effectiveness of treatment in women with the most common type of breast cancer.
The Trans-EndoNET study focuses on oestrogen receptor-positive, HER2-negative breast cancer and aims to understand whether insulin resistance influences the response to aromatase inhibitors, medications that reduce oestrogen levels and lower the risk of recurrence.
Oxford University Hospitals is one of 32 hospitals participating in this project, with patient recruitment expected to begin soon. The research is funded by the UKRI Medical Research Council (MRC) and the National Institute for Health and Care Research (NIHR).
Breast cancer treatment and insulin's role
ER+HER2- breast cancer, especially common in post-menopausal women, relies on oestrogen to drive tumour growth. Aromatase inhibitors, such as letrozole, are standard treatments given for five to 10 years after surgery.
Emerging research suggests metabolic factors, including elevated insulin levels, may affect how well patients respond to hormone therapy. Increased insulin levels have been linked to poorer breast cancer survival rates and treatment resistance, while reducing insulin levels may improve outcomes.
Dr Simon Lord, Director of Oxford Cancer Trials at the Department of Oncology, said: “The Trans-EndoNET study will help us understand whether insulin levels play a role in determining how well patients respond to aromatase inhibitors.”
It is estimated that one in three adults over 50 experiences insulin resistance, raising questions about its interaction with cancer treatments.
Building on research through EndoNET
The Trans-EndoNET study is part of the Phase III EndoNET trial at Oxford University Hospitals, which focuses on the benefits of taking a portion of aromatase inhibitor courses before surgery to shrink tumours and potentially reduce surgery requirements.
The EndoNET trial has 250 participants from across the UK, and samples collected from this trial will be used in Trans-EndoNET to explore the connection between insulin resistance and treatment response.
By examining tumour samples and blood insulin levels, researchers aim to identify whether insulin resistance could be a clinical marker for resistance to hormone therapy.
Professor Ramsey Cutress, EndoNET lead investigator and Professor of Breast Surgery at the University of Southampton, said: “Integrating this work within the EndoNET trial gives us a unique opportunity to link biological changes in the tumour with real-world treatment outcomes.”
Researchers are hopeful that the findings of Trans-EndoNET will lead to future trials testing dietary or medication-based strategies to lower insulin levels and improve breast cancer treatment responses.
“Trans-EndoNET is an important study,” said Patricia Fairbrother, a patient contributor to EndoNET and trustee of Independent Cancer Patients' Voice. “Patient representatives will be advising and ensuring participant needs are met throughout the study.”