The EndoNET Trial

Neo-adjuvant endocrine treatment (NET) for post-menopausal women with breast cancer

Specialty: Breast cancer, breast surgery

Status: Open to Recruitment

About EndoNET

Welcome to EndoNET, a clinical trial designed to understand if a period of treatment with hormone therapy prior to surgery reduces the requirement for mastectomy and improves quality of life in post-menopausal women.

EndoNET was identified as a research priority by NICE for post-menopausal women with early breast cancer and the trial is driven by our patient advocates including Independent Cancer Patients’ Voice.

Trial details

EndoNET is a Phase III, multi-centre trial that evaluates whether endocrine treatment that prevents the production of oestrogens, when taken for 6 months prior to surgery, will shrink the tumour allowing for a reduction in the extent of surgery.

To be considered for the study, patients must be:

Post-menopausal
Strongly ER+
HER2-
Tumour ≥ 15 mm.

Participants will either be randomised to surgery at 2-4 weeks (up to 8 weeks permitted) or 6 months (+/- 1 month). Participants will complete quality of life questionnaires at intervals during their 15-month participation and rates of breast conservation surgery will be documented.

ENDONET RANDOMISATION

Eligible patients will either be randomised to either surgery at 2-4 weeks (up to 8 weeks permitted) or 6 months (+/- 1 month). Participants will start their endocrine treatment (aromatase inhibitors: letrozole, anastrozole or exemestane) after being randomised:

Endocrine treatment arm 1 and 2

The endocrine treatment offered in both arms is the same but the timing of surgery differs. This is to see if a longer duration of endocrine treatment before surgery will shrink the tumour to allow for less extensive surgery.

Trial Schema

EndoNET Trial Schema

Prospective Sites

If you are a UK hospital who would be interested in joining the 30+ centres taking part in EndoNET, please contact: endonet@nds.ox.ac.uk to find out more information and request a feasibility form. We are part of the NIHR Associate PI scheme and are on the NIHR Portfolio.