Does the timing and order of breast surgery and hormone treatment affect the quality of life and the amount of surgery required in post-menopausal women with breast cancer? The EndoNET study

Not Applicable

• Conditions: ewly diagnosed strongly ER-positive HER-2 negative breast cancer; Cancer; Malignant neoplasm of breast

• Registration Number: ISRCTN11896599
• Lead Sponsor: niversity of Oxford

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2022-05-04
• Last Update Posted: 13 June 2023
• Study Completion: 2027-02-28

Recruitment & Eligibility

• Status: Ongoing
• Sex: Female
• Target Recruitment: 1440

Inclusion Criteria

Current inclusion criteria as of 02/06/2023:
Main study:
1. Female
2. Clinically post-menopausal; including one of:
2.1. Amenorrhoea >12 months and an intact uterus
2.2. Bilateral oophorectomy
2.3. For those with a history of hysterectomy, or hormone replacement therapy (HRT) within 12 months, venous FSH levels classified as post-menopausal by the testing laboratory if any doubt
3. Unifocal, newly diagnosed breast cancer visible on USS
4. Strongly ER+; defined as Allred scores of 7 or 8 or equivalent*
5. HER2- by immunohistochemistry, or 2+ and not amplified by in situ hybridisation
6. T-stage 1, 2 or 3 (=15 mm)
7. Axillary N0-1 on diagnostic USS +/- negative fine-needle aspiration (FNA) or core biopsy
8. Suitable for surgery and radiotherapy
9. Chemotherapy unlikely to be indicated
10. Participant is able and willing to give informed consent for participation in the trial
11. In the Investigator's opinion, is able to comply with all trial requirements
* or equivalent may include a histochemical score (H-score) = 200.

QRI (information study)
Patients:
1. Patients approached for participation in the EndoNET study
2. Patient inclusions are the same as for the EndoNET study

Healthcare professionals (HCPs) and research personnel (RPs):
1. HCPs or RPs involved in management, operation or recruitment for the EndoNET study
2. Trial management group (TMG) members with a role in planning/coordinating recruitment

Previous inclusion criteria:
Main study:
1. Female
2. Clinically post-menopausal; including one of:
2.1. Amenorrhoea >12 months and an intact uterus
2.2. Bilateral oophorectomy
2.3. For those with a history of hysterectomy, or hormone replacement therapy (HRT) within 12 months, venous FSH levels classified as post-menopausal by the testing laboratory if any doubt
3. Unifocal, newly diagnosed breast cancer visible on USS
4. Strongly ER+; defined as Allred scores of 7 or 8 or equivalent
5. HER2- by immunohistochemistry, or 2+ and not amplified by in situ hybridisation
6. T-stage 2 or 3 (>2 cm)
7. Axillary N0-1 on diagnostic USS +/- negative fine-needle aspiration (FNA) or core biopsy
8. Suitable for surgery and radiotherapy
9. Chemotherapy unlikely to be indicated
10. Participant is able and willing to give informed consent for participation in the trial
11. In the Investigator's opinion, is able to comply with all trial requirements

QRI (information study)
Patients:
1. Patients approached for participation in the EndoNET study
2. Patient inclusions are the same as for the EndoNET study

Healthcare professionals (HCPs) and research personnel (RPs):
1. HCPs or RPs involved in management, operation or recruitment for the EndoNET study
2. Trial management group (TMG) members with a role in planning/coordinating recruitment

Exclusion Criteria

Main study:
The participant may not enter the trial if ANY of the following apply:
1. Bilateral breast cancer
2. ER- or HER2+
3. Stage IV disease (distant metastasis)
4. Previous neoadjuvant treatment for breast cancer
5. Previous invasive malignancy within 5 years other than basal cell carcinoma
6. Concurrent use (at the time of randomisation) of HRT or any other oestrogen-containing medication (including vaginal oestrogens)
7. Ovarian suppression/ablation for the purposes of trial entry not permitted

QRI (information study):
Patients:
1. Patient exclusions are the same as for the EndoNET study
2. Patient does not wish to have consultations recorded and/or participate in interview

HCPs and RPs:
1. HCPs or RPs who do not wish to have consultations recorded and/or participate in interview

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
The EndoNET Trial has co-primary outcome measures: <br>1. Global HRQoL is measured by FACT-B at baseline, 6 weeks or post-operative, 5, 7, 12, and 15 months<br>2. Rates of breast conservation surgery measured using surgical data stored in patient records at 15 months