A trial looking at anastrozole with or without surgery for older women with breast cancer (ESTEeM)

Cancer type:

Breast cancer




Phase 3

This trial was comparing surgery and anastrozole (Arimidex) with anastrozole alone for breast cancer. It was recruiting women over 75 years old with breast cancer that was oestrogen receptor positive Open a glossary item. The trial was supported by Cancer Research UK.

Doctors usually treated older women who have ER positive breast cancer with surgery and hormone therapy or with hormone therapy alone. But there was little research in older women to show who would benefit from having surgery as well as hormone therapy. Surgery has side effects and it is important that older women don’t have operations they don’t need.

Anastrozole (Arimidex) Open a glossary item is a type of hormone therapy called an aromatase inhibitor. It is used as standard treatment for women with breast cancer who have been through the menopause.

In this trial, women had surgery and anastrozole or anastrozole alone. The aims of this study were to find out

  • Which treatment was better at controlling the cancer
  • More about the side effects and how this affected quality of life
  • If other factors, such as age or other illnesses, could help doctors to decide which treatments are best for different women

Summary of results

This trial was never finished so there are no results available. The researchers were unable to recruit enough patients.

Recruitment start:

Recruitment end:

How to join a clinical trial

Please note: In order to join a trial you will need to discuss it with your doctor, unless otherwise specified.

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Chief Investigator

Ms L. Wyld
Mr M. Reed

Supported by

Cancer Research UK
National Institute for Health Research Cancer Research Network (NCRN)
University of Leeds
University of Sheffield

Other information

This is Cancer Research UK trial number CRUK/06/010.

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Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 798

Please note - unless we state otherwise in the summary, you need to talk to your doctor about joining a trial.

Harriet wanted to try new treatments

Picture of Harriet

“I was keen to go on a clinical trial. I wanted to try new cancer treatments and hopefully help future generations.”

Last reviewed:

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