A study looking at duct endoscopy before a mastectomy to treat or reduce the risk of breast cancer (INTEND III)

Cancer type:

Breast cancer





This study looked at putting a thin tube into the breast ducts to examine them and find out more about the breasts (duct endoscopy).

Some women have a mastectomy as part of their treatment for breast cancer. Occasionally, women who are at a very high risk of developing breast cancer because of an inherited gene fault may have a mastectomy to reduce their risk.

Doctors want to improve ways of diagnosing and treating breast cancer. In this study, they were trying to find out more about the breast ducts. There is a network of breast ducts leading from the breast lobes to the nipples. The lining of these ducts is the most common place for breast cancer to start.

The doctors used a very fine tube connected to an eye piece to look inside the breast ducts of women just before their mastectomy. Looking at the ducts in this way is called duct endoscopy.

The study doctors also took samples of fluid from the breast ducts. The breast cells always produce some fluid, even when a woman is not producing breast milk. As the fluid is in direct contact with the cells lining the breast ducts, the doctors thought they would get useful information by looking at it closely.

The aims of this trial were

  • To find out more about the structure of the breast ducts
  • To see if it was possible to diagnose or treat breast cancer through the opening from the nipples into the breast ducts

Summary of results

The study team found they could reach breast cancer through the opening of the nipple into the breast ducts. This means that in future, they may be able to diagnose or treat it through the ducts. They also learnt more about the structure of the breast ducts.

This study recruited 58 women who were to have a mastectomy. They had a breast endoscopy before their mastectomy, while they were under general anaesthetic. The researchers also took fluid samples from the ducts.

After the breast was removed, it was sent to the laboratory. In the laboratory the researchers examined the ducts to see how close they were to the cancer.

They also took a CT scan Open a glossary item of some of the removed breasts, to see if they could get a 3D image of the ducts.

Of the 58 mastectomies, 47 had at least 1 duct the researchers had taken a fluid sample from. When they examined the ducts in these 47 breast tissue specimens, they found that

  • 29 showed ducts that had cancer
  • 6 showed ducts that didn’t have cancer
  • In 12 they couldn’t get a result as the procedure hadn’t worked

They concluded that for the majority of people they could access breast cancer through the nipple opening and breast ducts. They also concluded that CT scans could be used to get a 3D image of the breast ducts.

We have based this summary on information from the team who ran the trial. The information they sent us has been reviewed by independent specialists (peer reviewed Open a glossary item) and published in a medical journal. The figures we quote above were provided by the trial team. We have not analysed the data ourselves.

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 Dominique Twelves
Mr Gerald Gui

Supported by

Breakthrough Breast Cancer
The Royal Marsden NHS Foundation Trust

If you have questions about the trial please contact our cancer information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle - 909

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

Last reviewed:

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