A study looking at the genetics of ductal carcinoma in situ (ICICLE)

Please note - this trial is no longer recruiting patients. We hope to add results when they are available.

Cancer type:

Breast cancer





This is a study to find genes that may increase the risk of ductal carcinoma in situ (DCIS). If you have DCIS, some cells inside the tubes in your breast (the ducts) have started to turn into cancer cells. If it is not treated, DCIS may go on to develop into an invasive ductal breast cancer. This trial is supported by Cancer Research UK.

In this study, the researchers will look at the genes of a large number of women who have been diagnosed with DCIS. They will find out more about their family history to see if any of their relatives have also had DCIS or breast cancer.

The aims of the study are to

  • Identify genes that may cause DCIS or increase your risk
  • Try and identify which women with DCIS would be more likely to develop invasive breast cancer if DCIS was not treated

Please note you won’t get any direct benefit from taking part in this study, nor will it affect any treatment you have. The findings may help women with DCIS in the future.

Who can enter

You can enter this trial if you

  • Have been diagnosed with DCIS either recently or in the past (if you have or have had invasive breast cancer but it was in your other breast, you can still take part)
  • Are female
  • Were 60 or younger when you were diagnosed with DCIS

Trial design

The study will recruit at least 3,000 women who have been diagnosed with DCIS.

A doctor who has been involved in your care will send you a letter explaining the study. If you agree to take part, you return the reply slip to the research team. A member of the research team will then contact you to give you more information about the study. They will send you

  • A letter
  • A questionnaire to fill in
  • A consent form for you to sign
  • A blood sampling kit

The questionnaire will ask questions about your health and the health of your family. By signing the consent form, you agree that the research team can look at your medical records.

You will give a small sample of blood at the hospital or at your GP surgery. Whoever takes your blood will use the blood sampling kit provided by the researchers. They will then send the blood sample, along with the completed questionnaire and signed consent form, to the research team. They will give you a copy of the consent form to keep.

The researchers will look at the DNA from your blood to try and find genes that may increase the risk of developing DCIS. And they will try to identify women with DCIS who are more likely to develop invasive breast cancer. If you have had surgery to remove breast tissue, the researchers may also get a sample of the tissue that was removed. They will do further genetic tests on this tissue sample.

If any of your close relatives have also had DCIS, the researchers may ask you to contact them about the study. If a relative is interested in taking part, the researchers will give you an information pack for them. The pack contains a letter explaining the study and a reply slip to send to the research team. If your relative returns the reply slip, one of the researchers will contact them directly to recruit them to the trial.

You may also ask a friend, or a relative by marriage, who hasn’t had DCIS to take part in the study. This is because the research team need to have blood samples from a group of people to use as a comparison. This is known as a control group. The control group will be made up of women who are over the age of 35 and

  • Have not had breast cancer or DCIS themselves
  • Don’t have any close relatives who have had breast cancer or DCIS

Hospital visits

Taking part in this study does not involve any extra hospital visits, apart from having the blood test.

Side effects

You may have some discomfort or bruising in the area where the blood sample is taken. There are no other side effects associated with taking part in this study.

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

Dr Rebecca Roylance
Dr Elinor Sawyer

Supported by

Cancer Research UK
Experimental Cancer Medicine Centre (ECMC)
NIHR Clinical Research Network: Cancer

Other information

This is Cancer Research UK trial number CRUK/08/046.

Questions about cancer? Contact our information nurses

Freephone 0808 800 4040

Last review date

CRUK internal database number:

Oracle 1737

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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