Breast Screening

What is ductal carcinoma in situ (DCIS)?

Ductal carcinoma in situ (DCIS) is an early form of breast cancer. It may be described as a pre-cancerous, pre-invasive, non-invasive or intraductal cancer. This means the cancer cells are inside the milk ducts or 'in situ' (in place) and have not developed the ability to spread either within or outside the breast.

Most women with DCIS have no signs or symptoms so it is mostly found through breast screening after having a mammogram. This is why DCIS has been diagnosed more frequently since three-yearly breast screening was introduced on the UK National Health Service for women aged over 50. One in every thousand women who attend for breast screening is diagnosed with DCIS (NHS Breast Screening Programme 2015). The mammogram shows a cluster of small white dots. These white dots contain calcium and are known as micro-calcifications. They are generally too small to be felt. Most micro-calcifications turn out not to be DCIS (see 'Benign breast problems').

A few women with DCIS do have symptoms. They may have a lump, a discharge from the nipple or, rarely, a type of rash involving the nipple called Paget's disease.

If DCIS is left untreated, it may, over a period of years, begin to spread into (invade) the breast tissue surrounding the ducts. It is then known as invasive breast cancer. DCIS is the most common kind of non-invasive breast cancer; there are different grades of it' low, intermediate and high. This grading is based on what the cells look like under the microscope. Low-grade DCIS has the lowest risk of developing into invasive cancer and high-grade the greatest risk.

DCIS is not harmful in itself, but it is usually treated to prevent it developing into an invasive breast cancer. Not every woman with DCIS will go on to develop breast cancer if it is left untreated, but it is not possible to predict reliably which women with DCIS will go on to develop invasive breast cancer. Treatment, usually surgical removal of the affected area(s) of the breast, aims to prevent the development of invasive cancer. For most women this will mean removing only a small part of the breast (lumpectomy or wide local excision). However, about three out of ten women (30%)* diagnosed with DCIS in the UK have their whole breast removed (see mastectomy for DCIS) because more than one part of the breast is affected.

In the UK, non-invasive cancers such as DCIS accounts for one in five cancers (20%) detected by screening; that's around two thousand women a year (NHS Breast Screening Programme - Helping you decide leaflet July 2013). Health professionals haven't yet reached a consensus about the nature of this disease and its management, although research is underway to inform this. Because DCIS has an uncertain natural progression, most women we spoke with found it hard to understand. None of the women we interviewed who had had DCIS had heard of it before. Many were confused as to whether it was actually cancerous or not. Most wanted more information about DCIS and many felt unprepared for the diagnosis because they'd had no symptoms.

Had not heard of DCIS before she was told she had it.

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Had not heard of DCIS before she was told she had it.

Age at interview: 52
Sex: Female
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So we went off to the hospital which was some distance away and still no problems and there was the same radiographer that I saw at the mobile unit and she showed me what they were looking at and she just called it 'chalk'. That's all I knew.

And then I had to wait and see the consultant radiologist and he did an ultrasound and then said, mentioned pre-cancerous cells and said "we'll do a biopsy and we can do it now" and I just thought "Bloody hell they're looking for cancer" [laughs]. 

So I phoned up NHS direct, phoned up Breast Cancer Care, only knew it was called 'chalk', had no other information. Oh and they'd mentioned calcifications, so that was the only thing I could mention.

Because I'd been, heard about pre-cancerous cells my husband did ask him if it was something leading up to cancer or cancer and he said it was cancer. They took us to see the breast care sister and she gave us a piece of paper with 'DCIS' on. That was it. That was all we knew. And we had to make a decision [about when to have the mastectomy] based on that. 
 

Had not heard of DCIS before her own diagnosis.

Had not heard of DCIS before her own diagnosis.

Age at interview: 52
Sex: Female
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So by then I was worried and you know I'd rung my husband and he had quickly looked on the Internet because they'd mentioned the word micro-calcification and they'd said that that could mean benign, it could be fine. But he looked up a site, he looked up some sort of site describing it and he came home more worried than I was. I was slightly rattled but he had seen that micro-calcification often did indicate a presence of cancer cells. So it's a, I don't know whether the [screening] literature really did prepare me very well. Thinking back I don't think it did but I also don't think I had the eyes to see it at the time because I felt it just wouldn't apply to me. 

The day that we received the results I was told that I had DCIS and they explained very briefly what it was. 

Had not heard of DCIS before and got contradictory information about it being cancerous.

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Had not heard of DCIS before and got contradictory information about it being cancerous.

Age at interview: 48
Sex: Female
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It was ok. Th kept lying to me. I mean I didn't really understand what I had. They told me it was a ductal carcinoma in situ. It was pre-malignant, it wasn't cancer, it was nothing. It was treated like it was nothing and it only occurred to me much later "why did they take away half my breast for nothing".

I looked it up eventually on the internet. I got a computer, this was a long time ago so not everybody had a computer, but I got a computer, looked it up, looked up DCIS and I found 'malignant condition'. Oh yes, I forgot to tell you that I saw the Oncologist just after my wide excision. And he said "do you know what you've had" and I said "yes, I've had DCIS but it wasn't malignant" and he said to me "of course it was malignant, who on earth told you it wasn't malignant?" And I said "the Surgeon". He replied "no he didn't". Which didn't make me feel exactly great because I wasn't lying. So I had these mixed messages of "it's not malignant", "yes it is malignant". I actually learned it was malignant from the Oncologist and I think that was another reason why I really thought "I need extra information to find out what is it? What is DCIS? What have I had?"
 

See more about women's experiences of DCIS here.

*NHS Breast Screening Programme- Uncertainties in the management of screen-detected ductal carcinoma in situ July 2008.
 

Last reviewed March 2016.

Last updated March 2016.

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