A research breakthrough could mean that a significant proportion of the 4,800 women diagnosed with DCIS each year in the UK could avoid unnecessary procedures.

Tuesday 3 December 2013      Research
Significant breakthrough could tackle over-diagnosis and over-treatment of breast cancer

In exciting news today, Breast Cancer Campaign funded researchers at Queen Mary University of London’s Barts Cancer Institute have shown that a molecule called αvβ6 (alpha v beta 6) could tell doctors which cases of Ductal Carcinoma in Situ (DCIS), a condition where non-invasive cancerous cells are contained within the milk ducts of the breast, are most likely to develop into early ‘invasive’ breast cancer.

Around 4,800 cases of DCIS are diagnosed each year in the UK, with two thirds diagnosed through breast screening. If left untreated up to half of DCIS cases could progress into invasive breast cancer but it is not possible to say which ones so all women are offered treatment and left with the agonising decision of whether to have it or not.

With further research αvβ6 could be used to stratify patient treatment, so that a significant proportion of the 4,800 women diagnosed with DCIS each year in the UK could avoid unnecessary procedures. This would mean a reduction in the number of women requiring surgery and other treatments such as radiotherapy, addressing the issue of over-diagnosis and over-treatment of the condition.

Dr Michael Allen and Professor Louise Jones from  Queen Mary University of London’s Barts Cancer Institute looked at 583 breast tissue samples from normal breasts and those with DCIS, and showed that there was a link between levels of αvβ6 in myoepithelial cells (cells which form part of the milk duct walls) and whether breast tissue was normal, had DCIS or had progressed to invasive breast cancer.  There was almost no αvβ6 in cells from normal tissues, whereas over half of the DCIS cases had αvβ6 in the surrounding cells (52 per cent of non-high grade DCIS and 69 per cent of high grade DCIS) and nearly all DCIS cases that had already started to become invasive breast cancer had αvβ6*.

The researchers then looked at a further 104 cases of DCIS matched to long term follow up information on each woman and found that the levels of αvβ6 in patients’ myoepithelial cells were strongly associated with their DCIS recurring or progressing, and this effect was seen independently of the grade and size of the DCIS.

Women whose myoepithelial cells contained αvβ6 saw their disease recur around nine years earlier than those without αvβ6; cases with αvβ6 recurred in an average of 2.3 years compared to 11.4 years for those without αvβ6.

Professor Louise Jones, corresponding author on the study said:

“We are confident these results will be validated in further studies and from there we don’t envisage any barriers to this research resulting in the development of a routine test which could take place in the clinic. This will be a huge step forward in how we treat women with DCIS.

Our ultimate goal is that women diagnosed with DCIS without αvβ6 could be offered active monitoring, saving them from potentially unnecessary surgery and radiotherapy.

Further experiments using cell and mouse models showed that αvβ6 encouraged breast cancer cells to spread out and grow much faster. They also revealed that αvβ6 is dependent on two other proteins to promote cancer growth, TGFβ and MMP9, and with further research these could potentially be targeted with drugs to prevent DCIS from progressing.

The study’s lead author, Dr Michael Allen said:

“These findings show that we are really starting to find some clarity in the grey areas surrounding the subject of DCIS, and interestingly this insight has come from specialised cells which surround the DCIS, rather than the cancer cells themselves. There is still much more we need to do, but we have found some important correlations between the presence of the marker, αvβ6, and the progression of DCIS into invasive breast cancer, and that is very exciting.”

Baroness Delyth Morgan, Chief Executive of Breast Cancer Campaign said:

“This research could be key to the hunt to develop a life-changing reliable prognostic test for women with DCIS. Such a test would mean women with DCIS would finally be able to make informed decisions about their treatment. They would no longer face the agonising choice between risking their breast cancer becoming invasive or facing treatment without knowing whether their DCIS will become life-threatening or not.

A test won’t be available in the clinic overnight, but we’re hopeful that ongoing research will allow this to happen in the future, which will signal a pivotal moment in the diagnosis and treatment of breast cancer.”

“Breast Cancer Campaign encourages all women to be breast aware throughout their lives and attend their screening appointment when invited. The risk of breast cancer increases with age so women over 70 should request a screening appointment once they are no longer invited to attend.”

Linda, 59, from Oxford, was diagnosed with DCIS in November 2012. She had surgery, followed by radiotherapy. She is now waiting for her next mammogram in January 2014, which she will then have every year for five years. She said:

“Being diagnosed with DCIS was daunting, as it wasn’t something I had heard of before. Because of this, I wanted to make sure I knew everything and I am very grateful for the way my clinicians gave me clear and concise information when needed or when I asked for it. I think I am a positive person and there was no doubt in my mind about next steps - for me treatment was the only option. However, these were difficult choices, but I don’t think I am brave, I just take each day and each step as it comes. I am so lucky to have such a strong and supportive family who were with me every step of the way.”

* Grade is assessed on how different the cells look compared to normal breast cells.

Read more on this story on the Guardian website