Over 60 per cent of women who have a form of breast cancer in the milk ducts (DCIS*) are spared a mastectomy, according to latest research published today in the British Journal of Cancer.
Researchers for the Sloane Project** examined how the size of the DCIS – measured by both imaging and pathology – related to the surgeon’s decision of whether to conserve or remove the breast.
They found that, out of 2,500 women who had DCIS detected by breast screening, around 70 per cent of patients had conservation surgery to remove the disease and save the breast.
Of those who had conservation surgery, 71 per cent only needed one operation to remove the cancer, 19 per cent needed a further operation and 10 per cent went on to have a mastectomy.
In situ (non-invasive) breast cancer is confined to the ducts or lobules of the breast and has not spread to the surrounding tissues of the breast or other parts of the body. It is therefore curable if removed completely, but if left untreated may become invasive breast cancer.
This research is part of a large review of screen-detected DCIS and its treatment over the past five years through the Sloane Project, investigating the best treatment methods for DCIS.
Dr Jeremy Thomas, study author and consultant pathologist from the Western General Hospital, Edinburgh said: “This study shows that comparing the size of tumours as measured by imaging to the actual size of the tumour removed at surgery, gives a clear indication of where to focus improvements in practice. The results are very encouraging showing that 90 per cent of patients offered breast conservation for DCIS have a successful surgical outcome, usually from one operation, and avoid mastectomy.
“Deciding the best surgery option for patients with in situ breast cancer is difficult and requires very careful pre-operative assessment to define the extent of disease. A mastectomy would almost always cure the disease but where possible we want to conserve the breast and only remove the tumour. In the future we would hope to see that, with improvements in imaging and pre-operative assessment, more women could avoid having mastectomies.”
Professor Stephen Duffy, Cancer Research UK’s professor of screening at Queen Mary University of London, said: ”In the screening era, large numbers of breast cancers are diagnosed at the DCIS stage. We have a responsibility to see that these cancers are not overtreated. Therefore it is good to see that the vast majority do not get a mastectomy. There is clearly room for improvement in that we can further reduce the need for re-operation. This problem can and doubtless will be reduced by high-quality pre-operative imaging.”
Sara Hiom, director of health information at Cancer Research UK, said: “In the past treatment for DCIS was nearly always mastectomy so it’s really encouraging to see that now around 60 per cent of women with DCIS have only the affected area removed, along with a border of healthy tissue around it.
“It’s important that women go for breast screening when invited. The programme is very successful at detecting early stages of the disease which means treatment can be much more effective.”
Dr Jeremy Thomas et al Radiological and pathological size estimations of pure ductal carcinoma in situ of the breast, specimen handling and the influence on the success of breast conservation surgery: a review of 2564 cases from the Sloane Project British Journal of Cancer http://www.nature.com/bjc/journal/vaop/ncurrent/abs/6605513a.html
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*Ductal Carcinoma In Situ – In situ (or non-invasive) breast cancer is confined to the ducts or lobules of the breast and has not spread to the surrounding tissues of the breast or other parts of the body. It may, however, develop into invasive cancer if left untreated.
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**The Sloane Project aims to record the present situation in the UK regarding the management of in situ breast disease, and to provide a guide to the optimal radiological assessment, pathological handling and reporting (including the features of greatest prognostic and clinical importance), surgical treatment and adjuvant therapy.
The Sloane Project was established in memory of the late Professor John Sloane, Professor of Pathology, Liverpool University who had a special interest in this area. The Sloane Project is led by Mr Hugh Bishop, Consultant Breast Surgeon, Royal Bolton Hospital. He is supported by a steering group representing all the main medical specialties with considerable support for data handling and interpretation from the West Midlands Cancer Intelligence Unit under the leadership of Dr Gill Lawrence.
The Sloane Project has been running for six years with more than 7000 patients entered – the project is voluntary, however over 80% of UK Screening Units contribute cases to this important audit – estimated about 50% of all relevant cases are now entered into the audit.
The Sloane Project is now funded by the National Health Service Breast Screening Programme (NHSBSP).
• Between 1st April 2007 and 31st March 2008, 16,792 breast cancers were detected within the NHS Breast Screening Programme (NHSBSP), of whom 3,311 (20%) had in situ/non-invasive breast cancer.
• There has been a marked increase in the incidence of in situ breast cancer since the NHSBSP started in 1988. The reason being that the trademark characteristic of microcalcification present in the majority of in situ breast cancers can be easily visualised radiologically on a mammogram.
• The invasive potential of in situ breast cancer is uncertain and accordingly the optimal method of treatment for every case is ambiguous and unclear. A mastectomy would almost always be curative, however this approach would be extreme in cases where breast conserving surgery would suffice. Identifying the optimal method of treatment can therefore be difficult.