REMOVING large margins of surrounding healthy tissue when operating on a breast tumour is not of benefit, according to new analysis carried out by Dublin-based researchers.
Recent decades have seen a move towards “breast-conserving” surgery to remove lumps rather than the entire breast where possible, said Mr Malcolm Kell, a consultant surgeon with the Mater Misericordiae Hospital in Dublin and BreastCheck, the Government-funded screening programme for breast cancer.
However, Mr Kell was struck by the differences in practice in North America, which favours taking small margins of healthy tissue around the tumour, and in Europe where the margins taken are often larger.
“We want to make sure that the patients get the best chance of having no recurrence of the tumour or systemic disease. It’s easy to overtreat patients and you might think it’s of benefit to do excessively large surgery,” he said. “So it raises the question of how much should you remove around the tumour.”
Mr Kell and Mater colleagues Clive Dunne and John Burke, along with surgeon Monica Morrow from the Memorial Sloan-Kettering Cancer Centre in New York, analysed published clinical trial results for 4,660 patients treated with surgery and radiotherapy for ductal carcinoma in situ. Their meta-analysis found that taking a margin of more than 2mm of surrounding healthy tissue did not offer extra protection against the cancer recurring.
“It [2mm] is as effective as a wider margin, and if you just have that minimal removal you are getting the benefit of the best cancer outcome, but equally you are avoiding the detrimental effect of a bad aesthetic result for the patient,” said Mr Kell. “The standard of care for patients is breast-conserving surgery and to avoid a mastectomy wherever possible, and these findings are reassuring that this is a good thing to do.”
He said the findings also supported the ethos of cancer management in the BreastCheck programme, which invites women aged 50-64 to undergo routine mammograms. “If patients have had a very early cancer detected by going to BreastCheck, their long-term outlook is excellent.
“If you have removed the cancer but you have left them stigmatised because there’s a big area of the breast missing, then that’s a bad result.”
The results of the meta-analysis, which are published online this month in the Journal of Clinical Oncology, should help inform doctors and patients alike, according to Mr Kell. "It should reassure doctors and patients that narrow margins are safe in the long run. And hopefully it will benefit patients. It reassures them that they don't have to have excessively large amounts of tissue removed. This type of research evidence and information is the only way to move forward."
