Over-diagnosis and over-treatment has become common when dealing with breast cancer, but a breakthrough may mean that thousands of women may be saved from mastectomies and radiotherapy.
The discovery of a new molecule may be the key to a wait and watch approach.
Up to 5,000 women a year are diagnosed with the disease, but until now, reports The Telegraph, doctors have not been able to tell which ones will become worse and which don't need treatment.
The research was funded by the Breast Cancer Campaign, which says that a routine test could spare women the difficult decision on whether to have treatment.
The Guardian reported: "They) found that the molecule alpha v beta 6 could tell doctors which cases of ductal carcinoma in situ (DCIS), a condition in which non-invasive cancerous cells are contained within the milk ducts of the breast, are most likely to develop into early invasive breast cancer.
Study co-author Professor Louise Jones said: "You have a chance you can watch and monitor (where the molecule is not present).
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"We often pick this [DCIS] up in screening, which means that women are 50 or older and if it takes 30 years for that disease to progress, watching and waiting might be a sensible way to go. It's difficult for women to accept that they might need to have a mastectomy for something that you don't know is going to harm them."
It has been described as a "huge step forward", and comes at the right time when there is concern over how care is meted out.
For some women, conjectured The Guardian, going through the physical experience and awful side effects of breast cancer recovery when they don't possibly need to, "outweighs the number of lives saved". If that is indeed true, then this discovery could make all the difference.
In the study, researchers examined 583 breast tissue samples and showed that there was a link between levels of the molecule αvβ6 and whether breast tissue was normal, had DCIS or had progressed to invasive breast cancer.
There found almost none of the molecules in normal tissues, but they were found in half of the DCIS cases - and in almost all of the cases of invasive breast cancer.