Scientists have found a way of testing whether a person’s breast cancer is likely to return.
The research could allow for huge changes in the treatment of cancers, and identify those who are at most at risk of their treatment failing.
Looking for immune cell “hotspots” around tumours is a reliable way of telling whether a person is more likely to have their breast cancer relapse, the research found.
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The study also concluded that women who have more of those immune cells clustered around tumours are more likely to have their breast cancer return within ten years after it has been treated.
As well as allowing doctors to find the people who are most at risk of having breast cancer return, the findings could help inform what treatment people receive in the future.
The researchers wrote that scientists could exploit the findings to help advance the way that people are treated, and stave off any such relapses.
People who are diagnosed with oestrogen-sensitive breast cancer – which accounts for around 80 per cent of breast cancers, the most common cancer in women – respond well to treatment. But some patients are at particular risk of dying when it returns, especially after about five years.
The new research helps identify people who belong to that sub-group, in a move towards avoiding those relapses. It also means that those who aren’t part of those groups may be able to avoid chemotherapy.
Scientists from the Institute of Cancer Research looked at tissue samples from 1,178 women with the most common form of oestrogen-sensitive breast cancer.
They found that those whose immune cells showed the clustering behaviour had a 25 per cent higher chance of having their breast cancer return within 10 years. The chance it would return in five years was also 23 per cent higher.
Lead scientist, Dr Yinyin Yuan, said: “We have developed a new, automated computer tool that makes an assessment of the risk of relapse based on how cells are organised spatially, and whether or not immune cells are clustered together in the tumour.”
“In the most common form of breast cancer, oestrogen receptor positive, the presence of hotspots of immune cells clustered together in the tumour was strongly linked to an increased risk of relapse after hormone treatment.
“Larger studies are needed before an immune hotspot test could come to the clinic, but in future such a test could pick out patients at the highest risk of their cancer returning. It might also be possible to predict which patients would respond to immunotherapy.”
The findings appear in the Journal of the National Cancer Institute.
Researchers said that the study could go on to change the way that people are treated in the future, as well as helping identify the ways that treatment work.
Professor Paul Workman, chief executive of The Institute of Cancer Research, said: “What this study tells us is that the immune system probably has a key role to play in how breast cancer responds to hormone treatment.
“Measuring the immune response to cancer could be important in the future to help identify patients who could benefit from immunotherapy.”
Katherine Woods, from the charity Breast Cancer Now, which co-funded the study, said: “That this exciting immune tool could be added to existing prognostic tests to more accurately identify women at high risk of their breast cancer coming back is very promising.
“Automatically analysing the distribution of immune cells in a tumour is a big achievement, and if this approach is validated it could help doctors guide chemotherapy treatment.”