Confusion over the location of breast cancers may have led to avoidable deaths and the prescribing of inappropriate treatments, according to new research.
Scientists writing in the journal Cell: Stem Cell said that medical professionals may have been looking for the most deadly forms of the cancer in the wrong place.
Tumours arise in two types of glandular tissue in the breast, the outer “basal” cells and inner “luminal” cells. Scientists previously believed that aggressive cancers were confined to basal cells and milder cancers to their luminal counterparts.
But the report found that the vast majority of inherited breast tumours with defective BRCA1 genes - one of the most aggressive types - have basal-like characteristics, a discovery that could lead to new prevention strategies and targeted treatments.
Study leader Dr Matt Smalley, from the charity Breakthrough Breast Cancer, said: “This knowledge will greatly improve the chance of finding effective new targeted treatments for breast cancer patients in the future.”
The study was carried out at Breakthrough’s laboratories at the Institute of Cancer Research in London.