Breast cancer breakthrough drug targets stem cells SCIENTISTS have targeted breast cancer stem cells for first time with an approach that could increase survival rates for women with aggressive cancers. In what campaigners described as a "significant breakthrough" in the field of breast cancer research, the team used a combination of drugs to target the cells that drive the disease to grow and spread. It is hoped that the findings could be used to help women with advanced cancers where current treatments fail. Each year in Scotland, almost 4,500 cases of breast cancer are diagnosed and more than 1,000 deaths caused by the disease. The latest study, published in the Clinical Cancer Research journal, has shown for the first time that breast cancer stem cells taken directly from patients can be successfully targeted to treat the disease. A stem cell is an early type of cell that goes on to divide and produce other types of cell, such as nerve and tissue. Breast cancer stem cells are a key target because if they are not destroyed they continue to divide and grow new tumours. But killing these "root" cells means the tumour cannot regrow. Dr Rob Clarke and Dr Gillian Farnie, from Manchester University, took 19 breast cancer samples from 16 women with advanced disease. They then isolated the breast cancer stem cells from these samples and treated the cells with lapatinib - a targeted therapy for breast cancers known as HER-2 positive - and another drug still in development. The new drug targets a molecule called InterLeukin-8 (IL-8), which is found in high levels in breast cancers with a poor prognosis. In the samples from HER-2 positive breast cancers, lapatinib became much more effective at stopping breast cancer stem cells from growing when it was combined with the IL-8 drug. The researchers said this was the first evidence that breast cancer stem cells taken directly from patients could be successfully targeted to treat the disease. Although the research focussed on HER-2 positive cancers, Dr Clarke said it demonstrated that targeting the IL-8 molecule had the potential to stop all types of breast cancer recurring and spreading, as well as other cancers. Dr Clarke said: "This research is in its early stages, but is hugely exciting, showing real promise for women with breast cancer. As targeted drugs similar to those used in this study have already been tested in patients, the time it takes to bring these findings into clinical trials will be significantly reduced. Breast cancer stem cells hold the key to vital new approaches and treatments to help us beat breast cancer once and for all. Baroness Delyth Morgan, chief executive of the Breast Cancer Campaign, which funded the work, said: "This research is a real game changer in the fight against breast cancer. At Breast Cancer Campaign we fund only the very best research and this is one of those stand-out projects, bringing real patient benefit from the best and brightest minds working to tackle breast cancer. We're hoping to see this work changing the treatment landscape in the next decade.