Potential new route for treating breast cancer
Researchers have identified a potential target that could lead to new treatments for triple negative breast cancer.
A study has found targeted antibody therapies could offer “long-awaited” advances for patients with aggressive ‘triple negative’ breast cancer, following the discovery of a new target protein helping to drive the disease’s growth.
Scientists working at the Breast Cancer Now Research Unit at King’s College London and supported by the National Institute for Health Research Guy’s and St Thomas’ Biomedical Research Centre (BRC) found that a significant proportion of highly aggressive triple negative tumours, including those that are resistant to chemotherapy, produce high levels of a protein called folate receptor alpha (FRα).
The researchers found that antibody immunotherapies targeting FRα significantly reduced growth of triple negative tumours in mice, priming the immune system to recognise to attack cancer cells.
Triple negative breast cancer – which makes up around 15% of all breast cancers – is so-named for its lack of three key receptors that can be targeted with treatments in other forms of the disease.
Treatment options for triple negative patients are therefore usually limited to surgery, as well as chemotherapy and radiotherapy, which can weaken patients’ immune systems.
In recent years, other cancers have seen significant breakthroughs in immunotherapy, which involves reprogramming the immune system to recognise and kill cancer cells. However, immunotherapies that can benefit breast cancer patients have not seen the same success.
With triple negative breast cancers often being more aggressive as well as harder-to-treat than other types of the disease, survival outcomes are often poor for the 7,500 women diagnosed each year in the UK.
The new study confirms that FRα – a protein often produced at high levels in ovarian, lung, breast and other types of cancer – plays a crucial role in supporting growth and survival of triple negative breast tumours.
The team proposed that FRα could be a suitable target for different antibody treatment approaches. When FRα-targeting antibodies were linked to cancer growth-inhibiting drugs, they successfully sought out FRα, directly delivering cancer growth-inhibiting drugs to triple negative breast cancer cells, which resulted in smaller, slower-growing tumours.
The team now hope to further develop these novel antibody approaches, with the aim of refining these new lines of attack, and advancing them into clinical trials for triple negative breast cancer patients.
Dr Sophia Karagiannis, Head of Cancer Antibody Discovery and Immunotherapy at King’s College London and lead-researcher, said:
Having identified antibodies against this novel target that are able to restrict the growth of triple negative breast cancer cells in the laboratory, we are now concentrating on bringing forth a new generation of more effective antibody therapy approaches. Our ultimate aim is to translate the most promising of these to clinical testing in patients.
Professor Andrew Tutt, Director of the Breast Cancer Now Unit at King’s College London, said:
Through our combined strengths in breast cancer biology, cancer immunology, antibody engineering, and translation of targeted therapies at the Breast Cancer Now Unit at King’s, we are able to venture beyond existing conventional treatments, identify new targets on cancer cells and develop new agents for therapy never before examined in breast cancer. But it’s important to remember that this research is at an early stage and further work is needed in the laboratory before we know if these could develop into treatments for patients.
The study is published in Clinical Cancer Research. The study was largely funded by Breast Cancer Now – with additional support from Cancer Research UK, the Medical Research Council, the Academy of Medical Sciences, the Cancer Research UK/National Institute for Health Research (NIHR) in England/Department of Health for Scotland, Wales and Northern Ireland Experimental Cancer Medicine Centre, the NIHR Biomedical Research Centre at Guy’s and St Thomas’ and King’s College London. Patient tissue samples were provided by King’s Heath Partners Cancer Biobank in London.
Read more on the BRC website.
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