Immunotherapy for breast cancer: what does the future hold?
Checkpoint inhibitors make headlines with promising new data in cancer treatment on an almost daily basis, especially in melanoma and lung cancer. But what role are they - and other forms of immunotherapy - expected to play in breast cancer and why does progress appear to be slower than for some other tumours?
In this 5th edition of BIG Research in Focus scientific writer Jenny Bryan talks to leading researchers about current understanding of the immune response to breast cancer, ongoing trials of checkpoint inhibitors, and novel approaches to boost T lymphocyte and other immune cell activity.
Read the insights from Professors Sherene Loi (Peter McCallum Cancer Centre, Australia), Ton Schumacher and Marleen Kok (The Netherlands Cancer Institute, The Netherlands), Yosef Yarden (The Weizmann Institute of Science, Israel) and Laurence Zitvogel (Gustave Roussy Comprehensive Cancer Institute, France), introducted by an editorial of Prof. Fabrice André, (member of BIG Executive Board; Gustave Roussy Comprehensive Cancer Institute, France).
Here is a short extract from the article:
Associate Professor Sherene Loi, clinician-scientist at the Peter McCallum Cancer Centre, Melbourne, Australia, explains that, although breast cancer is not as immunogenic as melanoma and renal cell carcinoma, which have been the subject of immune based trials going back to vaccines and interferon, immunotherapy still holds great potential.
Anticancer immunotherapy has traditionally been classified as 'passive' or 'active', depending on whether or not it activates the immune system to attack tumour cells. Passive immunotherapy, such as tumour-targeting monoclonal antibodies and adoptive T-cell transfer, does not stimulate the immune system but works directly against tumours, while active forms of immunotherapy, such as checkpoint inhibitors and anticancer vaccines, interact with the immune system to stimulate tumour attack.
'The whole idea behind immunotherapy in the broadest sense is that the immune system does detect and fight cancer cells, but we need to find ways to enhance its effectiveness, particularly after it has deteriorated following chemotherapy and radiotherapy, says Professor Yosef Yarden, from the Weizmann Institute of Science, Rehovot, Israel. 'Until now, passive methods, such as monoclonal antibodies, have proved most successful but the newer active treatments such as checkpoint inhibitors are promising'.
Passive immunotherapy in the form of trastuzumab for HER2 positive (HER2) disease has been part of breast cancer therapy for nearly 20 years but the triple negative breast cancer (TNBC) is the main target for active immunotherapy with checkpoint inhibitors.
Dr Marleen Kok, medical oncologist at the Netherlands Cancer Institute (NKI), Amsterdam, The Netherlands, explains that the clinical need is highest in women with TNBC as tumours tend to be more aggressive and there are currently no targeted treatments. However, as there is a subset of women wiht oestrogen receptor positive (ER+) tumours who have a high mutational load similar to that in melanoma and triple negative disease, these patients may also benefit from checkpoint inhibitors.
'Our goal must be to target the right combination of immune treatments at the right subgroups of patients', she says.