The potential of immunotherapy as a treatment for ER+ve breast cancer

Project Objective
Treatments that stimulate the immune system to attack tumours have revolutionised the treatment of some cancer types. However, these treatments have not yet been used effectively in breast cancer. More than three quarters of women with breast cancer present with the hormone-sensitive form of the disease and are subsequently treated with anti-oestrogen therapy. We have previously shown that treatment with anti-oestrogen drugs leads to infiltration of immune cells into breast tumours. We plan to investigate whether using either of two different immunotherapies in conjunction with anti-oestrogen therapies can stimulate an immune response directed against the tumour. This work will help assess whether these therapies are appropriate for treating oestrogen receptor positive tumours and, if so, whether they should be administered at the same time or separately.

They have demonstrated that treatment with anti-oestrogen therapy in combination with an anti-tumour vaccine and an immune checkpoint inhibitor leads to tumour regression in our oestrogen receptor breast cancer model. This combination of treatments appears to increase immune cell infiltration into the tumour and redirects the immune cells towards an anti-tumour response. This suggests that this combination of treatments may have efficacy in the treatment of oestrogen receptor breast cancer patients and that the ordering of these treatments maybe crucial to their success.

HOST INVESTIGATOR: University of Otago