Synopsised by Drs. Cathy Richards and Ann Hopkins

Ever since the 2018 Nobel Prize for Medicine or Physiology was awarded to two pioneers of the emerging science of immunotherapy, the scientific literature has been buzzing with new advancements in this field. So what is cancer immunotherapy, and what is its relevance to breast cancer?

Gatti-Mays et al., (1) recently published a key review examining how a patient’s own immune system can be harnessed to fight breast cancer. Any kind of therapy which helps the immune system attack a growing tumour is called a cancer immunotherapy. This paper explains how breast tumours are often ‘immunosuppressive’, meaning that they create an environment in which a patient’s immune system is unable to detect and fight tumours. The good news is that a lot of new approaches are being tested to overcome this problem. One way is to isolate a patient’s own immune cells from the blood, activate them to recognise the tumour, and then put them back into the body to fight the tumour cells that they can now recognise. Another way is to treat patients with drugs that increase the levels of certain tumour-fighting chemicals (cytokines) naturally produced by the body. Yet another way, as introduced by the Nobel Prize award, is to treat patients with drugs called ‘checkpoint inhibitors’. These drugs combat the ability of some tumours to switch off the immune response at so-called checkpoints, thereby restoring the patient’s own immune response so it can attack a tumour.

Collectively, these approaches represent a big leap forward in helping patients launch their own immune attack against their own individual tumours. However, Gatti-Mays et al. highlight the importance of future work on how to stop tumours developing immunosuppressive environments to protect themselves. When we are better able to switch those immunosuppressive environments into environments where a tumour cannot hide from the patient’s immune system; this will make breast cancer patients more responsive to immunotherapies and help improve survival.

1. Gatti-Mays ME, Balko JM, Gameiro SR, Bear HD, Prabhakaran S, Fukui J, et al. If we build it they will come: targeting the immune response to breast cancer. NPJ Breast Cancer. 2019;5:37.