An Overview of the Bench to Bedside Models of Breast Cancer in the Era of Cancer Immunotherapy

One of the barriers to novel treatment developments within breast cancer is the ability to prove efficacy in the preclinical setting before moving on to clinical trials. Preclinical models range from single cell monolayers to more sophisticated humanised PDXs systems each with their set of advantages and limitations. Modelling the immune environment in cold tumours, such as breast cancer can also be challenging as are currently no clearly defined markers that can stratify patients based on treatment response. Immune checkpoints receptors such as PD-L1 may not show predictive outcomes in this tumour type. Furthermore, the heterogeneity of breast cancer may be difficult to recapitulate at the bench side. In this review, we provide an overview of the available in vitro, in vivo and ex vivo models of breast cancer with consideration of how these may extrapolated to the investigation of the role of the immune system and immunotherapy developments in breast cancer.