Breast cancer is the most prevalent and deadly in woman. ER+ breast cancer represents around two-thirds of all cases and has a favourable prognosis due to good response to endocrine therapy. However, these tumours present 25% of disease relapse due to drug resistance and metastatic behaviour. Tumour progression and acquired drug resistance are modulated by the interactions between tumour cells and the surrounding microenvironment. Most models employed to address these mechanisms fail to reflect the complex tumour microenvironment and do not allow long-term monitoring of tumour progression. (...
