IN VITRO 3D MODELING OF ER+ BREAST CANCER AND PRIMARY ADIPOSE DERIVED STEM CELL DEMONSTRATES ALTERATIONS IN ENDOCRINE THERAPY RESPONSE DUE TO PATIENT CHARACTERISTICS.

Approximately 40% of ER + breast cancer patients present de novo resistance to endocrine therapy (ET).Recent studies point out the tumor microenvironment (TME) as having a key role in endocrine resistance in which adipose-derived stem cells (ASCs) play an essential role in cancer homeostasis.ASCs have demonstrated the ability to repair, maintain, and enhance surrounding tissue via paracrine signaling 1 which has the potential to affect cancer drug efficacy.Moreover, studies have pointed out that patient characteristics such as age and BMI may play a role in cancer progression. 2Unfortunately, most studies on ASC-breast cancer crosstalk have relied on established two-dimensional (2D) culture systems or the use of conditioned media that cannot replicate the complexity of the three-dimensional (3D) environment.Thus, there is a need for a system able to elucidate the interactions between ER + cancer cells and ASCs in a 3D environment to identify how patient characteristics may drive endocrine resistance.