Development of Translational Microscale Systems to Interrogate How Biophysical and Biochemical Cues Alter the Phenotype of Hormone Positive Breast Cancer

Cancer is a complicated disease and one in every three diagnoses are women with breast cancer. Recent research shows that the progression of cancer depends strongly on interactions with other non-cancerous cells and non-cellular components. Metastasis, the spread of cancer to other parts of the body, is a key step in cancer progression and makes treatment harder, leading to poor response to treatments culminating in death in ~90% of patients. This dissertation focused on creating a series of microdevices as novel pre-clinical models of breast cancer. Two different devices were fabricated to (1) study how exposing cancer cells to the biophysical force they experience in the bloodstream affects their behavior and (2) a microdevice created an array of tiny tumors to study how cancer cells interact with non-cancerous cells. Results showed that cancer cells have activated growth and survival cues when exposed in the blood vessels. Additionally, cancer cells were found to grow faster and be less responsive to therapeutic when they were grown as tiny tumors with other healthy cells found in the tumor. These findings provide new information on why metastasis is such a threat in cancer treatment and why breast cancer patients can be non-responsive to therapies, even after initially responding well.