Mariana Chavez Mac Gregor, MD, MSc, is a breast medical oncologist with strong interest in outcomes research. She obtained her medical degree from Facultad de Medicina at Universidad Nacional Autónoma de Mexico, and a Master of Science in Clinical Epidemiology at the Netherlands Institute of Health and Sciences. She completed her Clinical Residency in Internal Medicine at Barnes-Jewish Hospital/Washington University School of Medicine and a Clinical Fellowship in Medical Oncology at The University of Texas MD Anderson Cancer.

She is a Professor in the Department of Health Services Research and a Professor in the Department of Breast Medical Oncology at The University of Texas MD Anderson Cancer Center. She has served in leadership roles within SWOG and ASCO. In addition of being committed to the care of breast cancer patients, she is a teacher and an educator. Her research program focuses in breast cancer outcomes with emphasis on disparities, cancer care delivery, guideline adherence and understanding the long-term effects of therapy in breast cancer survivors. She has published over 150 peer-review articles. She receives funding from BCRF and is a Susan G. Komen Research Scholar