Dr. Popi Siziopikou, distinguished breast pathologist, named pathologist-in-chief at the Ginny L. Clements Breast Cancer Research Institute
Newly recruited researcher also appointed as professor and vice chair of pathology for research for University of Arizona College of Medicine – Tucson
The University of Arizona Comprehensive Cancer Center has named Popi Siziopikou, MD, PhD, pathologist-in-chief at the Ginny L. Clements Breast Cancer Research Institute. Dr. Siziopikou has also been appointed professor and vice chair of research in the College of Medicine – Tucson’s Department of Pathology and Laboratory Medicine. She will join the U of A on January 1.
An internationally recognized breast pathologist, Dr. Siziopikou joins the University of Arizona after 16 years at Northwestern University’s Feinberg School of Medicine and the Robert H. Lurie Comprehensive Cancer Center in Chicago. From 2009 to 2025, she served there as professor of pathology and medicine (hematology & oncology) and director of breast pathology. During her tenure, she established Chicago’s first subspecialty breast pathology section to support Northwestern’s multidisciplinary breast cancer program and founded the institution’s breast pathology fellowship, serving as fellowship director from 2010 to 2022.
“Dr. Siziopikou is a visionary leader in breast pathology whose work has shaped clinical practice, research and education across the field,” said Lisa Rimsza, MD, chair of the Department of Pathology and Laboratory Medicine. “Her commitment to advancing diagnostic precision and improving outcomes for patients with breast cancer will be a tremendous asset to our college and cancer center.”
Dr. Siziopikou’s clinical and research expertise focuses on breast pathology, breast tumor markers and molecular diagnostics in breast cancer. Her research interests include molecular markers with prognostic and predictive significance; mechanisms driving the development of triple-negative and HER2-positive breast cancers; progression from preinvasive to invasive disease; pregnancy-associated breast cancer; immuno-oncology biomarkers; and emerging applications of artificial intelligence in breast pathology.
“I’m honored to have Dr. Siziopikou join the University of Arizona Comprehensive Cancer Center,” said Dan Theodorescu, MD, PhD, the Nancy C. and Craig M. Berge endowed chair for the director of the Cancer Center. “Making innovative use of AI at the Ginny L. Clements Breast Cancer Research Institute is crucial to our convergent approach to research, and Dr. Siziopikou is uniquely qualified to lead this effort.”
Dr. Siziopikou holds numerous national and international leadership roles. She serves in a number of roles at the United States and Canadian Academy of Pathology (USCAP), the College of American Pathologists (CAP and the International Society of Breast Pathology (ISBP) as well as on the Lynn Sage Breast Cancer Symposium scientific planning committee. She is an editorial board member for Breast Cancer Research and Treatment and section editor for breast pathology for the Archives of Pathology & Laboratory Medicine.
Dr. Siziopikou is a contributing expert for the sixth edition of the WHO Classification of Breast Tumors and has held appointments with the American Association for Cancer Research (AACR), including service on its Pathology in Cancer Research Task Force and the Breast Cancer Research Grants Scientific Review Committee. She also served on the Program Committee of the San Antonio Breast Cancer Symposium (SABCS) for multiple years and she is a scientific committee member for the European Society for Medical Oncology (EMSO) 2024 and 2025 Congress.
Dr. Siziopikou earned her medical degree at Aristotle’s University School of Medicine in Thessaloniki, Greece, and a doctorate in immunology at Rush University in Chicago, Illinois prior to completing residency and fellowship training in pathology at Beth Israel Hospital/Harvard Medical School, in Boston, Massachusetts.