Dr. Siu is a senior medical oncologist at Princess Margaret Cancer Centre since 1998, and has been a Professor of Medicine at the University of Toronto since 2009. She is the Director of the Phase I Program and Co-Director of the Bras and Family Drug Development Program at Princess Margaret Cancer Centre, and holds the BMO Chair in Precision Genomics. She is also the Clinical Lead for the Tumor Immunotherapy Program at Princess Margaret Cancer Centre. Dr. Siu previously served on the Board of Directors for the American Society of Clinical Oncology (ASCO), Nomination Committee for the American Association for Cancer Research (AACR), and the Board of Directors for the AACR. She is the President Elect of AACR in 2024-2025.

Dr. Siu’s major research focus is in the area of new anticancer drug development, particularly with respect to phase I trials and head and neck malignancies. She is the Principal Investigator of a phase I cooperative agreement UM1 award sponsored by the United States National Cancer Institute. In addition to her active research in early phase clinical trials, she has been leading genomics initiatives and immuno-oncology trials at the Princess Margaret Cancer Centre. Together, the three programs of drug development, cancer genomics and tumor immunotherapy form a triad of synergy that supports the institution’s core vision to deliver precision cancer medicine.

Internationally, Dr. Siu was the recipient of the US National Cancer Institute’s Michaele C. Christian Award in 2010, European Society of Medical Oncology’s Targeted Anticancer Therapies (TAT) Honorary Award in 2020, Canadian Cancer Trials Group’s Maria Ricci Memorial Lectureship in 2023, and ASCO’s highest honor - David A. Karnofsky Memorial Award in 2024. Dr. Siu received the 2024 Life Time Achievement Award from the Chinese American Hematologist and Oncologist Network (CAHON). For her mentorship of early career investigators, Dr. Siu received the International Women Who Conquer Cancer Mentorship Award from ASCO in 2020. Dr. Siu has published nearly 400 peer-reviewed manuscripts, and she is the co-Editor-in-Chief for AACR’s Cancer Research Communications, and is on the editorial board for Cell and Cancer Cell.