Dr. Portwine completed her medical school training at The University of Toronto. Shewent on to do her Pediatric Residency Training and subsequently her subspecialty training in Pediatric Hematology/Oncology at the Hospital for Sick Children (HSC) in Toronto. Dr. Portwine completed a PhD in Molecular Oncology focusing on the inherited cancer susceptibility gene, p53, in conjunction with the Clinician Investigator Program at the University of Toronto. She was on staff as an Assistant Professor in the Division of Hematology/Oncology at HSC while completing her PhD. In February of 2002, Dr. Portwine joined the Division of Hematology/Oncology in the Department of Pediatrics at McMaster University as a Clinical Assistant and then became a faculty member with the title of Assistant Professor within the Department. She was promoted to the rank of Associate Professor in July 2008.
Since beginning at McMaster, Dr. Portwine has become the local Principle Investigator for several clinical trial consortiums, including the Children's Oncology Group (COG), and is the Senior Medical Officer through C17, liaising with Health Canada for pediatric oncology clinical trial approvals in Canada and dealing with the regulatory requirements of clinical trials. Research in fertility and quality of life issues in the oncology population is ongoing. She sits on several committees and has been engaged in Provincial and National Guidelines development in the supportive care of pediatric oncology patients. Clinically, her focus is dealing primarily with patients with solid tumors and in children with a genetic cancer predisposition. She is currently Vice Chair on the Board of Directors for Camp Trillium which is a camp focused on children with cancer and their families.