After his medical school at Dalhousie Medical School in 1994, Dr. Leong continued his General Surgery residency in Halifax during which time he also completed his master degree in Molecular Pathology. In year 2000, he moved to Toronto for his breast/melanoma surgical oncology fellowship. He became a Staff Surgical Oncologist at Princess Margaret Hospital and Mount Sinai Hospital 2 years later. He is currently an assistant professor at the University of Toronto. His research laboratory is within the Ontario Cancer Institude and his primary research interests include genetic epidemiology of breast cancer and novel techniques and technologies in the diagnosis of breast cancer and melanoma.