Dr. Sun attended medical school at the University of Calgary and subsequently moved to Northern Ontario for his general surgical residency. He concurrently completed a Masters in Public Health from Harvard University, then finished a fellowship in thoracic surgery at the University of Ottawa. He has since moved back to Thunder Bay to establish a practice alongside Dr. Gehman at the Thunder Bay Regional Health Sciences Centre.

Dr. Sun currently offers services in Thoracic and General Surgery, including aspects of advanced endoscopy such as EBUS and EUS.