Dr. DeMatteo is the Chairman of the Department of Surgery and a Surgical Oncologist who specializes in treating diseases of the liver, bile duct, gallbladder, pancreas, and abdominal sarcomas (GIST).

His clinical research has focused on liver, bile duct, gallbladder, and pancreas cancers. In addition, he has led several national trials testing the benefit of imatinib mesylate (Gleevec) following surgery for gastrointestinal stromal tumor (GIST), a tumor that usually begins in the stomach or intestine.

In the laboratory he and his colleagues study the immune environment of the liver and tumor immunology, working to develop immune therapies to help prevent tumors from returning after surgery.