Cornelius A. Thiels, D.O., M.B.A., is a surgical oncologist and hepatobiliary and pancreas surgeon at Mayo Clinic Comprehensive Cancer Center in Rochester, Minnesota. Dr. Thiels treats cancers and conditions including pancreatic cancer, neuroendocrine tumors, gastric cancer, metastatic colorectal cancer, soft tissue sarcomas, appendiceal cancers, and gastrointestinal stromal tumor (GIST). He is an expert in minimally invasive surgery, liver and pancreas surgery (robotic and laparoscopic), including the Whipple procedure, as well as placement and management of Hepatic Artery Infusion Pump Chemotherapy for the management of unresectable liver tumors. He has special expertise in multimodality treatment of advanced or metastatic cancers, in which surgery is combined with radiation, chemotherapy or immunotherapy. Dr. Thiels is dedicated to improving outcomes for patients with rare and advanced cancers. Mayo Clinic is top-ranked in more specialties than any other hospital, according to U.S. News & World Report, and the Cancer Center continually ranks among the top hospitals in the U.S. for Cancer. Mayo Clinic Comprehensive Cancer Center is a National Cancer Institute (NCI)-designated comprehensive cancer center.