Expert Directory

Thorvadur R. Halfdanarson, MD

Professor of Oncology
Mayo Clinic College of Medicine and Science
Consultant in Medical Oncology
Mayo Clinic
Rochester, MN

Thorvardur R. Halfdanarson, MD, is a professor of oncology at Mayo Clinic College of Medicine and Science in Rochester, MN. He has also served as a consultant in medical oncology at Mayo Clinic in Rochester, MN, since 2015. Additionally, Dr Halfdanarson is the associate medical director of the Cancer Clinical Trials Office at Mayo Clinic in Rochester and the co-chair of the Pancreatic Neuroendocrine Tumor Board at Mayo Clinic.

Dr Halfdanarson earned his medical degree from the University of Iceland and completed an internal medicine residency at The University of Iowa, followed a fellowship in hematology and medical oncology at Mayo Clinic in Rochester. He was on faculty as a medical oncologist at The University of Iowa and the Iowa City VA Medical Center after completing his fellowship in 2007, where he remained until he transferred to Mayo Clinic in Arizona. He was at Mayo Clinic in Arizona for 3 years. 

He specializes in gastrointestinal oncology, with a focus on neuroendocrine tumors, and staffs the Carcinoma of Unknown Primary Clinic at Mayo. Finally, Dr Halfdanarson is a member of the National Comprehensive Cancer Network guidelines panel for neuroendocrine tumors, the vice president of the North American Neuroendocrine Tumor Society, and the co-chair of the Neuroendocrine Tumor Group at the Alliance for Clinical Trials in Oncology.