Dr. Fields specializes in surgical oncology, the surgical treatment of cancer, including tumors of the upper gastrointestinal tract, pancreatic cancer, liver tumors, gastric cancer, stomach cancer, GI stromal tumors, GIST, small bowel tumors, neuroendocrine tumors and carcinoid tumors. He has advanced training in surgical treatment of skin cancer, melanoma, Merkel cell carcinoma, basal cell cancer, squamous cell cancer, sarcoma and retroperitoneal sarcoma. He also treats patients with benign hepatobiliary disease and pancreatic conditions. Dr. Fields also performs isolated limb infusion (ILI) and isolated limb perfusion (ILP) for advanced extremity melanoma and other skin/soft tissue malignancies.