This issue of Surgical Oncology Clinics of North America, guest edited by Dr. Elin R. Sigurdson, is devoted to Clinical Trials in Surgical Oncology. Dr. Sigurdson has assembled expert authors to review the following topics: Commentary on Randomized Controlled Trials; Randomized Clinical Trials in Soft Tissue Sarcoma; Randomized Clinical Trials in Gastrointestinal Stromal Tumors; Randomized Clinical Trials in Melanoma; Randomized Clinical Trials in Breast Cancer; Randomized Clinical Trials in Gastroesophageal Carcinoma; Randomized Clinical Trials in Hepatocellular Carcinoma; An Update on Randomized Clinical Trials in Advanced and Metastatic Colorectal Carcinoma; Randomized Clinical Trials in Colon and Rectal Cancer; Randomized Clinical Trials in Anal Cancers; The Elderly in Randomized Clinical Trials; Hereditary Syndromes in Clinical Trials; Future Clinical Trials: Genetically Driven Trials; Randomized Clinical Trials in Neuroendocrine Tumors, and more!