1. Inova Schar Cancer Institute, Inova Health System , Fairfax, VA 22031 , USA
2. Stanford–Surgery Policy Improvement Research and Education Center (S-SPIRE), Department of Surgery, Stanford University School of Medicine , Palo Alto, CA 94305 , USA
3. Department of Surgery, Stanford University School of Medicine , Palo Alto, CA 94305 , USA
4. Division of General Surgery, Palo Alto Veterans Affairs Health Care System , Palo Alto, CA 94305 , USA