John Marshall, MD, is a global leader in the research and development of drugs for colon cancer and other GI cancers. He is the principal investigator of over 150 clinical trials, at the local as well as national levels. Dr. Marshall is the clinical director of oncology for Georgetown University Hospital, associate director for clinical care of the Lombardi Comprehensive Cancer Center, and chief of the Division of Hematology-Oncology. He is widely published in the field of clinical oncology, reviews manuscripts for eight journals, and holds peer-reviewed grants from the National Institutes of Health.

In 2009, Dr. Marshall became the founding director of the Otto J. Ruesch Center for the Cure of Gastrointestinal Cancer. Combining expertise in molecular medicine, translational research, and a patient-centered philosophy, the Ruesch Center is dedicated to realizing the dream of individualized curative therapies through research, care and advocacy.

Dr. Marshall's own research focuses on the development of a novel vaccine for the treatment of advanced colon cancer. For over a decade, he has directed Lombardi's Developmental Therapeutics Program while also maintaining his regular clinical practice. Seeing about 60 patients each week, Dr. Marshall specializes in cancers of the GI tract at all stages of the disease.