This book provides an up-to-date overview of gastrointestinal malignancies, including prevention, early detection, intervention, and life-extending therapeutics. It also assesses various biomarkers used for diagnostics, prognostics and prediction of response to chemoresistance. Further, it discusses the latest trends in the use of small-molecule targeted therapies and immunotherapies as single agents or combination with other treatments. Since resistance to radiation and chemotherapy contribute to the high recurrence and poor survival rates, improving the outcome for GI malignancies is dependent on the introduction of new biomarkers and therapeutic agents. Lastly, the book systematically investigates novel theranostics approaches using nanotechnology for the detection, diagnosis, and personalized treatment of GI malignancies.