Gastrointestinal cancer is a type of cancer that is characterized by malignant growth of cells in the gastrointestinal tract. This cancer targets the accessory organs of digestion such as esophagus, stomach, biliary system, pancreas, small intestine, large intestine, rectum and anus. There are several factors such as obesity, tobacco and alcohol use that lead to gastrointestinal cancer. Vomiting, poor digestion and visible swelling in the abdomen are some important symptoms of this type of cancer. Its diagnosis involves the examination of the lining of the stomach with a flexible lens containing tube, called an endoscope. Other diagnostic methods include imaging techniques such as X-rays, computed tomography (CT) scans, and magnetic resonance imaging (MRI). The most effective way to treat gastrointestinal cancer is surgery along with radiation therapy and chemotherapy to relieve the symptoms. The objective of this book is to present advancements in the researches on gastrointestinal cancers. Different diagnostic approaches and treatment strategies for these type of cancers have been included herein. The book will serve as a valuable resource for medical professionals and students alike.