This book aims at highlighting the present and very dynamic development in the field of upper GI cancers. Oesophageal and gastric cancer are diseases with poor prognosis. Looking back to history enormous efforts to treat these serious malignancies have been dated already to the ancient periods. The introductory chapter of this issue is therefore dedicated to history of gastric cancer that is tightly connected to history of development of surgical techniques. Surgery remains the basic cornerstone of the treatment of localized oesophageal and gastric cancer and chapters attributed to surgery delineate the sustained development either in classical surgical techniques but also an implementation of new technologies, especially robotic surgery into clinical practice. Supportive care and nutrition are an integral part of oesophageal and gastric cancer treatment. In this text we pointed specifically on the importance of perioperative supportive care. Diagnostic methods are crucial as endoscopy as a screening, diagnostic and therapeutic mean set a new era in gastric cancer treatment. Management of locally advanced cancer has been widely elaborated during the last two decades and implementation of new drugs and radiotherapy as well influenced clinical outcome and led to improvement in overall survival. However, despite of growing understanding of genomic and molecular landscape a number of targeted molecules failed in clinical practice. A special chapter is dedicated to pathology and vanishing targeted molecules in gastric cancer treatment. There is increasing insight into cancerogenesis as a complex process that also includesthe tumour-host interactions and therefore the chapter addressing the role of epidemiology, genomic and molecular background of cancer but also the role of microbiome was incorporated into this book. Recently, immune system is emerging as a fundamental element in understanding of cancer-host interactions biology. Immune checkpoint inhibitors that have already succeeded in more immunogenic tumours seem to be also a promising part of oesophagogastric cancer treatment and an overview of the latest achievements is presented in closing chapter of our publication.