This is the third volume on gastrointestinal cancer of the Cancer Treatment and Research Series. The emphasis in this volume is to present a series of papers on areas of high clinical relevance in malignant diseases of the gut. As in the first and second volumes of this series, authors have been selected for their expertise and national and international prominence in their fields. This volume is organized so that papers explaining basic science pro spec tives proceed those dealing with clinical aspects of gastrointestinal cancer. It is clear that in many instances advances gastrointestinal carcinoma cannot be effectively treated if ' cure' is the desired goal. When faced with poorly treatable diseases it is obviously important to look toward the causes and prevention of these illnesses. For this reason, there are several chapters in this volume that examine the issue of carcinogenesis of gastrointestinal cancer. Likewise, in diseases that are poorly treatable in advances stages, one is interested in early detection. Thus, early screening of populations becomes important and is dealt with in three papers in this volume. Chapt ers on treatment explore innovative approaches to therapy of gastrointesti nal cancer. Second-look surgery with resection, arterial perfusion with che motherapy, adjuvant therapy and neoadjuvant therapy are all addressed in various chapters in this volume. Finally, four chapters deal with unusual problems in gastrointestinal cancer. These papers include discussions ofpri mary hepatobillary cancer, lymphoma of the gut, and gastrointestinal endo crine tumors.