As a result of improved diagnostics such as new biomarkers, molecular imaging as well as new therapies based on randomized trials, neuroendocrine tumors are increasingly attracting the attention of physicians and scientists. In future, personalized medicine or ‘theragnostics’ and large-scale sequencing will rapidly change the understanding of cancer biology and will help to identify new targets as well as explain the causes of drug resistance. This book covers the most recent information on neuroendocrine tumors in terms of classification, molecular profiles and diagnosis and different types of treatment for neuroendocrine tumors.