title: Exosomes: novel implications in diagnosis and treatment of gastrointestinal cancer.
abstract: BACKGROUND
  Amongst all cancer subtypes, gastrointestinal tumours are responsible for most cancer-related deaths. In most of the cases, the limitation of the prognosis of patients with malignant gastrointestinal tumours can be attributed to delayed diagnosis of the disease. In the last decade, secondary prevention strategies, in particular tumour screenings, have been identified to significantly improve the identification of patients with early-stage disease, leading to more effective therapeutic interventions. Therefore, new screening methods and further innovative treatment approaches may lead to an increase in progression-free and overall survival rates.
  
  
  OBJECTIVE
  Exosomes are small microvesicles with a size of 50-150 nm. They are formed in the endosomal system of many different cell types, where they are packed with nucleotides and proteins from the parental cell. After their release into the extracellular space, exosomes can deliver their cargo into recipient cells. By this mechanism, tumour cells can recruit and manipulate the adjacent and systemic microenvironment in order to support invasion and dissemination. Cancer-derived exosomes in the blood may provide detailed information about the tumour biology of each individual patient. Moreover, tumour-derived exosomes can be used as targetable factors and drug delivery agents in clinical practice.
  
  
  CONCLUSIONS
  In this review, we summarise new aspects about novel implications in the diagnosis and treatment of gastrointestinal cancer and show how circulating exosomes have come into the spotlight of research as a high potential source of 'liquid biopsies'.
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, University Hospital, Fakultät Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Rahbari
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, University Hospital, Fakultät Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
authors.forename: Nuh
authors.initials: N
authors.lastname: Rahbari
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, University Hospital, Fakultät Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Reissfelder
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, University Hospital, Fakultät Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
authors.forename: Juergen
authors.initials: J
authors.lastname: Weitz
authors.affiliation: Department of Visceral, Thoracic and Vascular Surgery, University Hospital, Fakultät Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany. christoph.kahlert@uniklinikum-dresden.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Kahlert
mesh_terms: D055354:Exosomes / Q000502:physiology*; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000628:therapy*; D006801:Humans; D009385:Neoplastic Processes
keywords: Drug delivery; Exosomes; Extracellular vesicles (EV); Gastrointestinal cancer; Noninvasive screening; Pancreatic cancer; Tumour microenvironment