title: Cancer initiation and progression: an unsimplifiable complexity.
abstract: BACKGROUND
  Cancer remains one of the most complex diseases affecting humans and, despite the impressive advances that have been made in molecular and cell biology, how cancer cells progress through carcinogenesis and acquire their metastatic ability is still widely debated.
  
  
  CONCLUSIONS
  There is no doubt that human carcinogenesis is a dynamic process that depends on a large number of variables and is regulated at multiple spatial and temporal scales. Viewing cancer as a system that is dynamically complex in time and space will, however, probably reveal more about its underlying behavioural characteristics. It is encouraging that mathematicians, biologists and clinicians continue to contribute together towards a common quantitative understanding of cancer complexity. This way of thinking may further help to clarify concepts, interpret new and old experimental data, indicate alternative experiments and categorize the acquired knowledge on the basis of the similarities and/or shared behaviours of very different tumours.
authors.affiliation: Laboratories of Quantitative Medicine, Istituto Clinico Humanitas IRCCS, Via Manzoni 56, 20089 Rozzano, Milan, Italy. fabio.grizzi@humanitas.it
authors.forename: Fabio
authors.initials: F
authors.lastname: Grizzi
authors.forename: Antonio
authors.initials: A
authors.lastname: Di Ieva
authors.forename: Carlo
authors.initials: C
authors.lastname: Russo
authors.forename: Eldo E
authors.initials: EE
authors.lastname: Frezza
authors.forename: Everardo
authors.initials: E
authors.lastname: Cobos
authors.forename: Pier Carlo
authors.initials: PC
authors.lastname: Muzzio
authors.forename: Maurizio
authors.initials: M
authors.lastname: Chiriva-Internati
mesh_terms: D000465:Algorithms; D003043:Cocarcinogenesis; D018450:Disease Progression; D006801:Humans; D008954:Models, Biological; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000209:etiology* / Q000473:pathology