title: Blood-based analyses of cancer: circulating tumor cells and circulating tumor DNA.
abstract: The ability to study nonhematologic cancers through noninvasive sampling of blood is one of the most exciting and rapidly advancing fields in cancer diagnostics. This has been driven both by major technologic advances, including the isolation of intact cancer cells and the analysis of cancer cell-derived DNA from blood samples, and by the increasing application of molecularly driven therapeutics, which rely on such accurate and timely measurements of critical biomarkers. Moreover, the dramatic efficacy of these potent cancer therapies drives the selection for additional genetic changes as tumors acquire drug resistance, necessitating repeated sampling of cancer cells to adjust therapy in response to tumor evolution. Together, these advanced noninvasive diagnostic capabilities and their applications in guiding precision cancer therapies are poised to change the ways in which we select and monitor cancer treatments.
  
  
  CONCLUSIONS
  Recent advances in technologies to analyze circulating tumor cells and circulating tumor DNA are setting the stage for real-time, noninvasive monitoring of cancer and providing novel insights into cancer evolution, invasion, and metastasis.
authors.affiliation: Authors' Affiliations:Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, Massachusetts; Howard Hughes Medical Institute, Chevy Chase; and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MarylandAuthors' Affiliations:Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, Massachusetts; Howard Hughes Medical Institute, Chevy Chase; and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Haber
authors.affiliation: Authors' Affiliations:Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, Massachusetts; Howard Hughes Medical Institute, Chevy Chase; and Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland velculescu@jhmi.edu haber@helix.mgh.harvard.edu.
authors.forename: Victor E
authors.initials: VE
authors.lastname: Velculescu
mesh_terms: D000818:Animals; D004273:DNA, Neoplasm; D006801:Humans; D009369:Neoplasms / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy / Q000235:genetics; D009360:Neoplastic Cells, Circulating
chemical_list: D004273:DNA, Neoplasm