title: Tumor cells are dislodged into the pulmonary vein during lobectomy.
abstract: OBJECTIVE
  Intraoperative tumor shedding may facilitate tumor dissemination. In earlier studies, shed tumor cells were defined primarily by cytomorphological examination, and normal epithelial cells could not always be distinguished from tumor cells. We sought to accurately identify tumor cells using single-cell sequencing and determine whether these cells were mobilized into the circulation during pulmonary lobectomy.
  
  
  METHODS
  Forty-two blood samples collected from the tumor-draining pulmonary vein at the end of lobectomy procedures were analyzed. Arrays of nanowells were used to enumerate and retrieve single EpCAM(+) cells. Targeted sequencing of 10 to 15 cells and nested polymerase chain reaction of single cells detected somatic mutations in shed epithelial cells consistent with patient-matched tumor but not normal tissue.
  
  
  RESULTS
  The mean number of EpCAM(+) cells in video-assisted thoracoscopy (VATS) lobectomy (no wedge) specimens (n = 16) was 165 (median, 115; range, 0-509) but sampling cells from 3 patients indicated that only 0% to 38% of the EpCAM(+) cells were tumor cells. The mean number of EpCAM(+) cells in VATS lobectomy (wedge) specimens (n = 12) was 1128 (median, 197; range, 47-9406) and all of the EpCAM(+) cells were normal epithelial cells in 2 patients sampled. The mean number of EpCAM(+) cells in thoracotomy specimens (n = 14) was 238 (median, 22; range, 9-2920) and 0% to 50% of total EpCAM(+) cells were tumor cells based on 4 patients sampled.
  
  
  CONCLUSIONS
  Surgery mobilizes tumor cells into the pulmonary vein, along with many normal epithelial cells. EpCAM alone cannot differentiate between normal and tumor cells. On the other hand, single-cell genetic approaches with patient-matched normal and tumor tissues can accurately quantify the number of shed tumor cells.
authors.affiliation: Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Mass; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Mass.
authors.forename: Xiaosai
authors.initials: X
authors.lastname: Yao
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Lahey Hospital and Medical Center, Burlington, Mass.
authors.forename: Christina
authors.initials: C
authors.lastname: Williamson
authors.affiliation: Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Mass; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Mass; Broad Institute of MIT and Harvard, Cambridge, Mass.
authors.forename: Viktor A
authors.initials: VA
authors.lastname: Adalsteinsson
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Lahey Hospital and Medical Center, Burlington, Mass.
authors.forename: Richard S
authors.initials: RS
authors.lastname: D'Agostino
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Lahey Hospital and Medical Center, Burlington, Mass.
authors.forename: Torin
authors.initials: T
authors.lastname: Fitton
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Lahey Hospital and Medical Center, Burlington, Mass.
authors.forename: Gregory G
authors.initials: GG
authors.lastname: Smaroff
authors.affiliation: Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Mass.
authors.forename: Robert T
authors.initials: RT
authors.lastname: William
authors.affiliation: Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Mass; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Mass; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Mass.
authors.forename: K Dane
authors.initials: KD
authors.lastname: Wittrup
authors.affiliation: Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Mass; Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Mass; Broad Institute of MIT and Harvard, Cambridge, Mass. Electronic address: clove@mit.edu.
authors.forename: J Christopher
authors.initials: JC
authors.lastname: Love
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood / Q000235:genetics; D015815:Cell Adhesion Molecules / Q000097:blood; D004252:DNA Mutational Analysis; D000071858:Epithelial Cell Adhesion Molecule; D005260:Female; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D008297:Male; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009154:Mutation; D036103:Nanotechnology; D009360:Neoplastic Cells, Circulating / Q000378:metabolism / Q000473:pathology*; D011013:Pneumonectomy / Q000009:adverse effects*; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D011667:Pulmonary Veins / Q000473:pathology*; D020775:Thoracic Surgery, Video-Assisted / Q000009:adverse effects*; D013908:Thoracotomy / Q000009:adverse effects*; D016896:Treatment Outcome
chemical_list: D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule