title: KRAS mutations in pancreatic circulating tumor cells: a pilot study.
abstract: Pancreatic ductal adenocarcinoma (PDAC) is most often diagnosed in a metastatic stage. Circulating tumor cells (CTC) in the blood are hypothesized as the means of systemic dissemination. We aimed to isolate and characterize CTC to evaluate their significance as prognostic markers in PDAC. Blood obtained from healthy donors and patients with PDAC before therapy was filtered with ScreenCell® filtration devices for size-based CTC isolation. Captured cells were analyzed by immunofluorescence for an epithelial to mesenchymal transition (EMT) marker (zinc finger E-box binding homebox 1 (ZEB1)) and an epithelial antigen (cytokeratin (CK)). Molecular analysis of parallel specimens evaluated the KRAS mutation status of the CTC. The survival of each patient after study was recorded. As demonstrated by either cytology or finding of a KRAS mutation, CTC were detected in 18 of 21 patients (86 %) with proven PDAC: 8 out of 10 patients (80 %) with early stage (UICC IIA/IIB) and 10 out of 11 (91 %) with late stage (UICC III/IV) disease. CTC were not found in any of the 10 control patients (p < 0.001). The presence of CTC did not adversely affect median survival: 16 months in CTC-positive (n = 18) vs. 10 months in CTC-negative (n = 3) patients. Neither ZEB1 nor cytological characteristics correlated with overall survival, although ZEB1 was found almost exclusively in CTC of patients with established metastases. Patients with a CTC KRAS mutation (CTC-KRAS (mut)) had a substantially better survival, 19.4 vs. 7.4 months than patients with wild type KRAS (p = 0.015). With ScreenCell filtration, CTC are commonly found in PDAC (86 %). Molecular and genetic characterization, including mutations such as KRAS, may prove useful for prognosis.
authors.affiliation: Department of Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, D-79106, Freiburg, Germany. birte.kulemann@uniklinik-freiburg.de.
authors.forename: Birte
authors.initials: B
authors.lastname: Kulemann
authors.affiliation: Department of Surgery & Andrew L. Warshaw, MD Institute for Pancreatic Cancer Research, Massachusetts General Hospital/ Harvard Medical School, Boston, MA, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Liss
authors.affiliation: Department of Surgery & Andrew L. Warshaw, MD Institute for Pancreatic Cancer Research, Massachusetts General Hospital/ Harvard Medical School, Boston, MA, USA.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Warshaw
authors.affiliation: Department of Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, D-79106, Freiburg, Germany.
authors.forename: Sindy
authors.initials: S
authors.lastname: Seifert
authors.affiliation: Department of Pathology, University of Freiburg Medical Center, Freiburg, Germany.|Comprehensive Cancer Center, University of Freiburg Medical Center, Freiburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Bronsert
authors.affiliation: Department of Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, D-79106, Freiburg, Germany.
authors.forename: Torben
authors.initials: T
authors.lastname: Glatz
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Martha B
authors.initials: MB
authors.lastname: Pitman
authors.affiliation: Department of Surgery, University of Freiburg Medical Center, Hugstetter Str. 55, D-79106, Freiburg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Hoeppner
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics*; D021441:Carcinoma, Pancreatic Ductal / Q000097:blood / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000097:blood / Q000235:genetics* / Q000473:pathology / Q000628:therapy; D010865:Pilot Projects; D011379:Prognosis; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D015996:Survival Rate
chemical_list: D014408:Biomarkers, Tumor; C117307:KRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Circulating tumor cells; Molecular/genetic status; Pancreatic cancer; Prognosis