title: A novel approach for the detection and genetic analysis of live melanoma circulating tumor cells.
abstract: BACKGROUND
  Circulating tumor cell (CTC) detection and genetic analysis may complement currently available disease assessments in patients with melanoma to improve risk stratification and monitoring. We therefore sought to establish the feasibility of a telomerase-based assay for detecting and isolating live melanoma CTCs.
  
  
  METHODS
  The telomerase-based CTC assay utilizes an adenoviral vector that, in the presence of elevated human telomerase activity, drives the amplification of green fluorescent protein. Tumor cells are then identified via an image processing system. The protocol was tested on melanoma cells in culture or spiked into control blood, and on samples from patients with metastatic melanoma. Genetic analysis of the isolated melanoma CTCs was then performed for BRAF mutation status.
  
  
  RESULTS
  The adenoviral vector was effective for all melanoma cell lines tested with sensitivity of 88.7% (95%CI 85.6-90.4%) and specificity of 99.9% (95%CI 99.8-99.9%). In a pilot trial of patients with metastatic disease, CTCs were identified in 9 of 10 patients, with a mean of 6.0 CTCs/mL. At a cutoff of 1.1 CTCs/mL, the telomerase-based assay exhibits test performance of 90.0% sensitivity and 91.7% specificity. BRAF mutation analysis of melanoma cells isolated from culture or spiked control blood, or from pilot patient samples was found to match the known BRAF mutation status of the cell lines and primary tumors.
  
  
  CONCLUSIONS
  To our knowledge, this is the first report of a telomerase-based assay effective for detecting and isolating live melanoma CTCs. These promising findings support further studies, including towards integrating into the management of patients with melanoma receiving multimodality therapy.
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Melody J
authors: MJ
authors: Xu
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Mariana
authors: M
authors: Cooke
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: David
authors: D
authors: Steinmetz
authors: Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Giorgos
authors: G
authors: Karakousis
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Deeksha
authors: D
authors: Saxena
authors: Department of Surgery, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Edmund
authors: E
authors: Bartlett
authors: Department of Pathology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Xiaowei
authors: X
authors: Xu
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Stephen M
authors: SM
authors: Hahn
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Jay F
authors: JF
authors: Dorsey
authors: Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America.
authors: Gary D
authors: GD
authors: Kao
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D045744:Cell Line, Tumor; D005260:Female; D005455:Fluorescent Antibody Technique; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016014:Linear Models; D008297:Male; D008545:Melanoma / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D009154:Mutation; D009362:Neoplasm Metastasis; D009360:Neoplastic Cells, Circulating / Q000378:metabolism* / Q000473:pathology; D010865:Pilot Projects; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D012372:ROC Curve; D019098:Telomerase / Q000378:metabolism
chemical_list: C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D019098:Telomerase