1. Institute of Tumor Biology, University Medical Center Hamburg-Eppendorf , Hamburg , Germany
2. Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center , Houston, TX , United States
3. Department of Biostatistics, University of Washington , Seattle, WA , United States
4. Division of Hematology-Oncology, Department of Internal Medicine and the Simmons Comprehensive Cancer Center, Esophageal Diseases Center, University of Texas Southwestern Medical Center , Dallas, TX , United States
5. Department of Pathology, Dana-Farber Cancer Institute , Boston, MA , United States
6. Laboratory of Rare Human Circulating Cells, University Medical Center of Montpellier, University of Montpellier , Montpellier , France