title: Mutational analysis of single circulating tumor cells by next generation sequencing in metastatic breast cancer.
abstract: Circulating Tumor Cells (CTCs) represent a "liquid biopsy" of the tumor potentially allowing real-time monitoring of cancer biology and therapies in individual patients.The purpose of the study was to explore the applicability of a protocol for the molecular characterization of single CTCs by Next Generation Sequencing (NGS) in order to investigate cell heterogeneity and provide a tool for a personalized medicine approach.CTCs were enriched and enumerated by CellSearch in blood from four metastatic breast cancer patients and singularly isolated by DEPArray. Upon whole genome amplification 3-5 single CTCs per patient were analyzed by NGS for 50 cancer-related genes.We found 51 sequence variants in 25 genes. We observed inter- and intra-patient heterogeneity in the mutational status of CTCs.The highest number of somatic deleterious mutations was found in the gene TP53, whose mutation is associated with adverse prognosis in breast cancer.The discordance between the mutational status of the primary tumor and CTCs observed in 3 patients suggests that, in advanced stages of cancer, CTC characteristics are more closely linked to the dynamic modifications of the disease status.In one patient the mutational profiles of CTCs before and during treatment shared only few sequence variants.This study supports the applicability of a non-invasive approach based on the liquid biopsy in metastatic breast cancer patients which, in perspective, should allow investigating the clonal evolution of the tumor for the development of new therapeutic strategies in precision medicine.
authors.affiliation: Sandro Pitigliani Medical Oncology Department, Hospital of Prato, Istituto Toscano Tumori, 59100, Prato, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Luca
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, 50139, Florence, Italy.
authors.forename: Giada
authors.initials: G
authors.lastname: Rotunno
authors.affiliation: Department of Clinical, Experimental and Biomedical Sciences, University of Florence, 50139, Florence, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Salvianti
authors.affiliation: Sandro Pitigliani Medical Oncology Department, Hospital of Prato, Istituto Toscano Tumori, 59100, Prato, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Galardi
authors.affiliation: Sandro Pitigliani Medical Oncology Department, Hospital of Prato, Istituto Toscano Tumori, 59100, Prato, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Pestrin
authors.affiliation: Sandro Pitigliani Medical Oncology Department, Hospital of Prato, Istituto Toscano Tumori, 59100, Prato, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Gabellini
authors.affiliation: Department of Clinical, Experimental and Biomedical Sciences, University of Florence, 50139, Florence, Italy.
authors.forename: Lisa
authors.initials: L
authors.lastname: Simi
authors.affiliation: Department of Clinical, Experimental and Biomedical Sciences, University of Florence, 50139, Florence, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Mancini
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, 50139, Florence, Italy.
authors.forename: Alessandro Maria
authors.initials: AM
authors.lastname: Vannucchi
authors.affiliation: Department of Clinical, Experimental and Biomedical Sciences, University of Florence, 50139, Florence, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Pazzagli
authors.affiliation: Sandro Pitigliani Medical Oncology Department, Hospital of Prato, Istituto Toscano Tumori, 59100, Prato, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Di Leo
authors.affiliation: Department of Clinical, Experimental and Biomedical Sciences, University of Florence, 50139, Florence, Italy.
authors.forename: Pamela
authors.initials: P
authors.lastname: Pinzani
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000556:secondary; D004252:DNA Mutational Analysis / Q000379:methods*; D005260:Female; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D009154:Mutation; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011379:Prognosis; D059010:Single-Cell Analysis; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: D014408:Biomarkers, Tumor; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53
keywords: breast cancer; circulating tumor cells; next generation sequencing; single cell sequencing; somatic mutations