title: Circulating tumor cells following first chemotherapy cycle: an early and strong predictor of outcome in patients with metastatic breast cancer.
abstract: We investigated the prognostic significance of circulating tumor cells (CTCs) determined immediately before the second cycle of chemotherapy in patients with metastatic breast cancer (MBC). The CTC counts were taken at baseline, before the first cycle of chemotherapy (CTC-0), and on day 21 before commencing the second cycle of chemotherapy (CTC-21) in consecutive MBC patients. The study's primary objectives were to analyze relationships between CTC-21 count and overall survival (OS). Based on the current literature, the CTC measurements were dichotomized as 0-4 versus ≥ 5 CTCs. Of 117 patients recruited, 99 were evaluable. Patients with 0-4 CTCs on day 21 had a significantly better OS than those with ≥ 5 CTCs (median OS: 38.5 months vs. 8.7 months). They also had a significantly better progression-free survival (PFS; median: 9.4 months vs. 3.0 months) and clinical benefit rate (77% vs. 44%). The OS of patients whose baseline CTCs were ≥ 5 but dropped to <5 on day 21 was apparently similar to those who had <5 CTCs at baseline. In a Cox regression analysis, CTC-21 was the only independent variable significantly predicting OS and PFS. Our data indicate that CTCs determined immediately before the second cycle of chemotherapy is an early and strong predictor of treatment outcome in MBC patients.
authors.affiliation: Medical Oncology Service, Instituto de Investigación Sanitaria Hospital Gregorio Marañón, Universidad Complutense, Madrid, Spain. mmartin@geicam.org
authors.forename: Miguel
authors.initials: M
authors.lastname: Martín
authors.forename: Sara
authors.initials: S
authors.lastname: Custodio
authors.forename: Maria-Luisa Maestro
authors.initials: ML
authors.lastname: de Las Casas
authors.forename: José-Ángel
authors.initials: JÁ
authors.lastname: García-Sáenz
authors.forename: Julio-César
authors.initials: JC
authors.lastname: de la Torre
authors.forename: Jose-María
authors.initials: JM
authors.lastname: Bellón-Cano
authors.forename: Sara
authors.initials: S
authors.lastname: López-Tarruella
authors.forename: Marta
authors.initials: M
authors.lastname: Vidaurreta-Lazaro
authors.forename: Virginia
authors.initials: V
authors.lastname: de la Orden
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Jerez
authors.forename: Iván
authors.initials: I
authors.lastname: Márquez-Rodas
authors.forename: Antonio
authors.initials: A
authors.lastname: Casado
authors.forename: Javier
authors.initials: J
authors.lastname: Sastre
authors.forename: Eduardo
authors.initials: E
authors.lastname: Díaz-Rubio
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000473:pathology*; D011379:Prognosis; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: Circulating tumor cells; Metastatic breast cancer; Outcome prediction