Prognostic Significance of Circulating and Disseminated Tumor Cells in Breast Cancer Patients before and after Adjuvant Chemotherapy.

Objective: Despite the advances in treatment, breast cancer (BC) remains a major cause of death in women. This study aims to evaluate the prognostic significance of detecting circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) in paired peripheral blood (PB) and bone marrow (BM) samples obtained both before and after adjuvant chemotherapy from patients with operable BC.

Materials and methods: In this experimental study, from 160 patients with primary BC, we collected 160 PB and BM samples before and we could be able to collect PB and BM samples from 100 of them after adjuvant chemotherapy. The expression level of cytokeratin 19 (CK19), carcinoembryonic antigen (CEA), mammaglobin 1 (MGB1), mucin 2 (MUC2) and trefoil factor 1 (TFF1) mRNAs in the PB/BM samples were analyzed by quantitative real-time polymerase chain reaction (PCR).

Results: Multivariate Cox regression analyses indicated that the detection of CK19 mRNA-positive CTCs/DTCs either before or after adjuvant chemotherapy was an independent factor for prognosis associated with decreased diseasefree survival (DFS). Patients with tumor cells detected in both PB and BM and patients with persistent detection of tumor cells before and after chemotherapy had worse outcomes compared to those with tumor cells detected in one or neither of the compartments.

Conclusion: This study suggests that the detection of CK19 mRNA-positive CTCs/DTCs either before or after adjuvant chemotherapy could be an independent predictor of DFS in operable BC patients.