Comprehensive liquid biopsy analysis as a tool for the early detection of minimal residual disease in breast cancer

Abstract

Liquid biopsy (LB) provides a unique minimally invasive tool to follow-up cancer patients over time, to detect minimal residual disease (MRD), to study metastasis-biology and mechanisms of therapy-resistance. Molecular characterization of CTCs offers additionally the potential to understand resistance to therapy and implement individualized targeted treatments which can be modified during the disease evolution and follow-up period of a patient. In this study, we present a long-term follow-up of operable breast cancer patients based on a comprehensive liquid biopsy analysis. We performed a comprehensive liquid biopsy analysis in peripheral blood of 13 patients with early-stage operable breast cancer at several time points for a period of ten years, consisting of: (a) CTC enumeration using the CellSearch system, (b) phenotypic analysis of CTCs using Immunofluorescence, (c) gene expression analysis, in EpCAM(+) CTCs for CK-19, CD24,CD44, ALDH1, and TWIST1, (d) analysis of PIK3CA and ESR1 mutations in EpCAM(+) CTCs and corresponding plasma ctDNA and (e) DNA methylation of ESR1 in CTCs. 10/13 (77%) patients were found negative for LB markers in PB during the whole follow-up period, and these patients did not relapse during the follow-up. However, 3/13(18%) patients that were positive for at least one LB marker relapsed within the follow-up period. The molecular characteristics of CTCs were highly different even for the same patient at different time points, and always increased before the clinical relapse. Our results indicate that liquid biopsy can reveal the presence of MRD at least 4 years before the appearance of clinically detectable metastatic disease demonstrating that a comprehensive liquid biopsy analysis provides highly important information for the therapeutic management of breast cancer patients.

Circulating tumor cells et al.: towards a comprehensive liquid biopsy approach in breast cancer

“…This association was stronger than the detection of ctDNA alone (hazard ratio =2.99), with similar trends observed for disease-free survival (DFS) and OS when comparing ctDNA+/CTCs+ to ctDNA−/CTCs−. Another recently published study offered insights into the role of comprehensive liquid biopsy analysis for the therapeutic management of EBC patients ( 33 ). Over a ten-year period, the study examined 13 EBC patients through multianalyte liquid biopsy approach, encompassing enumeration, phenotypic characterization, and molecular monitoring of CTCs along with corresponding ctDNA mutation and methylation profile.…”

Research progress of CTC, ctDNA, and EVs in cancer liquid biopsy

“…However, detecting tumor molecular abnormalities through liquid biopsy methods such as ctDNA and CTC indicates the persistence and clinical progression of the tumor ( 191 ). According to studies, liquid biopsies can detect metastatic diseases at least 4 years before they are clinically detected, indicating that thorough liquid biopsy evaluation of CTC combined with ctDNA monitoring MRD can provide very important information for treating and treating patients with breast cancer ( 192 ). Clinical studies have also shown the combination of CTC and ctDNA to improve the sensitivity and specificity of MRD detection in hepatic carcinoma ( 193 ).…”

Detection and Molecular Characterization of Circulating Tumour Cells: Challenges for the Clinical Setting

“…Molecular characterization of CTCs based on gene expression, DNA methylation and DNA mutation analysis in combination with CTC count and phenotypic analysis can reveal the presence of MRD at least 4 years before the appearance of clinically detectable metastatic disease. This indicates that comprehensive liquid biopsy analysis could provide highly important information for the therapeutic management of breast cancer patients at early stages [ 17 ]. A recent study involving 1220 patients with stage I-III BrCa with more than ten-year follow-up has shown that the detection of CK-19 mRNA-positive CTC is prognostic for early relapse, supporting investigations for novel adjuvant therapeutic approaches [ 18 ].…”