Expanded Genomic Profiling of Circulating Tumor Cells in Metastatic Breast Cancer Patients to Assess Biomarker Status and Biology Over Time (CALGB 40502 and CALGB 40503, Alliance)

Abstract

We profiled circulating tumor cells (CTCs) to study the biology of blood-borne metastasis and to monitor biomarker status in metastatic breast cancer (MBC). CTCs were isolated from 105 patients with MBC using EPCAM-based immunomagnetic enrichment and fluorescence-activated cells sorting (IE/FACS), 28 of whom had serial CTC analysis (74 samples, 2-5 time points). CTCs were subjected to microfluidic-based multiplex QPCR array of 64 cancer-related genes ( = 151) and genome-wide copy-number analysis by array comparative genomic hybridization (aCGH; = 49). Combined transcriptional and genomic profiling showed that CTCs were 26% , 48%, and 27% Serial testing showed that status was more stable over time compared with and proliferation () status. While cell-to-cell heterogeneity was observed at the single-cell level, with increasingly stable expression in larger pools, patient-specific CTC expression "fingerprints" were also observed. CTC copy-number profiles clustered into three groups based on the extent of genomic aberrations and the presence of large chromosomal imbalances. Comparative analysis showed discordance in /ER (27%) and/HER2 (23%) status between CTCs and matched primary tumors. CTCs in 65% of the patients were considered to have low proliferation potential. Patients who harbored CTCs with high proliferation () status had significantly reduced progression-free survival ( = 0.0011) and overall survival ( = 0.0095) compared with patients with low proliferative CTCs. We demonstrate an approach for complete isolation of EPCAM-positive CTCs and downstream comprehensive transcriptional/genomic characterization to examine the biology and assess breast cancer biomarkers in these cells over time. .

Analysis of the serial circulating tumor cell count during neoadjuvant chemotherapy in breast cancer patients

“…Patients with more than 5 CTCs after NCT displayed a worse outcome. Given that CIBOMA/2004-01/ GEICAM/2003-11 trial (ClinicalTrials.gov number, NCT00130533) 13 fail to show a significant survival benefit of adjuvant capecitabine, except in non-basal subgroup 13 , molecular analysis of CTCs, such as genomic profiling 47,48 may able to provide useful information that can help find a patient may benefit from the therapy. As patients with the residual disease with no CTCs displayed better outcomes than patients presenting CTCs after NCT, the benefit of additional adjuvant chemotherapy might be profound in those specific groups.…”

Circulating tumor cells and breast cancer‑specific mutations in primary breast cancer

“…In a study including 216 patients, 12 genes (TP53, PIK3CA, GATA3, ESR1, MAP3K1, CDH1, AKT1, MAP2K4, RB1, PTEN, CBFB and CDKN2A) were established as significantly mutated in metastatic breast cancer (mBC), while 8 genes (ESR1, FSIP2, FRAS1, OSBPL3, EDC4, PALB2, IGFN1 and AGRN) were more frequently mutated in mBC as compared to early breast cancer (17). Several published studies have investigated the mutational status of CTCs (18)(19)(20)(21); however, data on the association between gene mutations in primary tumor tissue and the presence of CTCs in the peripheral blood are lacking.…”

Current progress in the clinical use of circulating tumor cells as prognostic biomarkers

“…These include immunoaffinity analysis (for markers including EpCAM, CD15, CD45, and CD66b); techniques for the analysis of biophysical characteristics such as size, deformability, density, and surface charge; immunofluorescence for quantification; and molecular techniques including sequence analysis for genomics and transcriptomics, mass cytometry for proteomic analysis, and targeted bisulfite sequencing for epigenetic analysis . Table highlights the potential of CTCs as biomarkers for disease progression, prognosis, and outcomes for a wide range of cancers . Figure summarizes the potential prognostic role of CTCs at various stages of cancer.…”

“…4 Table 1 highlights the potential of CTCs as biomarkers for disease progression, prognosis, and outcomes for a wide range of cancers. [18][19][20][21][22][23][24][25][26][27][28][29][30][31] Figure 1 summarizes the potential prognostic role of CTCs at various stages of cancer.…”