A logistic model for the detection of circulating tumour cells in human metastatic colorectal cancer

Abstract

The accuracy in the diagnosis of metastatic colorectal cancer (mCRC) represents one of the challenges in the clinical management of patients. The detection of circulating tumour cells (CTC) is becoming a promising alternative to current detection techniques, as it focuses on one of the players of the metastatic disease and it should provide with more specific and sensitive detection rates. Here, we describe an improved method of detection of CTC from mCRC patients by combining immune-enrichment, optimal purification of RNA from very low cell numbers, and the selection of accurate PCR probes. As a result, we obtained a logistic model that combines GAPDH and VIL1 normalized to CD45 rendering powerful results in the detection of CTC from mCRC patients (AUROC value 0.8599). We further demonstrated the utility of this model at the clinical setting, as a reliable prognosis tool to determine progression-free survival in mCRC patients. Overall, we developed a strategy that ameliorates the specificity and sensitivity in the detection of CTC, resulting in a robust and promising logistic model for the clinical management of metastatic colorectal cancer patients.

Liver Metastasis Is Facilitated by the Adherence of Circulating Tumor Cells to Vascular Fibronectin Deposits

“…Talin1 expression levels in immunoisolated CTCs was performed as described previously (19). Protein tyrosine phosphatase receptor type C (PTPRC or CD45) was used as a reference gene as it detects hematopoietic cells unspecifically isolated, and we have previously reported its validity as a reference gene (19).…”

“…Talin1 expression levels in immunoisolated CTCs was performed as described previously (19). Protein tyrosine phosphatase receptor type C (PTPRC or CD45) was used as a reference gene as it detects hematopoietic cells unspecifically isolated, and we have previously reported its validity as a reference gene (19). C q values (defined as the cycle number at which the fluorescence reached a fixed threshold value) for each transcript were normalized to 40 (maximum number of cycles), and this value to the 40-C q value for CD45 [(40-C q target)-(C q CD45)].…”

Molecular Profiling of Circulating Tumour Cells Identifies Notch1 as a Principal Regulator in Advanced Non-Small Cell Lung Cancer

“…GAPDH , a reference gene previously used for CTC quantification in peripheral blood and indirect evidence of cellularity1146, and HES1 as a downstream gene of NOTCH1 (Supplementary Material and Methods S1) were also included. Mean threshold cycle (depicted as 40-Ct) for every candidate gene was normalized to CD45 , a lymphocyte specific marker that allows the quantification of non-specific isolation and that have been previously used to discriminate the population of CTCs from the total of nucleated cells isolated in blood114748. Samples were run in duplicate and all plates included negative controls.…”

A multimarker panel for circulating tumor cells detection predicts patient outcome and therapy response in metastatic colorectal cancer

“…Coupling CTC isolation with gene expression analyses allowed CTC quantification and molecular characterization at the same time. Related to this, our group and others, recently described qualitative polymerase chain reaction (qPCR)‐based CTC quantification methods, obtaining similar or even higher detection rates compared to CellSearch ® , strengthening CTC prognostic value in mCRC …”