Longitudinal Analysis of Circulating Tumor Cells in Colorectal Cancer Patients by a Cytological and Molecular Approach: Feasibility and Clinical Application

Alexander Hendricks; Katharina Dall; Burkhard Brandt; Reinhild Geisen; Christian Röder; Clemens Schafmayer; Thomas Becker; Sebastian Hinz; Susanne Sebens

doi:10.3389/fonc.2021.646885

Longitudinal Analysis of Circulating Tumor Cells in Colorectal Cancer Patients by a Cytological and Molecular Approach: Feasibility and Clinical Application

Front Oncol. 2021 Jun 28:11:646885. doi: 10.3389/fonc.2021.646885. eCollection 2021.

Authors

Alexander Hendricks¹, Katharina Dall¹, Burkhard Brandt², Reinhild Geisen³, Christian Röder⁴, Clemens Schafmayer¹, Thomas Becker¹, Sebastian Hinz¹, Susanne Sebens⁴

Affiliations

¹ Department of General, Visceral, Thoracic, Transplantation and Pediatric Surgery, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany.
² Institute of Clinical Chemistry, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany.
³ ORGA Labormanagement GmbH, Ochtrup, Germany.
⁴ Institute for Experimental Cancer Research, Kiel University and University Hospital Schleswig-Holstein Campus, Kiel, Kiel, Germany.

Abstract

Introduction: Liquid biopsies allowing for individualized risk stratification of cancer patients have become of high significance in individualized cancer diagnostics and treatment. The detection of circulating tumor cells (CTC) has proven to be highly relevant in risk prediction, e.g., in colorectal cancer (CRC) patients. In this study, we investigate the clinical relevance of longitudinal CTC detection over a course of follow-up after surgical resection of the tumor and correlate these findings with clinico-pathological characteristics.

Methods: In total, 49 patients with histologically proven colorectal carcinoma were recruited for this prospective study. Blood samples were analyzed for CTC presence by two methods: first by marker-dependent immunofluorescence staining combined with automated microscopy with the NYONE^® cell imager and additionally, indirectly, by semi-quantitative Cytokeratin-20 (CK20) RT-qPCR. CTC quantification data were compared and correlated with the clinico-pathological parameters.

Results: Detection of CTC over a post-operative time course was feasible with both applied methods. In patients who were pre-operatively negative for CTCs with the NYONE^® method or below the cut-off for relative CK20 mRNA expression after analysis by PCR, a statistically significant rise in the immediate post-operative CTC detection could be demonstrated. Further, in the cohort analyzed by PCR, we detected a lower CTC load in patients who were adjuvantly treated with chemotherapy compared to patients in the follow-up subgroup. This finding was contrary to the same patient subset analyzed with the NYONE^® for CTC detection.

Conclusion: Our study investigates the occurrence of CTC in CRC patients after surgical resection of the primary tumor and during postoperative follow-up. The resection of the tumor has an impact on the CTC quantity and the longitudinal CTC analysis supports the significance of CTC as a prognostic biomarker. Future investigations with an even more extended follow-up period and larger patient cohorts will have to validate our results and may help to define an optimal longitudinal sampling scheme for liquid biopsies in the post-operative monitoring of cancer patients to enable tailored therapy concepts for precision medicine.

Keywords: CK20 RT-qPCR; NYONE® cell imager; circulating tumor cells; colorectal cancer; liquid biopsies; longitudinal follow-up.