Accurate isolation and detection of circulating tumor cells using enrichment-free multiparametric high resolution imaging

Dannel Yeo; Steven Kao; Ruta Gupta; Sara Wahlroos; Althea Bastian; Heidi Strauss; Vera Klemm; Prajwol Shrestha; Arturo B Ramirez; Lillian Costandy; Ryan Huston; Brady S Gardner; Peter Grimison; Jonathan R Clark; John E J Rasko

doi:10.3389/fonc.2023.1141228

Accurate isolation and detection of circulating tumor cells using enrichment-free multiparametric high resolution imaging

Front Oncol. 2023 Mar 27:13:1141228. doi: 10.3389/fonc.2023.1141228. eCollection 2023.

Authors

Dannel Yeo^{1

2

3

4}, Steven Kao^{2

5}, Ruta Gupta^{2

6

7}, Sara Wahlroos⁵, Althea Bastian^{1

2

3

4}, Heidi Strauss^{1

2

3

4}, Vera Klemm^{1

2

3

4}, Prajwol Shrestha^{1

2

4

5}, Arturo B Ramirez⁸, Lillian Costandy⁸, Ryan Huston⁸, Brady S Gardner⁸, Peter Grimison^{2

5}, Jonathan R Clark^{2

6

9}, John E J Rasko^{1

2

3

4}

Affiliations

¹ Li Ka Shing Cell & Gene Therapy Program, The University of Sydney, Camperdown, NSW, Australia.
² Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia.
³ Cell and Molecular Therapies, Royal Prince Alfred Hospital, Sydney Local Health District, Camperdown, NSW, Australia.
⁴ Gene and Stem Cell Therapy Program Centenary Institute, The University of Sydney, Camperdown, NSW, Australia.
⁵ Medical Oncology, Chris O'Brien Lifehouse, Camperdown, NSW, Australia.
⁶ Department of Head and Neck Surgery, Sydney Head and Neck Cancer Institute, Chris O'Brien Lifehouse, Camperdown, NSW, Australia.
⁷ NSW Health Pathology, Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Sydney Local Health District, Camperdown, NSW, Australia.
⁸ RareCyte Inc., Seattle, WA, United States.
⁹ Royal Prince Alfred Institute of Academic Surgery, Sydney Local Health District, Camperdown, NSW, Australia.

Abstract

Introduction: The reliable and accurate detection of rare circulating tumor cells (CTCs) from cancer patient blood samples promises advantages in both research and clinical applications. Numerous CTC detection methods have been explored that rely on either the physical properties of CTCs such as density, size, charge, and/or their antigen expression profiles. Multiple factors can influence CTC recovery including blood processing method and time to processing. This study aimed to examine the accuracy and sensitivity of an enrichment-free method of isolating leukocytes (AccuCyte^® system) followed by immunofluorescence staining and high-resolution imaging (CyteFinder^® instrument) to detect CTCs.

Method: Healthy human blood samples, spiked with cancer cells from cancer cell lines, as well as blood samples obtained from 4 subjects diagnosed with cancer (2 pancreatic, 1 thyroid, and 1 small cell lung) were processed using the AccuCyte-CyteFinder system to assess recovery rate, accuracy, and reliability over a range of processing times.

Results: The AccuCyte-CyteFinder system was highly accurate (95.0%) at identifying cancer cells in spiked-in samples (in 7.5 mL of blood), even at low spiked-in numbers of 5 cells with high sensitivity (90%). The AccuCyte-CyteFinder recovery rate (90.9%) was significantly higher compared to recovery rates obtained by density gradient centrifugation (20.0%) and red blood cell lysis (52.0%). Reliable and comparable recovery was observed in spiked-in samples and in clinical blood samples processed up to 72 hours post-collection. Reviewer analysis of images from spiked-in and clinical samples resulted in high concordance (R-squared value of 0.998 and 0.984 respectively).

Discussion: The AccuCyte-CyteFinder system is as an accurate, sensitive, and clinically practical method to detect and enumerate cancer cells. This system addresses some of the practical logistical challenges in incorporating CTCs as part of routine clinical care. This could facilitate the clinical use of CTCs in guiding precision, personalized medicine.

Keywords: biomarkers; cancer; liquid biopsy; metastasis; precision medicine.

Grants and funding

This work was supported by the Li Ka Shing Cell & Gene Therapy Program (JR); Cancer Council NSW Project Grant RG20-07 (JR); Cancer Council NSW Pathways Grant PW18-03 (JR); National Health & Medical Research Council Investigator Grant 1177305 (JR); CSR Australia project funding (DY, JR), Sydney Cancer Institute Seed Grant (DY), Cancer Institute New South Wales 2020/2081 (JC) and the Sydney Local Health District (JC). DY is the recipient of a Translational Partners Fellowship from Sydney Cancer Partners funded by Cancer Institute New South Wales (2021/CBG0002). The funders had no role in study design, decision to publish, or preparation of the manuscript.