Abstract B45: High-throughput label-free isolation and expansion of circulating tumor cells (CTCs) from non-small cell lung cancer (NSCLC) patients for personalized treatments

Background: Circulating tumor cell (CTC) clusters are emerging as clinically significant harbingers of metastases in solid organ cancers. Prior to engaging these CTC clusters in animal models of metastases, it is imperative for technology to identify them with high sensitivity. These clusters often present heterogeneous surface markers, and current methods for isolation of clusters may fall short.

Methods: We have applied the inertial microfluidic Labyrinth device for high-throughput, biomarker-independent, size-based isolation of CTCs and CTC clusters from patients with metastatic non-small cell lung cancer (NSCLC).

Results: Using the Labyrinth device, CTCs (PanCK+/DAPI+/CD45-) were isolated from metastatic NSCLC patients (n=25). Heterogeneous CTC populations were detected, including CTCs expressing epithelial (EpCAM), mesenchymal (vimentin), or both markers. CTCs were isolated from 100% of patients (417±1023 CTCs/mL), and CTCs that were EpCAM negative were significantly higher in numbers than EpCAM+ CTCs. Cell clusters of ≥2 CTCs were observed in 96% of patients, of which 75% were negative for EpCAM. Patients with higher number of CTC clusters than single CTCs had worse progression-free survival (PFS) (p=0.05). Recovered CTCs from patients with RET, ROS1, and ALK-rearranged tumors revealed identical genetic aberrations as the primary tumor for each gene using FISH analysis. We have successfully expanded the recovered CTCs from 2 patients and screened for therapeutic targeting. We have found that TPX-0005 might be effective in these patients and would direct them to a clinical trial using this compound.

Conclusions: The label-free Labyrinth device demonstrated the capability of collecting recovered CTCs from the device using a continuous processing technique while in a suspension state. This advantage opens the opportunities not only for CTC expansion off-chip, but also for ex vivo drug testing to direct patient-specific therapies.

Citation Format: Mina Zeinali, Wei Huang, Maggie Lee, Arthi Nadhan, Anvya Mathur, Casey Hedman, Eric Lin, Ramdane Harouaka, Max S. Wicha, Lili Zhao, Nallasivam Palanisamy, Mathias Hafner, Rishindra Reddy, Gregory P. Kalemkerian, Bryan J. Schneider, Khaled A. Hassan, Nithya Ramnath, Sunitha Nagrath. High-throughput label-free isolation and expansion of circulating tumor cells (CTCs) from non-small cell lung cancer (NSCLC) patients for personalized treatments [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B45.

High-Throughput Label-Free Isolation of Heterogeneous Circulating Tumor Cells and CTC Clusters from Non-Small-Cell Lung Cancer Patients

(1) Background: Circulating tumor cell (CTC) clusters are emerging as clinically significant harbingers of metastases in solid organ cancers. Prior to engaging these CTC clusters in animal models of metastases, it is imperative for technology to identify them with high sensitivity. These clusters often present heterogeneous surface markers and current methods for isolation of clusters may fall short. (2) Methods: We applied an inertial microfluidic Labyrinth device for high-throughput, biomarker-independent, size-based isolation of CTCs/CTC clusters from patients with metastatic non-small-cell lung cancer (NSCLC). (3) Results: Using Labyrinth, CTCs (PanCK+/DAPI+/CD45−) were isolated from patients (n = 25). Heterogeneous CTC populations, including CTCs expressing epithelial (EpCAM), mesenchymal (Vimentin) or both markers were detected. CTCs were isolated from 100% of patients (417 ± 1023 CTCs/mL). EpCAM− CTCs were significantly greater than EpCAM+ CTCs. Cell clusters of ≥2 CTCs were observed in 96% of patients—of which, 75% were EpCAM−. CTCs revealed identical genetic aberrations as the primary tumor for RET, ROS1 , and ALK genes using fluorescence in situ hybridization (FISH) analysis. (4) Conclusions: The Labyrinth device recovered heterogeneous CTCs in 100% and CTC clusters in 96% of patients with metastatic NSCLC. The majority of recovered CTCs/clusters were EpCAM−, suggesting that these would have been missed using traditional antibody-based capture methods.

Abstract 1332: High Throughput isolation and expansion of circulating tumor cells (CTCs) from Non-small cell lung cancer (NSCLC) patients for personalized treatments

Background: Circulating tumor cells (CTCs) have emerged as important blood-based surrogate markers of primary tumors. Current methods for isolation of lung CTCs mostly rely on biomarker dependent antibody-based capture, missing populations that may be stem-like in nature. Results: We have applied the microfluidic Labyrinth device for high throughput, label-free, size-based isolation of CTCs from non-small cell lung cancer patients (NSCLC). The Labyrinth device was optimized and tested for inertial separation of cancer cells using the human lung cancer cell line H1650. The recovery and purity were >82% and >78%, respectively, operating at a flow rate of 2.5 mL/min. Using the biomarker-independent Labyrinth separation device, heterogeneous CTC populations were isolated from metastatic NSCLC patients (n=21). Heterogeneous CTC populations were detected, including CTCs (PanCK+ and CD45-), CTCs expressing EpCAM or Vimentin, and CTCs expressing both markers representing an EMT-like population of CTCs. Using Labyrinth, we were able to isolate CTCs from 100% of patients with an average yield of 180±168 CTCs/mL. Among the captured CTCs, EpCAM- CTCs were significantly more common than EpCAM+ CTCs (115.7 vs. 39.1 CTCs/mL respectively). Cell clusters of 2 or more CTCs were also observed in 95% of patients; 79% of these clusters were negative for EpCAM expression, whereas 35% expressed Vimentin, suggestive of an EMT phenotype. Recovered CTCs from patients with RET, ROS1 and ALK rearranged tumors showed aberrations matching with the primary tumor for each gene using FISH analysis. We have successfully expanded the recovered CTCs from 2 patients and screened for therapeutic targeting. We have found that TPX-0005 might be effective in these patients and would direct them to a clinical trial using this compound. Conclusion: The label-free Labyrinth device demonstrated the capability of collecting recovered CTCs from the device using a continuous processing technique while in a suspension state. This advantage opens the opportunities not only for CTC expansion off-chip, but also for ex-vivo drug testing to direct patient-specific therapies.

Citation Format: Mina Zeinali, Maggie Lee, Arthi Nadhan, Anvya Mathur, Wei Huang, Eric Lin, Ramdane Harouaka, Max S. Wicha, Nallasivam Palanisamy, Mathias Hafner, Rishindra Reddy, Gregory P. Kalemkerian, Bryan J. Schneider, Khaled A. Hassan, Nithya Ramnath, Sunitha Nagrath. High Throughput isolation and expansion of circulating tumor cells (CTCs) from Non-small cell lung cancer (NSCLC) patients for personalized treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1332.