Enumerating Circulating Tumor Cells with a Self-Assembled Cell Array (SACA) Chip: A Feasibility Study in Patients with Colorectal Cancer

Abstract

Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide. Detecting and enumerating circulating tumor cells (CTCs) in patients with colorectal cancer emerged as an important prognostic tool which provides a direct estimate of metastatic potential. Improving the turnaround time and decreasing sample volume is critical for incorporating this liquid biopsy tool into routine practice. The objective of the current study was to validate the clinical feasibility of a self-assembled cell array (SACA) chip, a CTC counting platform with less than 4 h turnaround time, in patients with newly diagnosed colorectal cancers. In total, 179 patients with newly diagnosed colorectal cancers from a single institute were enrolled. Epithelial cell adhesion molecule positive (EpCAM(+)), cluster of differentiation 45 negative (CD45(−)) cells were isolated and enumerated from 2 mL of peripheral vein blood (PB) and inferior mesenteric vein blood (IMV) samples obtained during surgery. We found that the CTC count in PB but not IMV correlates with disease stages. Neoadjuvant chemotherapy did not lead to decreased CTC count in both types of blood samples. With cutoffs of four CTCs per 2 mL of blood, and serum carcinoembryonic antigen (CEA) level of 5 ng/mL, patients with non-metastatic disease were more likely to experience recurrence if they had high PB CTC count and high serum CEA concentration (odds ratio, 8.9). Our study demonstrates the feasibility of enumerating CTCs with a SACA chip in patients with colorectal cancer.

Highly Correlated Recurrence Prognosis in Patients with Metastatic Colorectal Cancer by Synergistic Consideration of Circulating Tumor Cells/Microemboli and Tumor Markers CEA/CA19-9

“…EpCAM (BioMab Inc., Taipei, Taiwan) was used to identify CTC candidates. The details of the process and antibodies were described in a previous work [ 17 ]. The SACA chip system was used in CTC and CTC clusters/microemboli enumeration, and the technical details of the SACA chip were described previously [ 31 ].…”

“…Fluorescent immunoassay was utilized to detect CTCs in accordance with our previous study [ 17 ]. In brief, Hoechst 33258, EpCAM-FITC, and CD45-PECy-7 were used to identify nuclear, EpCAM, and CD45, respectively.…”

“…The number of CTCs in the blood is associated with disease progression in several types of cancer [ 13 , 14 , 15 , 16 ]. Our previous research has shown that the combination of CTC number and CEA levels can improve the precision of cancer prognosis in CRC patients [ 17 ]. Several studies have shown that tumor cells would form CTC clusters/microemboli in the stage of metastasis [ 18 , 19 , 20 ].…”

Determination of the optimal detection time of circulating tumor cells for the postoperative monitoring of colorectal cancer

“…In recent years, liquid biopsy technologies, such as circulating tumor DNA and circulating tumor cell (CTC) detection have substantially advanced the screening and monitoring of CRC (3)(4)(5). CTCs, which shed from carcinoma tissue, have been widely used in the screening and monitoring of cancers, including CRC, breast cancer, small cell lung cancer and other solid tumors.…”

“…CTCs, which shed from carcinoma tissue, have been widely used in the screening and monitoring of cancers, including CRC, breast cancer, small cell lung cancer and other solid tumors. CTC monitoring and screening has been incorporated into the Guidelines for Tumor Staging formulated by the American Joint Committee on Cancer (5)(6)(7)(8). The CTC detection results obtained using a binary-blend fibber-based capture assay are identical to those from the pathological analysis of colonoscopy biopsies (9).…”