Detection of Exfoliated Bladder Cancer Cells Using a Microfluidic Capture Chip - Expert Commentary

Diagnosis, staging, and accurate treatment decisions for patients with bladder cancer require invasive biopsies that are associated with a high cost and risk of complications. Non-invasive liquid biopsy tests using blood or urine offer many advantages for diagnosis and monitoring. For bladder cancer, this can include the detection of urine exfoliated tumor cells (UETCs). In a recent study, Gao et al. tested the efficacy of a microfluidic platform for automated isolation and enrichment of these cells.

For collection, researchers used the CytoBot 2000 platform and a capture chip optimized with a pore size suitable for the target cells. The chip was coated with antibodies targeting specific proteins expressed on epithelial cells and cancer cells: EpCam and T4L6FM1. Additional bladder cancer markers were used to enhance the specificity and accuracy of cell capture, including pan-CK, CK20, and DBC-1. Cell recovery rates were high, at approximately 60%.

Next, researchers tested the procedure on 117 urine samples from patients with bladder cancer and 42 controls. Urine was collected before transurethral resection of bladder tumor (TURBT)
and clinical treatment. The number of detected UETCs varied based on the type of antibody used. More UETCs were found in bladder cancer patients than controls with CK20 or DBC-1 but not pan-CK. In stained samples, pan-CK and CK20 led to better clarity and detection of cell morphology. Sensitivity and specificity rates were excellent for CK20 and DBC-1, as reflected by AUC values of 0.92 and 0.97, respectively. Additional analysis revealed that CK20 and DBC-1 led to the high efficacy of bladder cancer detection (>90%).

The results from this study highlight the value of using an automated microfluidics platform as a non-invasive tool in detecting and monitoring bladder cancer. The technique is practical, yields accurate results, and can potentially minimize invasive procedures. Future studies using this technology can lead to discovering new biomarkers in urine and validating the existing biomarkers.

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

Reference:

  1. Gao F, Wang J, Yu Y, Yan J, Ding G. Comprehensive optimization of urinary exfoliated tumor cells tests in bladder cancer with a promising microfluidic platform [published online ahead of print, 2022 Dec 25]. Cancer Med. 2022;10.1002/cam4.5481. doi:10.1002/cam4.5481
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