Presence and frequency of rare circulating tumor cells (CTCs) in bloodstreams of cancer patients are pivotal to early cancer detection and treatment monitoring. Here, we use a spiral microchannel with inherent centrifugal forces for continuous, size-based separation of CTCs from blood (Dean Flow Fractionation (DFF)) which facilitates easy coupling with conventional downstream biological assays. Device performance was optimized using cancer cell lines (> 85% recovery), followed by clinical validation with positive CTCs enumeration in all samples from patients with metastatic lung cancer (n = 20; 5–88 CTCs per mL). The presence of CD133+ cells, a phenotypic marker characteristic of stem-like behavior in lung cancer cells was also identified in the isolated subpopulation of CTCs. The spiral biochip identifies and addresses key challenges of the next generation CTCs isolation assay including antibody independent isolation, high sensitivity and throughput (3 mL/hr); and single-step retrieval of viable CTCs.

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The isolation and analysis of circulating cell-free tumor DNA in plasma is a powerful tool with considerable potential to improve clinical outcomes across multiple cancer types, including NSCLC. Assays of this nature that use blood as opposed to tumor samples are frequently referred to as liquid biopsies. An increasing number of innovative platforms have been recently developed that improve not only the fidelity of the molecular analysis but also the number of tests performed on a single specimen. Circulating tumor DNA assays for detection of both EGFR sensitizing and resistance mutations have already entered clinical practice and many other molecular tests - such as detection of resistance mutations for Anaplastic Lymphoma Kinase (ALK) receptor tyrosine kinase rearrangements - are likely to do so in the near future. Due to an abundance of new evidence, an appraisal was warranted to review strengths and weaknesses, to describe what is already in clinical practice and what has yet to be implemented, and to highlight areas in need of further investigation. A multidisciplinary panel of experts in the field of thoracic oncology with interest and expertise in liquid biopsy and molecular pathology was convened by the International Association for the Study of Lung Cancer to evaluate current available evidence with the aim of producing a set of recommendations for the use of liquid biopsy for molecular analysis in guiding the clinical management of advanced NSCLC patients as well as identifying unmet needs. In summary, the panel concluded that liquid biopsy approaches have significant potential to improve patient care, and immediate implementation in the clinic is justified in a number of therapeutic settings relevant to NSCLC.

The enumeration and characterization of circulating tumor cells (CTCs), found in the peripheral blood of cancer patients, provide a potentially accessible source for cancer diagnosis and prognosis. This work reports on a novel spiral microfluidic device with a trapezoidal cross-section for ultra-fast, label-free enrichment of CTCs from clinically relevant blood volumes. The technique utilizes the inherent Dean vortex flows present in curvilinear microchannels under continuous flow, along with inertial lift forces which focus larger CTCs against the inner wall. Using a trapezoidal cross-section as opposed to a traditional rectangular cross-section, the position of the Dean vortex core can be altered to achieve separation. Smaller hematologic components are trapped in the Dean vortices skewed towards the outer channel walls and eventually removed at the outer outlet, while the larger CTCs equilibrate near the inner channel wall and are collected from the inner outlet. By using a single spiral microchannel with one inlet and two outlets, we have successfully isolated and recovered more than 80% of the tested cancer cell line cells (MCF-7, T24 and MDA-MB-231) spiked in 7.5 mL of blood within 8 min with extremely high purity (400-680 WBCs mL(-1); ~4 log depletion of WBCs). Putative CTCs were detected and isolated from 100% of the patient samples (n = 10) with advanced stage metastatic breast and lung cancer using standard biomarkers (CK, CD45 and DAPI) with the frequencies ranging from 3-125 CTCs mL(-1). We expect this simple and elegant approach can surmount the shortcomings of traditional affinity-based CTC isolation techniques as well as enable fundamental studies on CTCs to guide treatment and enhance patient care.