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Inferring the Evolution and Progression of Small-Cell Lung Cancer by Single-Cell Sequencing of Circulating Tumor Cells

May.23,2019

Dr. Fan Bai, Prof. Sunney Xie published a paper on Clinical Cancer Research with their collaborator.


Purpose: Genomic analyses of small-cell lung cancer (SCLC) are limited by the availability of tumor specimens. This study aimed to investigate the suitability of single-cell sequencing of circulating tumor cells (CTCs) as a method of inferring the evolution and progression of SCLCs. Experimental Design: Between July 1st, 2011 and July 28th, 2014, 48 consecutively diagnosed SCLC patients were recruited for this study. CTCs were captured from each patient with CellSearch system. Somatic mutations and copy number alterations (CNAs) were monitored by single-cell sequencing of CTCs during chemotherapy. Results: Single-cell sequencing of CTCs can provide a mutational atlas for SCLC. A 10-CNA score based on single CTCs was established as a classifier for outcomes of initial chemotherapy in SCLC patients. The survival analyses demonstrated that patients with low CNA scores (<0) had significantly prolonged progression-free survival (PFS) and overall survival (OS) after first-line chemotherapy in comparison with those with high scores (≥0) (PFS: 212 days vs. 110.5 days, p = 0.0042; and OS: 223.5 days vs. 424 days, p = 0.0006). The positive predictive value (PPV) and negative predictive value (NPV) of the CNA score for clinical subtype (refractory vs. sensitive) were 80.0% and 93.7%, respectively. By tracing allele-specific CNAs in CTCs isolated at different time points during chemotherapy, we showed that CNA heterogeneity might result from allelic losses of initially consistent CNAs. Conclusions: Single CTC-based sequencing can be utilized to depict the genomic profiles and evolutionary history of SCLC, thus offering the potential for clinical stratification of SCLC patients.


Original link: http://clincancerres.aacrjournals.org/content/early/2019/05/21/1078-0432.CCR-18-3571