This online seminar discussed sample collection challenges associated with tumor sequencing, with a particular focus on somatic variant testing in plasma. The session also featured recent evidence demonstrating that circulating tumor DNA is a broadly applicable, sensitive, and specific biomarker that can be used for a variety of clinical and research purposes in patients with multiple different types of cancer.

Liquid biopsies are emerging as a non-invasive alternative to tumor tissue testing and are likely to be rapidly incorporated into clinical care. Applying next-generation sequencing to liquid biopsies allows the detection of multiple gene mutations in ctDNA extracted from plasma without prior knowledge of the mutation(s) that may be present. NGS analysis of ctDNA in plasma holds much promise for improving cancer diagnosis and monitoring.

During the webinar, Chetan Bettegowda of Johns Hopkins University School of Medicine discussed a study that evaluated the ability of ctDNA to detect tumors in 640 patients with various cancer types. Dr. Bettegowda detailed the findings of the study, which found that ctDNA was often present in patients without detectable circulating tumor cells, suggesting that these two biomarkers are distinct entities.

This webinar also discussed the sample requirements for somatic variant testing in plasma and metrics for measuring sample quality in plasma. This is of central importance when attempting to detect minute fractions of tumor-derived DNA.