Chapter 4: Analysis of Circulating Tumor DNA in Patients with Cancer: A Clinical Perspective

Somatic genomic alterations are drivers of initiation, progression, and development of resistance to treatment of cancer. Analysis of circulating tumor DNA (ctDNA) enables detection of somatic genomic alteration non-invasively with a simple blood draw. ctDNA analysis may overcome the obstacles of spatial and temporal genomic heterogeneity of cancer and may provide essential information to facilitate an informed clinical decision-making. Emerging evidence has demonstrated clinical utility of ctDNA in directing treatment option, determining prognosis of patients, detecting recurrence of cancer, and detecting early primary cancer. Methods are developed to achieve detection of genomic alterations with high sensitivity and specificity. A brief review of clinical applications of ctDNA analysis is provided.