Circulating tumor DNA profiling approach based on in silico background elimination guides chemotherapy in nasopharyngeal carcinoma

Circulating tumor DNA (ctDNA) analysis increasingly provides a promising minimally invasive alternative to tissue biopsies in precision oncology. However, there are no ctDNA analysis approaches available in nasopharyngeal carcinoma (NPC) and current methods of ctDNA mutation profiling have limited resolution because of the high background noise and false‐positive rate caused by benign variants in plasma cell‐free DNA (cfDNA), majorly generated during clonal hematopoiesis. Although personalized parallel white blood cell genome sequencing suppresses the noise of clonal hematopoiesis variances, the system cost and complexity restrict its extensive application in clinical settings. We developed Matched WBC Genome sequencing Independent CtDNA profiling (MaGIC) approaches, which synergically integrated a ctDNA capturing panel for a hybrid capture cfDNA deep sequencing, in silico background elimination, and a reliable readout measurement. We profiled the ctDNAs of 80 plasma samples from 40 patients with NPC before and during chemotherapy by MaGICs. In addition, the public cfDNA sequencing data and The Cancer Genome Atlas project data were analyzed by MaGICs to evaluate their application in other scenarios of patient classification. The MaGIC version‐2 has the ability to predict the chemosensitivity of patients with NPC with high accuracy by utilizing a single sample of liquid biopsy from each patient prior to a standardized treatment regimen. Moreover, both versions of MaGICs are of ideal performance in the diagnosis of patients with prostate cancer by liquid biopsy and prognosis prediction of multiple cancers by tissue biopsy. This study has the potential to enhance the sensitivity and expand the application scope of ctDNA detection, independently of other paired genome sequencing methods. As a result, it might further increase the clinical utilization of liquid biopsy based on ctDNA.