LAUSR

Abstract Background Precision medicine using next gene sequencing (NGS) of tumor tissues has become mainstream of cancer therapy. Liquid biopsy is minimally invasive Method of sampling to assess tumor genotypes, and would be useful for detecting targetable mutations, follow-up during therapy, and detecting relapse, but more data are needed to clarify its significance. We show some preliminary data for liquid biopsy to detect actionable mutations in various cancer patients. Method We analyzed peripheral blood (14 ml) of patients with various cancers resistant to or without standard therapy and purified circulating cell-free DNA and RNA, then sequenced with customized Oncomine Pan-cancer cell free assay to detect actionable mutations in 95 genes. Data would be confirmed with sequencing of cancer tissues if possible, and be followed during therapy. Results From September 2018 to February 2019, 41 patients were analyzed. Of the 41 patients, primary loci of cancer are breast (n = 12), pancreas (n = 7), soft tissue sarcoma (n = 6), uterine (n = 5), head and neck (n = 3), ovary (n = 3), urothelial (n = 2), others (n = 3). The median age was 57 (25-78) years, performance status was 0-1 in all patients. No actionable mutation was detected in 7 patients. In other 34 patients, some significant mutations could be detected. Of those mutations, TP53 mutations were detected in 20 patients, PIK3CA mutations in 10, KRAS mutations in 7, AKT1 mutation in 1, BRAF mutation in 1, MTOR mutation in 1, FGFR3 amplification in 3. Conclusion The results suggest that actionable or druggable mutation can be detected by liquid biopsy using NGS. Further validation with tumor tissue examination and targeting therapy is needed.