CfDNA-NGS Liquid Biopsy for solid cancers and vascular malformations

The liquid biopsy is a new emerging and repeatable low risky approach able to detect drive mutations that characterize the tumor, to monitor cancer evolution over time, and to overcome the standard tissue biopsy limits. The biomarker par excellence is the circulating cell-free DNA (cfDNA) that was the principal leading actor of this study. The scope of this study was to perform different liquid biopsy analysis both in metastatic cancer and in vascular malformations patients to detect, from a precision medicine perspective, the sniper clone responsible for the tumor evolution or the vascular malformations. The cfDNA was extracted from plasma coming from peripheral and/or efferent vein of vascular malformation. The obtained cfDNA was used to perform the libraries using two different genes panel of 52 and 77 cancer-driver genes, respectively the Oncomine™ Pan-Cancer Cell-Free Assay and AVENIO ctDNA Expanded Kit. The most frequent mutations that we found in metastatic patients were the SNV in TP53, follow by PIK3CA, KRAS, and CNV in FGFR3. In the majority of cases, the mutations found at first liquid biopsy were confirmed by an increased allele frequency at the second one. In vascular anomalies affected patients, the PIK3CA, MET, and KRAS mutated genes were found in Klippel-Trenaunay syndrome, in lymphovenous malformations, and in artero-venous malformations respectively, with a very low allele frequency percentage. In conclusion, repeated analysis of liquid biopsy lead to the identification of key cancer genes and the following of clonal evolution over time. Moreover, the liquid biopsy is suitable not only for cancer patients but also for the diagnosis of vascular malformation. Our data prove that in the new era of precision medicine, this novel approach, based on the combination of NGS and liquid biopsy from the efferent vein at the vascular malformation site, allows to detect even low-grade somatic mosaicism responsible for the vascular phenotype. This approach let to bypassing the need for a highly risky tissue biopsy and lead to a tailored personalized treatment.