Circulating Tumor DNA After Neoadjuvant Chemotherapy

"Sequential plasma samples for ctDNA mutations analysis will be taken during the post-surgery visit (within 2-5 weeks after surgery) and every 6 months (+/- 1 month) thereafter for 5 years. In case of relapse patients will be proposed to participate to an optional research program with a blood test for ctDNA assessment and biopsies from a metastasis (when these biopsies are clinically indicated). Next Generation Sequencing (NGS) analysis will be performed on post-neoadjuvant chemotherapy residual tumor tissue samples. The mutations identified by NGS in residual tumor will be tracked in ctDNA using personalized digital PCR (dPCR) or by an NGS technique whose bioinformatics pipeline is adapted to the analysis of ctDNA.~In case of relapse patients will be proposed to participate to an optional research program with a blood test for ctDNA assessment and biopsies from a metastasis (when these biopsies are clinically indicated)."