Fig. 1: Workflow, assay optimization, and detection of ctDNA/CTCs in pre- and post-NAC blood samples.
From: Increased blood draws for ultrasensitive ctDNA and CTCs detection in early breast cancer patients
a Schema illustrating the study workflow, starting with blood sample collection at breast cancer diagnosis (T1) and subsequent samples after neoadjuvant chemotherapy (NAC) (T2), after surgery (T3), and during follow-up (T4). The diagram also depicts the steps involved in sample processing. b Diagram representing the steps for detecting the presence of ctDNA or CTCs in a plasma or blood cell sample, with specifications provided for the negative controls. c Examples demonstrating improved ctDNA detection in pre-treatment plasma samples using high plasma volumes compared to conventional methods. Mutant droplets are represented by blue dots (FAM-labeled), wild-type droplets by green dots (VIC-labeled), and droplets containing both wildtype and mutant molecules by orange dots. The pink line indicates the threshold for considering FAM-positive droplets. d Violin plots displaying individual values and median variant allele frequencies (VAFs) for ctDNA (orange) and CTCs (red) in pre- and post-NAC blood samples (medians are illustrated as dashed lines and the upper and lower limits of the plots representing the maximum and minimum values, respectively). e Flow chart depicting the number of eligible patients selected for each analysis. NAC Neoadjuvant chemotherapy, PBMCs Peripheral blood mononuclear cells, cfDNA circulating free DNA, ctDNA circulating tumor DNA, CTCs circulating tumor cells, WES Whole exome sequencing, RD Residual disease.
