Fig. 2

Summary of ccfDNA Methylatyion Analyzes. A The concentration of ccfDNA, B The two-time methylation score, and C The two-time recovery score were analyzed in both CRC patients and control subjects (Control). The box plot diagrams show the median as a horizontal line within each box, the interquartile ranges as the box limits, and the maximum and minimum values as the whiskers. P values were calculated using Dunn's test. ROC analyzes were performed to distinguish between CRC patients (n = 97) and control subjects (n = 62) using D The two-time methylation score, E The two-time recovery score, F The combination score (Fc), and G The fivefold cross-validation evaluated by both recovery and methylation scores. H No statistical difference was found between the ROC curve obtained using the combination score (Fc) and the fivefold cross-validation. I Examples of the combination Score (Fc), serum CEA Level, and the sum of the maximum equator of metastatic lesions (the imaging tumor burden) during the clinical course of six mCRC patients receiving systemic chemotherapy and surgical resections. The primary tumor methylation profile shows the methylation ratios at six loci, with R1 and R2 representing Region 1 and Region 2, respectively. Squares denote the heat map of methylation ratios, with black indicating a ratio of 1.0 and white indicating a ratio of 0.0. The number beneath each square represents the methylation ratio. The blue line in the top graph represents the combination score (Fc), while the red line represents the serum CEA level. The gray shade represents the imaging tumor burden. The middle horizontal bar denotes the treatment agent used, with blue, yellow, green, and gray bars representing the first, second, third, and fourth lines, respectively. FL: Fluoropyrimidine; OX: Oxaliplatin; IRI: Irinotecan; CET: Cetuximab; BEV: Bevacizumab; PEM: Pembrolizumab; PANI: Panitumumab. The graphs below show the approximation curves estimated by the combination score (Fc) (blue line), the serum CEA level (red line), and the imaging tumor burden (gray line), respectively