Figure 6.

A, Changes in the KRAS mutation allele frequency (MAF) value and the carcinoembryonic antigen (CEA) and carbohydrate antigen 19‐9 (CA19‐9) levels before and after initial course of chemotherapy in pancreatic ductal adenocarcinoma cases in which the KRAS mutation disappeared (N = 8, Pat. #16, 17, 35, 36, 37, 38, 39, 40); cases in which the CEA or CA19‐9 level was not elevated (CEA < 5.0 ng/mL, CA19‐9 < 37.0 U/mL) were omitted. The KRAS‐MAF value and the levels of CEA and CA19‐9 were significantly decreased after initial course of chemotherapy. B, Changes in the KRAS‐MAF value and the CEA and CA19‐9 levels, 1 course of chemotherapy before and after first progressive disease (PD) in cases with KRAS mutation (N = 20); cases in which the CEA or CA19‐9 level was not elevated (CEA < 5.0 ng/mL, CA19‐9 < 37.0 U/mL) and no circulating tumor DNA sample obtained (Pat. #14) were omitted. At the time of the first PD, the KRAS‐MAF value and the levels of CEA and CA19‐9 were significantly increased. C, Changes of KRAS‐MAF value (∆KRAS‐MAF) and those of the CEA and CA19‐9 levels (%change) in each case. ∆KRAS‐MAF significantly correlated with percentage change of CEA or CA19‐9 levels