Fig 1.
All samples were collected prospectively. Samples were collected from the following three groups; Surgery, Endoscopy, and Healthy Volunteers. Surgery and Endoscopy groups contain Pre (pre-operative plasma), PBMCs, Tumor, and Post (post-operative plasma) samples. Samples from patients showing Stage IV disease, insufficient sample size, or insufficient extracted DNA amount were excluded from the study (detailed information in text). The color of each box indicates which procedures were used for analysis each type of sample.
Table 1.
Clinicopathologic characteristics of eligible patients; Surgery & Endoscopic groups.
Fig 2.
Sensitivity estimation of the Ion PGM.
The horizontal axis indicates the concentration of spiked DNA from the HCT116 colon cancer cell line in the solution of DNA from a healthy non-cancer donor. HCT116 is known to possess several gene mutations and thus the concentration of the mutation fragment was serially diluted. The vertical axis is the allele frequency that is actually detected with the Ion PGM. Each color point indicates the detected allele frequency of cancer-associated mutations at the corresponding DNA concentration derived from HCT116 ranging from 0.001 to 100%. The names of the mutated genes are indicated in the legend on the right.
Fig 3.
Mutation characteristics of colorectal tumors.
a, Mutation types. Six types of mutations were detected with CHPv2. b, Tumor-unique mutation profile according to allele frequency. Each column denotes a tumor-unique mutation of an individual tumor. Each row denotes cancer-associated genes in CHPv2. The color indicates the variant allele frequency indicated in the color bar.
Fig 4.
Dynamics of MMs and CEA in pre- and post-operation.
a, MMs monitored with the mutation allele frequency using an Ion PGM. Three, one, and three MMs were used for monitoring cases 1, 2, and 3, respectively. The corresponding serum levels of CEA are shown. b, MMs monitored with the mutation allele frequency by ddPCR. One or two MMs were used for monitoring in the represented cases. The horizontal dotted line shows the upper limit of the normal range of CEA serum levels (3.4 ng/ml). Each number adjacent to each data point is the allele frequency for genes; and serum values for CEA. aStop codon, bSplice site.