Prognostic Value of a Three-DNA Methylation Biomarker in Patients with Soft Tissue Sarcoma

Figure 1

Data cleaning steps for STS DNA methylation data. In the bracket of each box, the number of samples was on the left and the number of methylation sites on the right. The total data of 269 STS samples and 485577 methylation sites were downloaded from the TCGA database. First of all, 4 normal samples were removed, as this study aimed to investigate the prognosis of STS patients. Among the remaining 265 tumor samples, 5 other types of solid tumor samples were dropped, which included 3 recurrent solid tumor samples, 1 metastatic solid tumor sample, and 1 primary solid tumor sample obtained from formalin-fixed paraffin-embedded tissue that was proven to be ineffective for sequencing analysis. As a result, 260 primary solid tumor samples were retained. To avoid possible misunderstandings on the follow-up survival time of STS patients, 3 samples with a survival time of 0 days were excluded. Meanwhile, all the DNA methylation sites containing 'NA' values were removed. Finally, a total of 257 samples with clinical information and 374831 DNA methylation sites were preserved for subsequent analysis.