Metadata supporting data files in the published article: The acute effects of adjuvant radiation and chemotherapy on peripheral blood epigenetic age in early stage breast cancer patients

In this study, the authors examined epigenetic changes in peripheral whole blood cells in early stage breast cancer (BC) patients undergoing surgery followed by adjuvant radiotherapy, or surgery followed by adjuvant chemotherapy and radiotherapy. <b>Data access: </b>The dataset RISEdataTab1.xlsx supporting Table 1 of the published article is publicly available in the figshare repository as part of this data record. Methylation data supporting Figure 1 and Supplementary Figure 2 of the published article are publicly available in the <i>Gene Expression Omnibus </i>repository, via accession https://identifiers.org/geo:GSE140038. The filenames and types are as follows: NormalizedBetaNoob.csv, GSM4151814-GSM4151957 (in idat format), and Data Dictionary.docx.<br> <b>Study approval and patient consent</b>:This study was approved by the UCLA Medical Institutional Review Board. Informed consent was obtained from all participants. <b>Study aims and methodology</b>:The aim of this study was to examine the acute effects of adjuvant radiation and chemotherapy on peripheral blood epigenetic age in early stage breast cancer patients. Women were eligible for the study if they had been recently diagnosed with Stage 0-IIIA BC and had not yet started adjuvant or neoadjuvant therapy with radiation, chemotherapy, or endocrine therapy. Assessments were conducted before onset of adjuvant therapy, after completion of radiation and/or chemotherapy, and over an 18-month follow-up. The current analysis focuses on a subset of women (n=72) who had blood samples available for epigenetic analyses at baseline and post-treatment. The women selected were treated with radiation alone (n=37), and with chemotherapy followed by radiation (n=35), to evaluate individual and combined effects of those treatment exposures. All women had completed surgery prior to the baseline assessment. Four measures of epigenetic age acceleration were examined: intrinsic (IEAA), extrinsic (EEAA), phenotypic (PEAA), and Grim (GEAA), based on weighted averages of methylation levels at 353, 71, 513, and 1,030 CpGs, respectively, with adjustment for chronologic age. Details of the epigenetic clock, DNA extraction/methylation experiments, and statistical analyses are provided in the supplementary methods.