Abstract 3361: Distinct biological response of uterine corpus serous and endometrioid carcinomas to obesity may contribute to differences in clinical outcomes

Despite growing evidence linking obesity to the development and overall survival of cancer patients, the impact of increased body mass index (BMI) on gene expression patterns in gynecologic cancers is unclear. To address this, we herein downloaded RNAseq gene expression data from The Cancer Genome Atlas (TCGA) UCEC (uterine corpus endometrial carcinoma) dataset and matched it with clinical data entries including patient height and weight. We calculated BMI for each patient and used it to stratify patients as normoweight (BMI < 25), overweight (25 ≤ BMI < 30) or obese (BMI ≥ 30). BMI and nutritional status were matched to RNAseq gene expression data. Considering the known differences between endometrioid and serous uterine corpus tumors, analyses were performed separately for endometrioid (n = 356) and serous carcinomas (n = 117). Gene set enrichment analysis (GSEA) was performed between normoweight, overweight and obese patients. GSEA shows that tumors from obese patients display multiple dysregulated Gene Ontology (GO) terms (Biological Process, BP), which also differ between serous and endometrioid tumors. We further explored the impact of obesity on transcriptomic profiles of serous and endometrioid carcinomas by nutritional status independently by differential expression analysis using limma-voom. Significantly up- or downregulated genes were defined as those with logFC ≥ 1.5 at a non-adjusted P-value ≤ 0.01. Despite a clear enrichment or suppression of GO terms as evidenced by GSEA, transcriptomic analyses did not clearly separate patients according to their nutritional status. Therefore, obesity may impact on the dysregulation of biological processes through the cumulative effects of subtle differences in gene expression that, individually, do not seem to play a major role in oncogenesis. These results spotlight the relevance of obesity on the biology of uterine corpus cancers, which impact on the clinical course and treatment response of obese patients is yet to be determined. Funding: This work was supported by CONICYT FONDAP 15130011 (MC, IW), CONICYT-PFCHA/Doctorado Nacional 2019-Folio 21190421 (FG) and FONDECYT 1201083 (MC). Citation Format: Ignacio A. Wichmann, Fernán Gómez, Cristián Salazar, Felipe Suárez, Sumie Kato, Mauricio A. Cuello-Fredes. Distinct biological response of uterine corpus serous and endometrioid carcinomas to obesity may contribute to differences in clinical outcomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3361.