A multi-level investigation of the genetic relationship between endometriosis and ovarian cancer histotypes

Abstract

Endometriosis is associated with increased risk of epithelial ovarian cancers (EOCs). Data from large endometriosis and EOC genome-wide association meta-analyses were used to estimate the genetic correlation and evaluate the causal relationship between genetic liability to endometriosis and major EOC histotypes, and to identify shared susceptibility loci. We estimated a significant genetic correlation (rg) between endometriosis and clear cell (rg=0.71), endometrioid (rg=0.48) and high-grade serous (rg=0.19) ovarian cancer, all supported by Mendelian randomization analyses. A bivariate meta-analysis identified 28 loci associated with endometriosis and EOC, including two novel risk loci, and 19 with evidence for a single underlying causal variant. Differences in the shared risk suggest different underlying pathways may contribute to the relationship between endometriosis and the different histotypes. Functional annotation using transcriptomic and epigenomic profiles of relevant tissues/cells highlighted several target genes. This comprehensive analysis reveals profound genetic overlap between endometriosis and EOC histotypes with valuable genomic targets for understanding the biological mechanisms linking the diseases.