Figure 6 from Genomic Landscapes of Endometrioid and Mucinous Ovarian Cancers and Morphologically Similar Tumor Types

<p>Ovarian endometrioid carcinomas are epigenetically similar to healthy uterine endometrium, whereas ovarian mucinous carcinomas are mixed with both mucinous- and endometrial-like signatures. <b>A,</b> We trained a LD model for the classification of samples as stomach mucinous, colorectal mucinous, or uterine endometrial from variably methylated CpG sites in TCGA samples. Ellipses denote the 95th percentile of the bivariate normal distribution for each of these histology classifications. <b>B,</b> Using the LD model from (<b>A</b>), the histologic classifications of samples were obtained and overlaid on the ellipses redrawn from <b>A</b>. The co-clustering of colorectal and stomach mucinous carcinomas with the corresponding tumor types from TCGA confirm that the methylation patterns that separate these tissues in TCGA broadly reflect histology differences (top). Whereas ovarian mucinous and ovarian endometrioid samples have no counterpart in TCGA (bottom), we evaluated whether these samples would be epigenetically similar to their morphologic counterparts in TCGA. <b>C,</b> Class probabilities from the LD model evaluated on the analyzed samples. As expected, patients with stomach and colorectal mucinous carcinomas were correctly classified as mucinous, and patients with ovarian endometrioid carcinomas were correctly classified as endometrial. Interestingly, classification of patients with ovarian mucinous carcinoma was more heterogenous, with nearly half of the samples exhibiting a mucinous signature and the remaining samples bearing more of a resemblance to endometrial methylation patterns. The two colorectal mucinous samples in <b>B</b> (top left) were sequencing replicates from a single patient’s tumor (patient CGCRC330).</p>