DNA Methylation Profiling Enables Subclassification of Mucinous Ovarian Carcinoma and Distinguishes It from Extraovarian Mucinous Metastases
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ABSTRACT: Mucinous ovarian carcinoma (MOC) is a rare and poorly characterized subtype of epithelial ovarian cancer. Pathogenetically, it is the only epithelial ovarian carcinoma for which the cell of origin remains unknown. Clinically, MOC presents a significant diagnostic challenge due to its close morphological resemblance to extraovarian metastases (EOM) involving the ovary. Accurate diagnosis is critical, as it directly informs treatment decisions. To improve our understanding of MOC and enhance its diagnostic accuracy, we performed genome-wide DNA methylation profiling on MOC (n = 58), EOM (n = 38), and mucinous borderline ovarian tumors (mBOT, n = 18) collected from three institutions. We developed a machine-learning pipeline based on DNA methylation data to support this challenging differential diagnosis. Our analysis revealed two distinct subtypes of mBOT—one epigenetically similar to normal ovary and the other to MOC—supporting the stepwise progression of mBOT to MOC. Furthermore, we identified two clinically relevant DNA methylation subtypes of MOC with prognostic implications, enabling molecular stratification of patients. Using these data and 389 additional DNA methylation profiles, we developed and validated a three-step molecular classifier. In the first step, MOC was identified with an accuracy of 98.04%. In the second step, EOM was detected and non-mucinous lesions excluded with 97.6% accuracy. In the third step, the tissue of origin for EOM was predicted with 86.27% accuracy. Overall classifier accuracy of all three steps was 89.07%. Additionally, we demonstrated the feasibility of implementing the classification process with nanopore sequencing, though high tissue quality remains essential. In conclusion, we identified two prognostically significant subtypes of MOC based on DNA methylation and developed a robust machine learning-based classifier that distinguishes MOC from EOM with high accuracy. These findings have the potential to improve diagnostic precision and guide therapeutic strategies.
ORGANISM(S): Homo sapiens
PROVIDER: GSE310580 | GEO | 2026/05/27
REPOSITORIES: GEO
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