927 Identification of proteomic signatures for early ovarian cancer in BRCA-mutated patients

Introduction/Background We aim to analyze stage I ovarian cancer and ovarian cancer precursor lesions with BRCA mutation to identify a specific proteomic signature that contributes to the onset of early ovarian cancer. Methodology We analyzed a total of 20 Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples from patients with Serous Tubal Intraepithelial Carcinoma (STIC) and Stage 1 ovarian cancer, as well as 10 adjacent normal tissue FFPE samples. Proteome analysis was conducted using liquid chromatography-mass spectrometry. We analyzed the performance of selected proteins. Results The proteins that exhibited the most significant upregulation were Periostin, Keratin 7, and Calcyphosin, while the proteins showing the most significant downregulation were DHRS2, LTBP2, and ENPP6. Periostin exhibited a sensitivity of 95% and specificity of 100%, with an area under the ROC curve (AUC) of 0.960. CAPS showed a sensitivity of 100%, specificity of 100%, and an AUC of 1.00. FOLR1 has been increased with a specificity of 100% sensitivity of 80% and an AUC of 0.855. DHRS2 has been decreased with a specificity and sensitivity of 100% and an AUC of 1.00. DHRS2 has been decreased with a sensitivity of 100% and an AUC of 0.97. Conclusion Through proteome analysis, we discovered proteins with high specificity and sensitivity, such as Periostin, CAPS, FOLR1, DHRS2, and LTBP2, for diagnosing early ovarian cancer in patients with BRCA mutations. In the future, if we confirm that these proteins can also be secreted in the blood, there may be potential for them to serve as monitoring biomarkers using patient blood. Disclosures This study was supported by a grant (2022IP0094) from the Asan Institute for Life Sciences, Asan Medical Center, Seoul, Korea.