Title : Cytopathological assessment is an accurate method for identifying immunophenotypic features and BRCA1/2 mutations of high-grade serous carcinoma from ascites
Abstract:
Background: High-grade serous carcinoma (HGSC) is the most common and aggressive type of ovarian cancer, and is often associated with ascites at presentation. Our objective was to evaluate the accuracy of cytopathology to identify immunophenotypic features of HGSC and BRCA1/2 mutations from ascites. Methods: The study included 45 patients with histologically confirmed primary HGSC and malignant ascites. Immunocytochemical (ICC) staining for PAX8, WT1, P53, P16 and Ki67 was performed on cytospins and cytoblocks prepared from ascites. Next-Generation Sequencing (NGS) was used to detect germline/somatic BRCA1/2 mutations in the ascites. Both ICC and NGS results were compared to immunohistochemical (IHC) and NGS results from tissue blocks of primary tumor. Cronbach’s α and Chi-square statistics were used, respectively. Results: ICC/IHC results for PAX8, WT1, P53, and P16 showed good reliability between cytospins, cytoblocks and tissue blocks (α>0.75), whereas poor reliability and significant difference were observed for Ki67 between ascites and tissue blocks (α<0.26, p<0.001). A 100% concordance was confirmed for germline BRCA1/2 mutations, but only 14% concordance for somatic mutations. Conclusion: Our results demonstrate that cytopathology is an accurate method for identifying immunophenotypic features of HGSC and detecting germline BRCA1/2 mutations from ascites. However, further investigation is required for assessing the proliferation activity of HGSC in ascites as well as detecting somatic BRCA1/2 mutations.
