CD44⁺/CD24^- Expression as predictors of ovarian cancer chemoresistance: immunohistochemistry and flow cytometry study

Background: The conventional standard treatment for ovarian cancer is not very effective, and the disease is fatal for women. Cancer Stem Cells (CSCs) that express CD44⁺/CD24^- can contribute to chemoresistance and a poor prognosis. We seek to investigate the expression of CSCs (CD44⁺/CD24^-) in ovarian cancer and their predictive significance. Methods: The ambispective cohort was performed on 64 patients (32 patients in each group) at four hospitals (Cipto Mangunkusumo, Tarakan, Fatmawati, and Dharmais Hospital). Debulking surgery was performed on the patients, followed by histopathological analysis. The patients had six rounds of chemotherapy and were under monitoring for six months. The therapeutic responses were evaluated using the RECIST criteria (Response Criteria in Solid Tumors) and categorized as chemoresistant or chemosensitive. Using immunohistochemistry, we directly assess the CSCs from ovarian cancer tissue and using flow cytometry to assess the CSCs from the blood. Results: High CSCs expression and ovarian cancer chemoresistance were significantly related in both trials (p 0.05). A better outcome was obtained using CD44⁺/CD24^- immunohistochemistry. Conclusions: We conclude that there is a substantial association between high CSCs expression and chemoresistance in ovarian cancer and that CSCs immunohistochemistry has a higher predictive value.