The Impact of Progesterone Receptor Expression on Platinum Sensitivity and Survival Outcomes in Patients With Ovarian Clear Cell Carcinoma
BackgroundOvarian clear cell carcinoma (OCCC) is considered to be a relatively platinum-resistant malignancy. In the present study, we investigated the impact of progesterone receptor (PR) expression on platinum sensitivity and survival outcomes in patients with OCCC.MethodsWe retrospectively reviewed 80 patients with OCCC who underwent surgery followed by adjuvant chemotherapy, and analyzed PR expression by immunohistochemical staining. The PR expression was quantified using the H-score. The
... atinum sensitivity and survival outcomes were compared between those with a weak and strong PR expression. Cisplatin viability experiments were performed in OCCC cell lines (TOV-21G) with different PR expressions.ResultsAmong the 80 patients, 66 and 14 were considered to have platinum-sensitive and platinum-resistant disease, respectively. The mean PR H-score of the platinum-sensitive tumors was significant higher than that of the platinum-resistant tumors (p=0.002). Although there were no significant differences in progression-free and overall survival between the patients with high and low PR expressions, the patients with a high PR expression had a trend towards better survival. In cell models, PR protein was weakly detectable in TOV-21G cells. Through transfection of PR gene, TOV-21G cells were shown to have a strong PR expression by Western blot analysis. After treating the TOV-21G cells with cisplatin, we found that the overexpression of PR enhanced cisplatin cytotoxicity. ConclusionsThe patients in this study with a strong PR expression were associated with better platinum sensitivity and survival, and this was compatible with our experimental findings. The value of PR as a tumor sensitizer to cisplatin in OCCC should be further investigated.