Prognostic significance of folate receptor alpha expression in endometrial serous carcinoma: implications for patient stratification and targeted therapy

Abstract Objective To evaluate the clinical significance of folate receptor alpha (FRα) expression in endometrial serous carcinoma. Methods We retrospectively analyzed 47 patients with histopathologically confirmed endometrial serous carcinoma who underwent hysterectomy and received systemic therapy. FRα expression was assessed by immunohistochemistry and categorized as high or low based on ≥ 25% of tumor cells showing moderate-to-strong membranous staining. Associations with clinicopathological variables and survival outcomes were evaluated. Results High FRα expression was observed in 29.8% of cases and was not associated with clinicopathological variables. Patients with high FRα expression had significantly shorter progression-free survival compared with those with low expression (median, 14 vs. 54 months; p = 0.007). In multivariable Cox regression analysis for PFS, high FRα expression remained independently associated with shorter PFS (HR 3.91, 95% CI 1.54–9.94, p = 0.004). No statistically significant difference in overall survival was observed ( p = 0.08). Conclusion High FRα expression was associated with shorter progression-free survival in endometrial serous carcinoma. These findings suggest that FRα expression may represent a biologically relevant marker associated with disease progression and support further investigation in molecularly characterized cohorts.