Prognostic Impact of Estrogen and Progesterone Receptor Expression across Histological Subtypes and Clinical Factors in Epithelial Ovarian Cancer.

Objective: Epidemiological and in vitro studies of epithelial ovarian cancer (OC) strongly suggest a link between hormone receptor (HR) expression, tumorigenesis, and survival. Antihormonal therapies have shown antitumor activity in OC, both alone and combined with other treatments. The primary objective of this study was to examine the expression patterns of estrogen- and progesterone receptors (ER and PR) in OC across different histological subtypes and assess their prognostic value in disease progression.

Design: Retrospective analysis of data from 164 patients who received primary treatment at University Hospital Frankfurt between January 1999 and December 2019.

Materials, setting, methods: The expression of both HRs was determined through immunostaining of tissue samples and evaluated using the immunoreactive score (IRS) according to Remmele and Stegner. Correlation and survival analyses evaluated the prognostic and predictive significance of HR expression.

Results: The correlation between ER and PR expression with histological subtypes was significant (p = 0.002 and p = 0.013, respectively). Strong ER and PR expression was more common in HGSC, low-grade serous carcinoma, and EC, while low PR expression was linked to higher tumor grading (p = 0.032). Notably, clear cell carcinoma patients with weak PR expression had better survival rates than those with strong PR expression (p = 0.025). The difference in overall survival (OS) between ER-positive and ER-negative patients was minimal (55 vs. 51 months; p = 0.906). Median progression-free survival (PFS) and OS were slightly better in cases with weak PR expression (24 and 58 months) compared to strong PR expression (19 and 53 months; p = 0.797 and p = 0.45, respectively). In cases with strong ER expression and suboptimal debulking (TR >1 cm), disease recurrence was delayed (median PFS: 8 vs. 14 months; p = 0.038), a difference not seen after optimal debulking or in overall OS.

Limitations: This single-center, retrospective study limits generalizability. We could not distinguish PR isoforms or assess ER/PR ratios or interactions, limiting molecular insight.

Conclusion: ER and PR expression did not demonstrate a significant overall impact on survival in the entire cohort. However, the expression patterns and associated prognosis of ER and PR differed significantly depending on histological subtypes and clinical factors.