Steroid hormone receptor expression in ovarian cancer: progesterone receptor B as prognostic marker for patient survival

Background: There is partially conflicting evidence on the influence of the steroid hormones estrogen (E) and progesterone (P) on the development of ovarian cancer (OC). The aim of this study was to assess the expression of the receptor isoforms ER-alpha/-beta and PR-A/-B in OC tissue and to analyze its impact on clinical and pathological features and patient outcome. Methods: 155 OC patients were included who had been diagnosed and treated between 1990 and 2002. Patient characteristics, histology and follow-up data were available. ER-alpha/-beta and PR-A/-B expression were determined by immunohistochemistry. Results: OC tissue was positive for ER-alpha/-beta in ER-alpha/-beta and 60.1% and PR-A/-B in 36.2% and 33.8%, respectively. We identified significant differences in ER beta expression related to the histological subtype (p=0.041), stage (p=0.002) and grade (p=0.011) as well as PR-A and tumor stage (p=0.03). Interestingly, median receptor expression for ER-alpha and PR-A/-B was significantly higher in G1 vs. G2 OC. Kaplan Meier analysis revealed a good prognosis for ER-alpha positive (p=0.039) and PR-B positive (p<0.001) OC. In contrast, ER-beta negative OC had a favorable outcome (p=0.049). Besides tumor grade and stage, Cox-regression analysis showed PR-B to be an independent prognostic marker for patient survival (p=0.009, 95% CI 0.251-0.823, HR 0.455). Conclusion: ER-alpha/-beta and PR-A/-B are frequently expressed in OC with a certain variability relating to histological subtype, grade and stage. Univariate analysis indicated a favorable outcome for ER-alpha positive and PR-B positive OC, while multivariate analysis showed PR-B to be the only independent prognostic marker for patient survival. In conclusion, ER and PR receptors may be useful targets for a more individualized OC therapy.