Oestrogen receptors are prognostic factors in malignant peritoneal mesothelioma

摘要

Background: Malignant peritoneal mesothelioma (MPM) is a rare and fatal cancer. Females are found to survive longer than males after treatment, suggesting a possible involvement of hormonal factors. Estradiol is involved in cellular proliferation of a number of cancers and acts mainly through oestrogen receptors (ERs). Hence, we examined the expression of oestrogen receptors with correlation to prognosis. Methods: Oestrogen receptors expression was examined using immunohistochemistry on 42 paraffin-embedded sections of MPM tumours. Kaplan-Meier survival curves were analysed to determine the significance of ER expression in relation to prognosis. Results: ER-β (nuclear) was detected in 33 (79 %) patients. ER-β was also detected in the cellular cytoplasm of 9 (21 %) patients. Presence of ER-β (nuclear) was associated with favourable survival (univariate analysis, P = 0.001), whereas the presence of ER-β (cytoplasm) was associated with a poor survival (P = 0.014). Multivariate Cox regression analysis revealed the absence of ER-β (nuclear) and the presence of ER-β (cytoplasm) to be independent predictive factors for poor disease outcome (hazard ratio 5.4, 95 % confidence interval 1.86-15.75; P = 0.002 and hazard ratio 8.0, 95 % confidence interval 1.8-34; P = 0.005), respectively. ER-α (nuclear) was detected in only 4 (9 %) of patients and not statistically significant (univariate analysis, P = 0.066). Conclusion: The presence of ER-β (cytoplasm) is associated with poor prognosis. The favourable survival association observed in patients with ER-β (nuclear) raises a question about the molecular mechanisms of the tumorigenic roles of ER-β in each cellular compartment and requires further studies.