THR alpha and its subtypes alpha1 and alpha2 are prognostic markers for survival of ovarian cancer patients

Abstract

Background Ovarian cancer is most lethal in comparison to all other gynecological cancer cases. Within this study, we aimed to investigate the expression of the thyroid hormone receptor alpha and its influence on patient survival in ovarian cancer (OvCa). Methods The presence of the thyroid hormone receptors THRα, THRα1 and -2 were investigated in 156 ovarian cancer samples using immunohistochemistry (IHC) using semi-quantitative immunoreactivity (IR) scores and correlated to clinical, pathological data, subtype of ovarian cancer, clinical data, staining of 20 already described OvCa marker proteins and overall survival (OS). Results Patients with clear cell OvCa showed the highest THRα expression and nuclear THRα expression is associated with reduced survival in this group. In contrast, nuclear expressed THRα1 is a positive prognosticator for all OvCa patients. Nuclear THRα2 is a positive prognosticator for OvCa patients of the serous subtype. Cytoplasmic expression of THRα2 accompanies with reduced OS in all OvCa patients, whereas cytoplasmic expression of THRα1 is associated with reduced OS in mucinous OvCa patients only. In addition, THRα expression correlates to gonadotropin receptors, steroid hormone receptors, TA-MUC1 and glycodelin. Conclusion Thyroid hormones promote ovarian cancer cell proliferation. The further investigation of thyroid hormones and its specific receptors offer the possibility to investigate new endocrine targets against ovarian cancer.