1. EP3 (prostaglandin E2 receptor 3) expression is a prognostic factor for progression-free and overall survival in sporadic breast cancer.
- Author
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Semmlinger, Anna, von Schoenfeldt, Viktoria, Wolf, Verena, Meuter, Alexandra, Kolben, Theresa Maria, Kolben, Thomas, Zeder-Goess, Christine, Weis, Florian, Gallwas, Julia, Wuerstlein, Rachel, Hermelink, Kerstin, Schmoeckel, Elisa, Harbeck, Nadia, Mayr, Doris, Mahner, Sven, Jeschke, Udo, and Ditsch, Nina
- Subjects
BREAST cancer prognosis ,PROSTAGLANDIN receptors ,GENE expression ,CYCLOOXYGENASE 2 ,CANCER invasiveness ,CLINICAL pathology ,CARCINOGENESIS ,ANIMAL experimentation ,BREAST tumors ,CELL receptors ,COMPARATIVE studies ,GENES ,RESEARCH methodology ,MEDICAL cooperation ,NONSTEROIDAL anti-inflammatory agents ,PROGNOSIS ,RESEARCH ,EVALUATION research ,DISEASE progression ,KAPLAN-Meier estimator ,DINOPROSTONE - Abstract
Background: In various cancers, overexpression of cyclooxygenase (COX)-2 and elevated prostaglandin (PG) E2 synthesis have been associated with tumor development and progression. The potential of COX-2 inhibitors in cancer prevention and treatment has been shown repeatedly; however, their clinical use is limited due to toxicity. PGE2 signals via EP receptors 1-4, whose functions are analyzed in current research in search for targeted anti-PG therapies. EP2 and EP4 rather promote tumorigenesis, while the role of EP3, especially in breast cancer, is not yet clear and both pro- and anti-tumorigenic effects have been described. Our study evaluates EP3 receptor expression in sporadic breast cancer and its association with clinicopathological parameters, progression-free and overall survival.Methods: Two hundred eighty-nine sporadic breast cancer samples without primary distant metastasis were immunohistochemically analyzed for EP3 receptor expression. Tissue was stained with primary anti-EP3-antibodies. Immunoreactivity was quantified by the immunoreactivity-score (IRS); samples with an IRS ≥ 2 scored as EP3 positive. Chi-squared and Mann-Whitney-U test were used for comparison of data; Kaplan-Meier estimates and Cox-regression were used for survival analyses.Results: EP3 receptor was expressed in 205 of 289 samples analyzed (70.9%). EP3 receptor expression was not associated with clinicopathological parameters (e. g. tumor size, hormone receptors, lymph node status). Kaplan-Meier estimates showed a significant association of EP3 positivity with improved progression-free survival (p = 0.002) and improved overall survival (p = 0.001) after up to 10 years. Cox regression analysis confirmed EP3 positivity as a significant prognostic factor even when other known prognosticators were accounted for.Conclusions: In sporadic breast cancer, EP3 receptor expression is not significantly associated with clinicopathological parameters but is a significant prognostic factor for improved progression-free and overall survival. However, the functional aspects of EP3 receptor in breast cancer and the way how EP3 may oppose the pro-tumorigenic effects of PGE2 elevation and COX-2 overexpression are not fully understood so far. Further studies aiming at identification of the factors regulated by EP3 are necessary to evaluate the possibility of targeting EP3 in future anti-tumor therapy in breast cancer. [ABSTRACT FROM AUTHOR]- Published
- 2018
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