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Diagnostic Pathology

Open Access

COX-2 expression in thymomas and thymic carcinomas: a novel therapeutic target?

  • RJ Rieker1,
  • PhA Schnabel1,
  • G Mechtersheimer1,
  • M Thomas2,
  • H Dienemann2,
  • P Schirmacher1 and
  • MA Kern1
Diagnostic Pathology20072(Suppl 1):S3

Published: 14 March 2007


Therapeutic TargetThymomaTissue MicroarraysColor IntensityHuman Malignancy


The treatment of advanced stage thymomas and thymic carcinomas is multimodal and includes surgery as well as radiochemotherapy. New therapeutic targets such as EGFR and c-kit are currently under investigation. A number of studies have shown a protumorigenic potential of Cyclooxygenase-2 (COX-2), an enzyme of the prostaglandin metabolism, in a variety of human malignancies, but so far it is unknown whether COX-2 is expressed in epithelial tumors of the thymus.


Using tissue microarrays, the expression of COX-2, microsomal-PGES-1 and -PGES-2 (mPGES-1 and mPGES-2), as well as EGFR was evaluated in thirty-four cases of different subtypes of thymoma and thymic carcinomas. Furthermore, twenty-seven additional cases of thymomas and thymic carcinomas were analysed by COX-2 western immunoblot analysis and compared with six normal thymi from young children.


COX-2 was expressed in all thymoma- and thymic carcinoma subtypes. When measuring the optical color intensity, no significant differences between the subtypes could be detected. A weak correlation between the expression of COX-2, mPGES-1 and mPGES-2 as well as EGFR was found. Western blot analysis of COX-2 expression revealed an up-regulation compared with normal thymus.


COX-2 is expressed in all subtypes of thymomas and thymic carcinomas and represents therefore a potential novel therapeutic target beside EGFR and c-kit. A combined therapy using COX-2 inhibitors in addition to the evolving anti-EGFR antibody therapy may be considered as treatment option, especially when there is no response to established chemotherapeutic schemes, since this combination has a positive impact on the treatment of other malignancies.

Authors’ Affiliations

Institut für allgemeine Pathologie, Universitätsklinikum Heidelberg, Germany
Thoraxklinik Rohrbach am Universitätsklinikum Heidelberg, Germany


© Rieker et al; licensee BioMed Central Ltd. 2007

This article is published under license to BioMed Central Ltd.