Diagnostic and Clinical Significance of KIT(CD117) Expression in Thymic Epithelial Tumors in China

  • Song, Nan (Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine) ;
  • Chen, Gang (Department of Pathology, Shanghai Pulmonary Hospital, Tongji University School of Medicine) ;
  • Zhang, Peng (Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine) ;
  • Liu, Ming (Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine) ;
  • He, Wen-Xin (Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine) ;
  • Jiang, Ge-Ning (Department of Thoracic Surgery, Shanghai Pulmonary Hospital, Tongji University School of Medicine)
  • Published : 2012.06.30


Aims: To study KIT (CD117) expression in thymic epithelial tumors in China, and investigate diagnostic and clinical significance. Material and Methods: Thymic epithelial tumors (TETs) from 102 patients (3 type A, 29 type AB, 5 type B1, 22 type B2, 29 typeB3 and 16 thymic carcinomas) were examined. Immunohistochemical staining with an antic-kit monoclonal antibody was performed on a tissue microarray. Relationships between KIT positive expression and the TET clinical characteristics (WHO histologic classification and Masaoka stage system) were analysed. Results: The KIT positive expression rate was significantly higher in thymic carcinoma (60%, 9/16) than in thymoma (8%, 7/86), a strong correlation being found with the WHO classification, but not the Masaoka tumor stage. The overall survival for patients with KIT positive lesions was significantly worse. Conclusions: KIT is a good molecule marker to differentially diagnose thymic carcinoma from thymoma, while also serving as a predictor of prognosis for TETs. Further research into KIT mutations in Chinese TETs should be conducted to assess the efficacy of targeted therapy.


Thymoma;thymic carcinoma;thymic epithelial tumors;KIT


  1. Aisner SC, Dahlberg S, Hameed MR, et al (2010). Epidermal growth factor receptor, C-kit,and Her2/neu immunostaining in advanced or recurrentthymic epithelial neoplasms staged according to the 2004 World Health Organization in patientstreated with octreotide and prednisone: an Eastern Cooperative Oncology Group study. J Thorac Oncol, 5, 885-92.
  2. Arbiser JL, Govindarajan B, Bai X, et al (2002). Functional tyrosine kinase inhibitor profiling: a generally applicable method points to a novel role of platelet-derived growth factor receptor-beta in tuberous sclerosis. Am J Pathol, 161, 781-6.
  3. Corless CL, Fletcher JA, Heinrich MC (2004). Biology of gastrointestinal stromal tumors. J Clin Oncol, 22, 3813-25.
  4. de Jong WK, Blaauwgeers JL, Schaapveld M, et al (2008). Thymic epithelial tumours: a population-based study of the incidence, diagnostic procedures and therapy. Eur J Cancer, 44, 123-30.
  5. Edling CE, Hallberg B (2007). c-Kit-a hematopoietic cell essential receptor tyrosine kinase. Int J Biochem Cell Biol, 39, 1995-8.
  6. Giaccone G, Rajan A, Ruijter R, et al (2009). Imatinib mesylate in patients with WHO B3 thymomas and thymic carcinomas. J Thorac Oncol, 4, 1270-3.
  7. Heinrich MC, Rubin BP, Longley BJ, Fletcher JA (2002). Biology and genetic aspects of gastrointestinal stromal tumors: KIT activation and cytogenetic alterations. Hum Pathol, 33, 484-95.
  8. Masaoka A, Yamakawa Y, Niwa H, et al (1994). Thymectomy and malignancy. Eur J Cardiothorac Surg, 8, 251-3.
  9. Muller-Hermelink HK, Engel P, Kuo TT, et al (2004). Tumors of the thymus: introduction. In: Travis, WD.; Brambilla, E.; Muller-Hermelink, HK., et al., editors. Pathology and Genetics. Tumors of the Lung, Pleura, Thymus and Heart. WHO Classification of Tumors. Lyon: IARC Press, p146- 247.
  10. Nakagawa K, Matsuno Y, Kunitoh H, et al (2005). Immunohistochemical KIT (CD117) expression in thymic epithelial tumors. Chest, 128, 140-4.
  11. Pan CC, Chen PC, Chiang H (2004). Overexpression of KIT (CD117) in chromophobe renal cell carcinoma and renal oncocytoma. Am J Clin Pathol, 121, 878-83.
  12. Petrini I, Zucali PA, Lee HS, et al (2010). Expression and mutational status of c-kit in thymic epithelial tumors. J Thorac Oncol, 5, 1447-53.
  13. Strobel P, Bargou R, Wolff A, et al (2010). Sunitinib in metastatic thymic carcinomas: laboratory findings and initial clinical experience. Br J Cancer, 103, 196-200.
  14. Strobel P, Hartmann M, Jakob A, et al (2004). Thymic carcinoma with overexpression of mutated KITand the response to imatinib. N Engl J Med, 350, 2625-6.
  15. Tsuchida M, Umezu H, Hashimoto T, et al (2008). Absence of gene mutations in KIT-positive thymic epithelial tumors. Lung Cancer, 62, 321-5.
  16. Vandenbark GR, de Castro CM, Taylor H, et al (1992). Cloning and structural analysis of the human c-kit gene. Oncogene, 7, 1259-66.

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