1541 - Expression of c-KIT (CD 117) in epithelial thymic malignancies

Date 28 September 2012
Event ESMO Congress 2012
Session Publication Only
Topics Thymoma and Thymic Cancer
Pathology/Molecular Biology
Presenter Mirjana Wollner
Authors M. Wollner1, E. Flechter1, O. Vaisman2, O. Ben Itzhak2
  • 1Department Of Oncology, Rambam Health Care Center, 31096 - Haifa/IL
  • 2Department Of Pathology, Rambam Health Care Center, 31096 - Haifa/IL

Abstract

Study objectives

The expression of c-kit (CD117) was investigated to evaluate its usefulness as a marker supporting differential diagnosis and choice of therapy. In thymic epithelial tumors the expression of c-kit may explain a new model of tumor biology, and support the use of determinate target therapy as a new optional approach.

Methods

We examined the immunohistochemical expression of c-kit in 28 cases of thymic epithelial tumors diagnosed in our department between 2003-2010, that had been classified on the basis of the World Health Organization histologic classification system: 24 thymoma and 4 thymic carcinoma (1 type A, 4 type AB, 1 type B1, 12 type B2, 6 type B3 and 4 type C).

Results

c-kit expression showed immunoreactivity positive in 18% of the all cases (5 patients). In this subgroup, 1 type B2, 1 type B3 and 3 type C. In contrast no immunoreactivity was found in the thymoma cases (types A, AB and B1). No differences were found in the c-kit expressing group between the genders (12 females, 16 males). All c-kit expressing cases were older than 61 years old.

Conclusion

Expression of c-kit is an immunohistochemical marker for the diagnosis of thymic carcinoma, and represent a new model of tumor biology with potential development of new targeted therapies as an option for the treatment of thymic carcinoma on the basis of the kit pathways. Clinical trials are necessary to demonstrate the efficacy of these new theoretical strategies.

Disclosure

All authors have declared no conflicts of interest.