Absence of gene mutations in KIT-positive thymic epithelial tumors

Molecular aspects of thymic carcinoma

“…Collectively, the percentage of c-kit positive cases averages 62.8% [3,[13][14][15][16]21,[26][27][28][29][30][31][32]. Contrary to the relatively high protein expression however, c-kit mutation is a rare event in thymic carcinomas (<10%) [13,14,19,21,26,28,29,31]. Among the mutation positive cases [13,14,19,26], two showed a partial response to treatment with the TKIs imatinib [26] and sorafenib [19].…”

Absence of gene mutations in KIT-positive carcinoma showing thymus-like elements of the thyroid

“…KIT overexpression with low mutation frequency in thymic squamous cell carcinoma (SCC) was previously reported [6][7][8]. However, KIT expression and mutations have not been systematically clarified in a large series of CASTLE.…”

Promising efficacy of sorafenib in a relapsed thymic carcinoma with C-KIT exon 11 deletion mutation

“…This distinctive feature discriminate TC from thymoma. Activating KIT gene mutations are rare in thymic carcinoma [4,5]. Also this is a well known treatment target of the gastrointestinal stromal tumors (GIST) with thyrosine kinase inhibitors imatinib, sunitinib and sorafenib.…”

“…C-KIT expression and the presence of mutated KIT may thus provide important information regarding molecular targeted treatments. Although frequency and type of KIT mutations have not been described in TC, Tsuchida et al found C-KIT positivity at 100 percent of TC cases but no KIT mutation [4]. Yoh et al studied KIT mutation on TC and thymoma patients and missense mutations in exon 11 were found in 1 of 11.…”