Sorafenib efficacy in thymic carcinomas seems not to require c-KIT or PDGFR-alpha mutations.

PURPOSE

To retrospectively evaluate sorafenib activity and safety in patients with metastatic thymic carcinoma (TC) and to correlate outcome with c-KIT and PDGFR-alpha mutational status.

PATIENTS AND METHODS

Patients with metastatic thymic carcinoma treated with sorafenib after at least one prior line of chemotherapy were included. Objective response rate (ORR) and toxicity were evaluated. Analysis of c-KIT and PDGFR-alpha mutational status was performed retrospectively.

RESULTS

From October 2007 to August 2011, 5 patients with metastatic thymic carcinoma were evaluated. A median of 8 cycles of sorafenib (range=3-29) were administered. Two patients (40%) displayed a partial response (PR), two patients presented stable disease (SD), while one patient had progression. The median progression-free (PFS) and overall survival were 28 weeks and 92 weeks, respectively. At mutational analysis, only one patient with PR had c-KIT mutation in exon 17 and was successfully treated with sunitinib for 12 months after progression to sorafenib. No PDGFR-alpha mutations were found.

CONCLUSION

Sorafenib activity seems independent from the c-KIT and PDGFR-alpha mutational status. After progression, sequence treatment with a different tyrosine kinase inhibitor can be considered. These results are promising and need further confirmation on larger, possibly prospective, series of patients.