EGFR Expression and KRAS and BRAF Mutational Status in Intestinal-Type Sinonasal Adenocarcinoma

Abstract: Accumulation of molecular alterations, including EGFR overexpression and mutations in KRAS and BRAF, contribute to colorectal carcinogenesis. Since intestinal-type adenocarcinoma (ITAC) of the nasal cavity and paranasal sinus has morphologic and phenotypic features that are usually indistinguishable from colorectal cancer (CRC), it is likely that both tumor types share equivalent genetic alterations. Data from a series of 43 patients treated surgically for ITAC in Montpellier, France between November 1998 and December 2012 were collected. Tumors were characterized for mutations in KRAS and BRAF as well as EGFR overexpression. Kaplan-Meier survival curves were constructed using overall survival as the primary end points. Patient survival was analyzed using the hazards ratio. Twenty seven tumors (63%) showed EGFR positivity and 30% exhibited a high expression level (+2/+3). KRAS mutations were detected in 43% of cases. BRAF mutations were identified in 3.6% of specimens. Patients with age superior to 60 years, metastatic status, and KRAS mutations had significant overall survival values (p = 0.026, p = 0.001 and p = 0.03, respectively). Our results indicate that KRAS mutations and EGFR expression are frequent in ITAC and that KRAS mutations predict good patient prognosis in ITAC. Finally, EGFR directed molecular treatments could be investigated in a subset of patients affected by ITAC.