Mutation analysis of the EGFR pathway genes, and , in salivary gland adenoid cystic carcinoma.

Adenoid cystic carcinoma (AdCC), one of the most common salivary gland carcinomas, usually has a fatal outcome. Epidermal growth factor receptor (EGFR) pathway gene mutations are important in predicting a patient's prognosis and estimating the efficacy of molecular therapy targeting the EGFR pathway. In this study of salivary gland AdCC (SAdCC), we looked for gene mutations in family ( and ), and , using a highly sensitive single-base extension multiplex assay, SNaPshot. Out of 70 cases, EGFR pathway missense mutations were found in 13 (18.6%): mutations in 10 (14.3%), in one (1.4%), and in 5 (7.1%). None of the cases showed an deletion by direct sequencing. Concurrent gene mutations were found in three cases (4.3%). EGFR pathway mutations were significantly associated with a shorter disease-free ( = 0.011) and overall survival ( = 0.049) and mutations were as well; ( = 0.010) and ( = 0.024), respectively. The gene fusion status as determined by a FISH assay had no significant association with mutations of the genes involved in the EGFR pathway. In conclusion, EGFR pathway mutations, especially mutations, may be frequent in SAdCC, and associated with a poor prognosis for the patient.