Genomic Alterations Landscape in Adenoid Cystic Carcinoma of Head and Neck

Abstract

Introduction: Adenoid cystic carcinoma (ACC) accounts for 1% of all head and neck cancers and 10% to 22% of all malignant tumors of the salivary glands. ACC is associated with MYB- nuclear factor I/B-type (NFIB) gene fusion in about 50% of the cases. The genetic alteration (GA) landscape of ACC of head and neck region in this aspect has not been much studied, mainly due to small cohorts. We aim to describe the GA landscape of MYB-NFIB gene fusions, copy number alterations, and mutations of the related gene MYBL1 in human ACC by studying its association with regard to demographics and histopathological parameters. Materials and Methods: Using the GA data of ACC from a peer-reviewed web portal, we studied the presence of MYB-NFIB gene fusion with respect to age and gender distribution, site involved (major/minor salivary gland, lacrimal gland, cancer metastasis, others), histopathological diagnosis, perineural invasion (PNI), and the overall number of mutations. Descriptive statistics and Chi square test were performed. Data were entered and analyzed using SPSS version 23. The mutation counts between the type of gene fusions involved and the gender of patients was studied using analysis of variance tests. Results: Of the 214 reported ACC cases, 65 (30%) cases had MYB-NFIB fusion alone, 15 (7%) other had rare fusions, and 12 (6%) other had GAs. Perineural invasion was found to be associated with MYB gene fusion cases with or without copy number alterations (P = 0.022). The number of mutations were significantly associated with the gender of patient (P = 0.003) and NFIB gene fusions (P = 0.001). The other factors had no statistical significance. Conclusion: MYB-NFIB gene fusion and associated GA correlates with perineural involvement in ACC.