Significance of MYB and NTRK Expression in Head and Neck Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) is an aggressive neoplasm even though it has low-grade histological appearance and slow growth. The aim of this study was to identify the immunohistochemical and molecular characteristics of ACC, as well as their correlation with the clinical course of patients.

This is a retrospective multicenter analysis. We included 50 patients diagnosed with ACC in the head and neck between 2000 and 2021. The expression of MYB proto-oncogene transcription factor (MYB), neurotrophic tyrosine kinase receptor (NTRK), human epidermal receptor-2 (HER-2), and Ki-67 was examined through immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). We also performed a clinical follow-up of the patients.

The median age of the patients was 58.5 years; moreover, 54% of the patients were male. Compared with female patients, male patients were at a higher risk of both recurrence and death. No HER-2-positive cases were revealed. MYB expression was positive in 28 (56%) cases. However, MYB expression did not significantly affect survival. NTRK expression was positive in eight (16%) cases. NTRK-positive patients had worse overall survival (OS) than NTRK-negative patients (p=0.0246). Additionally, the percentage of NTRK-stained cells was negatively correlated with disease-free survival (p=0.0016) and OS (p=0.0027).

There was no correlation between MYB positivity and survival. Contrarily, NTRK-positive patients had worse survival, indicating that NTRK is a negative prognostic factor. Tropomyosin receptor kinase inhibitors can be used to treat these patients. Furthermore, MYB-targeted inhibitors are promising therapeutic agents.