Prognostic Factors Affecting Survival in Patients With Head and Neck Adenoid Cystic Carcinoma: A Single-Institution Experience

Background Head and neck adenoid cystic carcinoma (AdCC) is an uncommon salivary malignancy characterised by indolent growth but aggressive local behaviour, frequent perineural invasion, and late distant metastasis. The prognostic value of lymph node involvement, perineural invasion, bone invasion, and tumour grade remains uncertain. This study evaluated survival outcomes following surgery for AdCC and assessed the association of key pathological factors with disease control. Methods A retrospective review of 89 patients with AdCC treated surgically between 1990 and 2020 was performed. Clinicopathological variables were analysed for their impact on overall survival (OS) and disease-free survival (DFS). Survival probabilities were calculated using the Kaplan-Meier method. Results Of the 89 patients, 53 (60%) were female, with a mean age of 54.3 ± 15.9 years. Most tumours originated in major salivary glands. Neck dissection was performed in 29 patients, and lymph node metastasis was identified in eight (28%). Perineural invasion was present in 54 (60%) cases. Thirty-one patients (35%) developed recurrence: nine (29%) local, four (12%) regional, and 18 (58%) distant failures. Regional nodal metastasis and high-grade tumours were significantly associated with poorer OS and DFS. Conclusion In this cohort, lymph node involvement and tumour grade independently predicted reduced OS and DFS. One-third of patients experienced recurrence, predominantly at distant sites, reinforcing the need for long-term surveillance and improved systemic strategies.