Concurrent chemoradiotherapy for locally advanced unresectable adenoid cystic carcinoma of head and neck: experience from a single institute

Purpose: To analyze the outcome of locally advanced unresectable adenoid cystic carcinoma (ACC) of head and neck treated with radical concurrent chemoradiotherapy (CRT) at a single tertiary care centre.

Methods: Between 2011 and 2018, 23 patients with locally advanced unresectable ACC of head and neck treated with non-surgical radical treatment with concurrent chemoradiotherapy were evaluated for outcome and toxicity. All but one patient received cisplatin-based concurrent chemotherapy and 74% of patients were treated with intensity-modulated radiotherapy.

Results: Median follow-up was 53 months (range 3-115 months). Following treatment, 11 patients achieved complete response (47.8%) and of the 12 patients with residual disease, 7 patients additionally had disease stabilization without local progression. Overall 15 patients had disease progression. Median time to progression was 28 months (range 6-67 months). The 3-year and 5-year overall survival, local progression-free survival (LPFS) and distant progression-free survival (DPFS) were 78%, 79.7%, 67.4% and 63%, 50.9%, 48.6%, respectively. Acute grade 3 mucositis was observed in three patients, and one patient additionally developed grade 4 neutropenia with subsequent complete recovery. No grade 3 or higher late toxicity was observed.

Conclusion: Radical concurrent chemoradiotherapy is a promising treatment option in locally advanced unresectable ACC with acceptable toxicity.