Role of radiotherapy in adenoid cystic carcinoma of the head and neck

This study retrospectively reviewed 183 cases of adenoid cystic carcinoma treated over 40 years. The local recurrence free survival rate was 68.2 per cent at five years and 40.8 per cent at 10 years. At 10 years, local recurrence free survival was significantly worse following radiotherapy alone (0 per cent), compared with surgery alone (41.8 per cent, p = 0.004) or combined with post-operative radiotherapy (43.5 per cent, p = 0.001). Neither tumour stage three or four, perineural invasion, solid subtype nor involved margins predicted local recurrence. Treatment with radiotherapy alone resulted in worse survival than surgery alone (p = 0.002) or combined with post-operative radiotherapy (p = 0.001). Survival rates following local recurrence (n = 34) were higher following surgery (p = 0.006) but not significantly improved following radiotherapy (p = 0.139). Chemotherapy for distant metastases did not prolong survival (p = 0.747) but did result in improved eating and aesthetics scores, while decreasing overall physical health. These results indicate that surgery is preferable for primary and recurrent adenoid cystic carcinoma of the head and neck. The incidence of local recurrence following surgery and postoperative radiotherapy was similar to surgery alone cases although the latter had less adverse prognostic features. Contemporary chemotherapy may benefit quality of life but not survival in patients with distant metastases due to adenoid cystic carcinoma of the head and neck.