Adenoid cystic carcinoma of the maxillary antrum.

Purpose: To investigate characteristic clinical features and outcome for patients with adenoid cystic carcinoma (ACC) of the maxillary antrum.
Patients and Methods: Twenty-two patients with ACC of the maxillary antrum were initially treated with surgery alone (3 patients), radiation alone (9 patients), or a combination of surgery and radiation (10 patients). Salvage treatment for initial failure was individualized. Patterns of failure, survival, and prognostic factors were retrospectively analyzed.
Results: The most frequent site of failure was local recurrence at the primary site (72.7%). All patients treated with either surgery alone or radiation alone experienced one or more local recurrences, whereas patients who received planned combined surgery and radiation had a much lower local recurrence rate (40%). Neck node failure (4.6%) was an uncommon event, whereas distant metastases were clinically documented in seven patients (32%). Most of the treatment failures appeared within 5 years, but treatment failures after 5 years were not uncommon. The overall survival and disease-free survival rates at 10 years were 37.6% and 13.6%, respectively. Clinicopathological factors, such as location of primary tumor, tumor stage, and histological grade were of no value in predicting a favorable survival. The significant prognostic factors influencing 10-year survival were the pathological finding of perineural invasion and the initial mode of treatment.
Conclusion: ACC of the maxillary antrum represented a unique natural history characterized by a more aggressive tumor behavior and an unfavorable prognosis. Combined surgery and radiotherapy is recommended for optimal local control and survival.