Adenoid Cystic Carcinoma with Involvement of the Sinonasal Cavity

Background: Adenoid cystic carcinoma is the most common salivary gland malignant tumor. The highest frequency is in the oral cavity (palate followed by the tongue, buccal mucosa and lip). Sinonasal tumors often affect maxillary sinus and nasal cavity.

This type of tumor has a predisposition to perineural and bone invasion, which can lead to the involvement of noble structures such as: skull base, orbit, dura mater, carotid artery and cranial nerves.

The long-term survival in sinonasal malignancies is poor and treatment remains a challenge. The purpose of this study was to evaluate the prognostic factors, recurrence patterns, survival rates and therapeutic results in patients with sinonasal adenoid cystic carcinoma treated in a tertiary hospital.

Methods: A retrospective study was performed including patients diagnosed with adenoid cystic carcinoma between 2000 and 2018 with an epicenter in the nasal cavity or paranasal sinuses or tumor invasion at these regions. Patients enrolled in the study underwent at least one surgery in our institution.

The following parameters were analyzed in the medical records: demographic data, tumor topography, cranial base extension/invasion, TNM stage, type of surgery performed, surgical margins, histopathological invasion patterns, adjuvant therapy, and recurrences.

The results analyzed included disease-specific survival and disease-free survival. The Kaplan–Meier product-limit method was used to generate the curves describing the results. The statistical significance between the curves was tested by the log-rank test.

Results: We analyzed the medical records of 193 patients with Adenoid Cystic Carcinoma treated from 2000 to 2018. Among them, 44 fulfilled the inclusion criteria, of which 27 (61.4%) were women and 17 (38.6%) were men with a mean age of 52.83 years, ranging from 30 to 84 years. Thirty-one patients (70.4%) presented tumor located in the nasal cavity and paranasal sinuses. In 12 patients (27.3%) the tumor was originally in the palate and extended to the nasal cavity and 1 patient (2.3%) had tumor in lacrimal gland with extension to nasal cavity.

Surgeries performed were: endoscopic medial maxillectomy, total maxillectomy, craniofacial resection, maxillectomy infrastructure, orbital exenteration, endoscopic transpterygoid nasopharyngectomy and endoscopic transcribriform resection. Most patients (86.3%) received adjuvant radiotherapy. Fifty-nine percent of the patients underwent resection with clear margins, 27.3% with microscopically compromised margins and 13.6% with macroscopically compromised margins. The local recurrence rate and the distant metastases rate were both 47.7%. The disease-specific survival was 78.41% in 5 years and 46.2% in 10 years. The disease-free survival was 54.13% in 5 years and 13.92% in 10 years.

Conclusion: Adenoid cystic carcinoma has a pattern of local recurrence and late distant metastases. It presents insidious clinical behavior with tendency to decrease the survival rates after 10 years of disease. The standard treatment is surgical resection followed by adjuvant radiotherapy.