Distant metastases of adenoid cystic carcinoma of the salivary glands and the value of diagnostic examinations during follow-up

Abstract

Background: Adenoid cystic carcinoma (ACC) accounts for approximately 10% of all neoplasms of the salivary glands. Late distant metastases and local recurrences are responsible for a rather low long-term survival rate.

Aim: To study the metastasizing pattern of ACC of the salivary glands in 51 patients.

Method: Fifty-one patients with an ACC in the intraoral/sublingual salivary glands (n = 30), parotid gland (n = 8), submandibular gland (n = 2), maxillary sinus (n = 6), and nasal cavity (n = 5) have been studied. The male-female ratio was 1:1, the mean age was 54.3 (range, 19-81) years. In 30 cases treatment consisted of surgery and radiotherapy. In 13 cases surgery alone was carried out. The average follow-up time was 117.8 (range, 1-171) months.

Results: In 28 cases (54.9%) distant metastases occurred, and in 3 patients (5.8%) regional lymph node metastases occurred. In 12 of the 28 patients with distant metastases (42.8%), only the lungs were involved, whereas in 5 of the 28 patients (17.8%), the distant metastases occurred in other organs (eg, bones and brain). In 11 of the 28 patients (39.2%) metastases were found both in the lungs and other organs. Twenty-four of the 51 patients (47.0%) died because of their tumor. The average time between the occurrence of lung metastases and death was 32.3 months and between the occurrence of metastases elsewhere and death 20.6 months.

Conclusion: Distant metastases of ACC of the salivary glands occur most often in the lungs. Although these lung metastases are the first to occur, these patients die later than patients with distant metastases in other organs. The value of annual chest films or other tests for the presence of distant metastases during follow-up after surgical removal of an ACC seems rather questionable.