Background and Objectives: Adenoid cystic carcinoma (ACC) is a unique tumor characterized by frequent and delayed distant metastasis (DM) with uncommon regional lymph node metastasis. We evaluated the factors affecting DM of ACC and survival after appearance of DM.
Materials and Methods: Medical records, radiographs and pathologic slides were reviewed for 94 patients from 1979 through 2001.
Results: DM of ACC occurred in 46 patients, and developed more frequently in patients with tumors of the solid histologic subtype than in patients with tubular or cribriform subtypes. DM occurred less frequently in the sinonasal tract, and development of DM was not affected by tumor stage. Disease-specific 5- and 10-year survival rates were 88% and 72% for patients without DM, respectively and 76% and 48% for those with DM(p=0.02). Regarding the site of DM and its impact on outcomes, 30 patients had lung metastasis alone, 5 patients bone metastasis alone and 6 patients developed both lung and bone metastasis. Median survivals after appearance of DM among patients with isolated lung metastases and those with bone metastases with or without lung involvement were 54 and 21 months, respectively (p=0.04).
Conclusions: Development of DM in ACC is predicted by solid histologic subtype, and major salivary gland or oral/pharyngeal rather than sinonasal primary site. Those patients with bone involvement with our without lung metastases had worse outcomes than those with pulmonary metastasis only.
|