Distant metastasis and survival of adenoid cystic carcinoma after definitive treatment

ObjectiveAdenoid cystic carcinoma (ACC) is an aggressive tumor and characterized by late development of distant metastases (DM). The aim of study was to analyze the clinicopathological predictors of DM in ACC and to determine survival after the development of DM.MethodsThirty patients with ACC treated by surgery and/or radiotherapy were included. The impact of clinicopathological factors on DM was assessed. Factors included primary site, T stage, histological growth pattern, surgical margin, perineural invasion (PNI), postoperative radiotherapy (PORT) and local recurrence. The median follow-up was 62 months (range, 3–267 months).ResultsTwenty-four patients have relapsed local and/or distant metastases. The most common pattern of tumor relapse was DM, which developed in 17 patients. The 5-year, 10-year, and 15-year disease-free survival rate was 46%, 19%, and 15%, respectively. The positive surgical margin was significantly associated with DM rate. Neither primary site, T stage, histologic growth pattern, PNI, PORT nor local recurrence influenced on DM rates. The median survival period after the detection of DM for lung metastasis alone or bone and others were 47 months and 19 months, respectively (P = 0.03).ConclusionsACC develops DM frequently even without locoregional recurrences. Only the status of surgical margins showed an association with the occurrence of DM. The survival of patients developing DM is significantly associated with the site of metastases and better in patients with lung compared to bone and other organs. A multimodality treatment approach including chemotherapy and molecular targets therapy is warranted to treat distant metastatic disease.