Treatment and clinicopathologic predictors for adenoid cystic carcinomas of the head and neck.

Purpose: To retrospectively evaluate the management and clinicopathologic predictors of outcome of adenoid cystic carcinoma (ACC) patients treated and followed at our Department.

Methods: Data on 41 patients treated between 2000 and 2006 at the University of Istanbul, Institute of Oncology, were reviewed. Factors affecting recurrence, distant metastasis and survival were evaluated.

Results: There were 22 (53.6%) major salivary and 19 (46.3%) minor salivary gland tumors. Eighteen patients (43.9%) had solid histologic type tumor. Twenty-one (51%) patients had perineural invasion and 28 (68.2%) high grade tumors. Sixteen (39%) patients had stage I disease, 12 (29.1%) stage II and 13 (31.5%) stage III. Thirty-two patients (78.4%) had radical and 9 (21.9%) partial resection. Thirty-one patients (75.6%) received adjuvant postoperative radiotherapy (RT). Eight patients (19.5%) suffered locoregional relapse and 9 (21%) distant metastases. Two patients (4.8%) died from ACC and 7 (17%) from other causes. The median follow-up was 48 months (range 24-60). Disease free survival (DFS) at 2 and 3 years were 78% and 58%, respectively. Overall survival (OS) at 2 years and 3 years were 87% and 80%, respectively. Median time to locoregional relapse and distant metastasis was 28 and 32 months, respectively. Seven of 9 patients with distant metastasis had solid tumor subtype. Distant metastasis occurred more frequently in patients with tumors of major salivary glands (66%). Sites of distant metastasis were lung alone (n=5), bone alone (n=2) and 2 patients had both lung and bone metastasis. There was no statistically significant relationship between clinical T stage and solid histology with locoregional relapse (p <0.05). Surgical resection type and perineural invasion were significant prognostic factors for locoregional relapse (p=0.03). T stage (p=0.001), grade (p=0.02) and solid histology (p=0.003) were prognostic factors associated with DFS. Prognostic factors associated with OS were grade (p= 0.001), clinical T stage (p=0.02), solid histology (p=0.01), radical excision (p=0.04) and perineural invasion (p=0.001).

Conclusion: ACC is a neoplasm in which early diagnosis is important because it is a slow-growing tumor producing diffuse invasion. Distant metastasis and locoregional relapse can be predicted by solid histologic subtype, high grade, type of surgery, perineural invasion and tumor stage. The most frequent sites of metastasis are lung and bone.