Prognostic factors of adenoid cystic carcinoma of head and neck.

5584 Background: Adenoid cystic carcinoma is a rare malignancy, accounting for about 1% of head and neck cancer. We assessed clinical characteristics and prognostic factors affecting clinical outcomes in patients with ACC of head and neck. Methods: From February 1991 to July 2009, a total of 88 patients with ACC of head and neck who underwent curative intent surgery with or without adjuvant radiotherapy (RT) at Asan Medical Center, Seoul, Korea were analyzed retrospectively. Results: R0 resection was done in 29 (33.0%). Sixty-four (72.7%) received postoperative RT. Median dose of RT was 61.1 Gy (range, 18.0-70.0). Thirty five patients recurred, 18 of whom developed distant metastasis. Most common metastasis site was lung (72.2%). Disease free survival (DFS) rate at 3-years and 5-years was 66.3% and 48.9%, respectively. Overall survival (OS) at 5-years and 10-years was 89.7% and 70.3%, respectively. On multivariate analyses, ACC of salivary gland showed significantly lower recurrence rate than that of other sites (p=0.028). Postoperative RT at 33 fraction or more had a significant impact on recurrence rate (p=0.027) and DFS (p=0.001). Young (under 40) and old (60 or older) age, histologic feature of solid form, stage III or IV were significantly associated with shorter DFS (p=0.029, p=0.003, and p=0.010, respectively). The age of 60 or older significantly affected OS adversely (p=0.034 and p=0.034, respectively). Conclusions: Age, tumor location, histologic feature, stage, adequate fraction of postoperative RT were significant prognostic factors on ACC of head and neck. Multivariate analysis of clinical parameters. Clinical parameters P value Odds ratio/hazard ratio (95% CI) Recurrence Tumor location (salivary glands) 0.028 0.307 (0.10.7-0.883) Postoperative RT (>33Fx) 0.027 0.308 (0.109-0.872) Disease-free survival Age (<40 or > 60 y) 0.029 2.408 (1.096-5.290) Histologic feature, solid form 0.003 8.784 (2.130-36.223) Stage III or IV 0.010 2.845 (1.288-6.285) Postoperative RT (>33Fx) 0.001 0.229 (0.095-0.553) Tumor location (nasal cavity, paranasal sinus or pharynx) 0.071 2.195 (0.936-5.145) Overall survival Age>60 y 0.034 2.760 (1.078-7.066)