Outcomes and Prognostic Variables in Adenoid Cystic Carcinoma of the Head and Neck: A Recent Experience

Purpose

To analyze the recent experience of patients with adenoid cystic carcinoma treated with radiation therapy at Memorial Sloan-Kettering Cancer Center.

Methods and Materials

From 1990 to 2004, a total of 59 patients with a diagnosis of primary adenoid cystic carcinoma of the head and neck received radiation therapy at our institution. The subsite distribution was oral cavity, 28% (n = 17); paranasal sinuses, 22% (n = 13); parotid, 14% (n = 8); submandibular, 14% (n = 8); oropharynx, 10% (n = 6); sublingual, 3% (n = 2); nasopharynx, 3% (n = 2); and other, 5% (n = 3). T Stage distribution was T1, 34% (n = 20); T2, 19% (n = 11); T3, 14% (n = 8); and T4, 34% (n = 20). Twenty-nine percent of patients (n = 17) were treated with intensity-modulated radiation therapy; 25% (n =15), with three-dimensional conformal therapy, and the remainder, with conventional techniques. Ninety percent (n = 53) of patients received treatment including the base of skull.

Results

Median follow-up for surviving patients was 5.9 years. Five-year and 10-year rates of local control and distant metastases–free survival were 91%/81% and 81%/49%, respectively. Five-year and 10-year rates of disease-free and overall survival were 76%/40% and 87%/65%, respectively. On univariate analysis, stage T4 (p = 0.004) and gross/clinical nerve involvement (p = 0.002) were associated with decreased progression free survival, whereas stage T4 and lymph node involvement were associated with decreased overall survival (p = 0.046 and p < 0.001, respectively).

Conclusions

Radiation therapy in combination with surgery produces excellent rates of local control, although distant metastases account for a high proportion of failures. Routine treatment to the base of skull reduces the significance of histologic perineural invasion, but major nerve involvement remains an adverse prognostic factor.

Adenoid cystic, Salivary gland, Head and neck, Perineural invasion, T stage