Risk factors for local recurrence of adenoid cystic carcinoma: The role of postoperative radiation therapy

Purpose: Postoperative radiation therapy is often advocated in the treatment of patients with adenoid cystic carcinoma (ACC) of the head and neck. A retrospective analysis was performed to determine prognostic factors for local recurrence after surgery and to examine the role of postoperative radiation therapy. Materials and Methods: A retrospective analysis of 58 patients undergoing surgery for ACC of the head and neck at the University of Pittsburgh Medical Center from 1974 to 1994 was performed. Patients were followed up for a minimum of 24 months for the development of recurrent disease. The association of recurrence was correlated with clinical factors (age, sex, site, and stage); postoperative treatment (radiation therapy v no radiation); and pathologic variables (grade, margins of resection, and perineural invasion), and appropriate statistical analysis was performed. Results: Recurrent disease developed in 59% of patients, despite the addition of postoperative radiation therapy in 83% of patients. Tumor site was the single most important factor for the development of locally recurrent disease and was correlated with primary tumor stage and resection margins. Local recurrence rates were decreased (P = .07) in patients with negative surgical margins who were irradiated. Conclusions: Larger perspective randomized trials are necessary to evaluate the efficacy of postoperative radiation, and new treatments need to be investigated to improve local control rates for ACC of the head and neck.