Leiomyosarcoma of the head and neck: a population-based analysis.

Objectives: To describe the characteristics of head and neck leiomyosarcoma and to identify factors associated with survival.

Design: Retrospective population-based study.

Patients: The 17-registry Surveillance, Epidemiology, and End Results database was used to identify 578 patients with leiomyosarcoma of the head and neck.

Interventions: Surgery and primary and adjuvant radiotherapy.

Main Outcome Measures: Patient demographics and tumor characteristics were examined. Treatment modalities were compared, and survival was assessed using the log-rank test.

Results: The mean age at diagnosis was 64 years. Most tumors were smaller than 5 cm in greatest dimension (87%) and high grade (44% were moderately differentiated and 39% were poorly differentiated). The primary tumor demonstrated deep extension in 39% of cases, and 2% had lymph node metastases. The most common primary site was the skin and soft tissue of the head and neck (83%). Surgical treatment was provided to 89% of patients, 14% received adjuvant radiotherapy, and 4% received radiotherapy alone. The median observed survival was 84.7 months. The 5-year disease-specific survival rate was 87.6% in patients with well-differentiated tumors, 85.7% in patients with moderately differentiated tumors, and 52.7% in patients with poorly differentiated tumors (P < .001). Survival was better for patients who received surgery alone (median survival, 100.1 months [n = 413]) than for those who received radiotherapy alone (median survival, 16 months [n = 16]) or adjuvant radiotherapy (median survival, 64.2 months [n = 80]) (P < .001). The latter group was more likely to have poorly differentiated, large, locally invasive tumors.

Conclusions: Leiomyosarcoma typically presents in older patients; it is often poorly differentiated; and improved survival is associated with surgical treatment.