Surgical Treatment in Very Advanced (T4b) Adenoid Cystic Carcinoma of the Head and Neck

Abstract

Objective: To compare treatment outcomes for T4b head and neck adenoid cystic carcinoma (ACC).

Study design: Historical cohort study.

Setting: National Cancer Database (NCDB).

Methods: Identified all T4b ACC of head and neck origin diagnosed 2004 to 2019 in the NCDB. Demographics, clinical characteristics, treatment details, and survival were analyzed. Treatment outcomes were analyzed using univariable and multivariable Cox regression.

Results: We identified 606 cases of T4b ACC. Less than half (284, 47.0%) underwent curative-intent treatment. Among these, most were treated with primary surgery: surgery + radiotherapy (RT) (122, 43.0%) or surgery + chemoradiotherapy (CRT) (42, 14.8%). The positive margin rate was 78.7%, and 90-day postoperative mortality was zero. Nonsurgical patients were treated with definitive RT (60, 21.1%) or definitive CRT (60, 21.1%). The median follow-up was 51.5 months. Overall survival was 77.8% at 3 years. Three-year survival was higher for patients treated with surgery compared to those treated nonsurgically (84% vs 70%; p = .005). Surgical treatment remained associated with higher survival on multivariable analysis (hazard ratio [HR]: 0.47, p = .005). This effect was most pronounced for oral cavity tumors (HR: 0.17, p = .01). Among matched cohorts of surgically treated patients, there was no difference in 3-year survival between clinical T4a and T4b tumors (83.3% vs 83.0%, p = .99).

Conclusion: Long-term survival for T4b ACC of the head and neck could be expected. Primary surgical treatments can be performed safely and are associated with longer survival. A carefully selected subset of patients with very advanced ACC might benefit from the consideration of surgical treatments.

Keywords: adenoid cystic carcinoma; advanced; stage T4b; surgery; survival.