Impact of lymph node sampling on survival in cN0 major salivary gland adenoid cystic carcinoma

Background The role of elective neck dissection in the management of major salivary gland adenoid cystic carcinoma is unclear. Methods Data were retrospectively extracted from the National Cancer Center Database. The study cohort included 1504 patients with adenoid cystic carcinoma of major salivary glands with clinical N0 necks who were treated with surgery between 2004 and 2014. The cohort was divided into four groups based on number of lymph nodes (LNs) examined on pathology: 0, 1-8, 9-17, and >= 18 LNs. Results The rate of occult nodal metastasis was 9.0%. Number of LNs removed was not associated with survival (Reference, 0 LNs; HR = 0.98, 95% CI 0.73-1.32 for 1-8 LNs; HR = 1.22, 95% CI 0.80-1.88 for 9-17 LNs; HR = 0.94, 95% CI 0.61-1.46 for >= 18 LNs) after adjusting for important covariates. Conclusions LN sampling is not associated with survival in cN0 major salivary gland ACC.