Management of clinically negative neck in salivary gland cancers – elective neck dissection, irradiation, or surveillance?

Aim of the study
To retrospectively assess treatment outcomes among patients treated for salivary gland cancers at our institution to determine which of the three most common treatment approaches – elective neck dissection (END), elective neck irradiation (ENI), or observation – provide the best results.

Material and methods
A total of 122 patients were identified who had undergone primary surgery for SGC followed by END, ENI, or observation. The patients were classified into three groups according to the treatment approach used to manage the neck: END, ENI, or observation. The main outcome measures were disease-free survival (DFS) and overall survival (OS). We also sought to identify the risk factors potentially associated with neck metastasis and treatment failure.

Results
106 patients met all inclusion criteria. Of these 106 patients, 27 (25.7%) underwent END, 17 (16.0%) underwent ENI, and 62 (58.5%) observation. There were no statistically significant differences between the three groups in any of the following variables: advanced age (> 70); presence of locally advanced disease (T3 or T4); perineural invasion; lymphovascular invasion; and primary tumour location. Treatment failure was higher (non-significantly) in the END group (25.9%) vs. the observation (21.0%) and ENI (11.8%) groups. No differences (Kaplan-Meir curves) were observed among the three groups in terms of DFS or OS.

Conclusions
Our results show that elective neck dissection does not appear to provide any benefit to patients treated for malignant salivary gland cancer. Importantly, these findings contradict most of the currently available research. However, due to methodological differences among the available studies, our findings cannot be compared directly to other studies.