Patterns of nodal involvement for clinically N0 salivary gland carcinoma: refining the role of elective neck irradiation.

Background: The purpose of this study was to analyze the pattern of occult cervical lymph node metastasis among patients with clinically N0 salivary gland carcinoma.

Methods: One hundred nineteen patients underwent primary surgery and ipsilateral neck dissection for clinically N0 carcinomas of the major and minor salivary glands. Eighty patients (67%) had parotid tumors. Distribution of T classification was: T1 (18%), T2 (28%), T3 (23%), and T4 (32%).

Results: Twenty-five patients (21%) had pathological cervical disease. The incidence was highest among patients with adenocarcinoma (35%) and high-grade mucoepidermoid carcinoma (35%). The most common site of cervical lymph node metastasis was level II (71%), followed by level III (15%), and level IB (8%). On multivariate analysis, histological subtype was independently predictive of occult pathological lymph node metastasis (p < .001).

Conclusion: The likelihood of occult cervical lymph node metastasis for patients with salivary gland carcinoma is driven predominantly by histological subtype. Implications for elective neck irradiation are discussed.