Nodal metastasis in major salivary gland cancer - Predictive factors and effects on survival

Objectives: To determine how regional nodal metastasis affects survival in patients with major salivary gland malignancy and to identify clinical predictors for nodal disease. Methods: Major salivary gland cancer cases with nodal sampling were identified from the Surveillance, Epidemiology, and End Results cancer database for 1988 through 1998. Kaplan-Meier survival analysis was conducted to compare patients with and without histopathologic evidence of nodal disease. Multivariate logistic regression analysis was used to determine the influence of clinical predictors on the presence of regional nodal disease. Results: A total of 1268 patients with major salivary gland malignancy and regional node sampling were identified. Mean age at diagnosis was 58.3 years, with a male-female ratio of 1:4. Mean tumor size was 3.0 cm. Overall mean survival time was 83 months (95% confidence interval, 80-87 months). Patients with no evidence of nodal cancer had significantly improved survival over patients with any pathologically positive nodes (mean survival time, 100 months vs 59 months, respectively; P<.001). Patient age, tumor histopathologic type, facial nerve involvement, extraglandular involvement, tumor grade, and tumor size were significant clinical predictors of nodal disease. Facial nerve involvement, tumor grade, and squamous cell carcinoma subtype exhibited the highest increased odds ratios for nodal metastasis. Conclusions: Nodal disease significantly decreases survival in patients with major salivary gland malignancy. Tumor histopathologic type, facial nerve involvement, extraglandular tumor extension, and tumor grade are the most important predictors of nodal disease.