High incidence of lymph node metastasis in major salivary gland cancer

OBJECTIVE: To analyze the incidence and risk factors for clinically apparent and occult lymph node metastases in patients with major salivary gland cancers. DESIGN: Cohort of patients with a median follow-up of 46 months (range, 1-174 months). SETTING: University-based referral center. PATIENTS: A total of 160 consecutive patients with complete clinical and pathologic data. INTERVENTION: Neck dissection was performed in all cases. Patients were treated with surgery alone (55%); surgery and radiation therapy (43%); or a combination of surgery, radiation, and chemotherapy (2%). MAIN OUTCOME MEASURE: Incidence of apparent and occult lymph node metastases. Univariate and multivariate analyses were used to evaluate the significance of clinical and pathologic data. RESULTS: Histologically confirmed positive neck was found in 53% of all cases. Histologic diagnosis was significantly related to the incidence of lymph node metastasis: 89% (16/18) for undifferentiated carcinomas. However, so-called low-risk tumors had incidence rates of 22% to 47%. Twenty-one patients (13%) presented with clinically apparent cervical lymph node metastasis. Of the 139 patients with clinical N0 neck, 45% had occult neck metastasis. Neck metastasis was found in 29% (10/34) of T1, 54% (38/70) of T2, 65% (20/31) of T3, and 54% (16/25) of T4 tumors. Assessment of survival according to nodal status revealed significant correlations for overall (P<.001) and disease-free survival (P<.001). CONCLUSIONS: We found a high incidence of lymph node metastasis from major salivary gland cancers. Neck dissections should be considered as an integral part of the surgical approach in patients with major salivary gland cancer, especially if no postoperative radiation therapy is planned.