Occurrence of lymph node metastasis in early-stage parotid gland cancer

Abstract

Lymph node metastasis is one of the most important factors in therapy and prognosis for patients with parotid gland cancer. Nevertheless, the extent of the primary tumor resection and the necessity of a neck dissection still is a common issue. Since little is known about lymph node metastasis in early-stage parotid gland cancer, the purpose of the present study was to evaluate the occurrence of lymph node metastases in T1 and T2 carcinomas and its impact on local control and survival. We retrospectively analyzed 70 patients with early-stage (T1 and T2) primary parotid gland cancer. All patients were treated with parotidectomy and an ipsilateral neck dissection from 1987 to 2009. Clinicopathological and survival parameters were calculated. The median follow-up time was 51.7 months. A positive pathological lymph node stage (pN+) was found in 21.4% of patients with a significant correlation to the clinical lymph node stage (cN) (p = 0.061). There were no differences in the clinical and histopathological data between pN- and pN+ patients. In 73.3% of pN+ patients, the metastases were located intraparotideal. The incidence of occult metastases (pN+/cN-) was 17.2%. Of all patients with occult metastases, 30.0% had extraparotideal lymphatic spread. A positive lymph node stage significantly indicated a poorer 5-year overall as well as 5-year disease-free survival rate compared to pN- patients (p = 0.048; p = 0.011). We propose total parotidectomy in combination with at least a level II-III selective neck dissection in any case of early-stage parotid gland cancer.