Influence of clinical prognostic factors in neck metastasis from malignant parotid tumors

Abstract

Objectives: Analyze the factors influencing lymph nodes metastasis in parotid malignant epithelial tumors. Methods: We retrospectively reviewed the files of 150 patients treated in our institution and by the authors, from 1974 to 1998. Twenty-three patients were excluded of this study because of nonsurgical treatment. The remaining 126 patients were treated with surgery and 75 patients had postoperative radiotherapy. Thirty-four patients were treated with parotidectomy plus neck dissection. The mean age was 49-years-old. According the UICC/1997 TNM Classification, we classified 49 patients as Stage I, 27 as Stage II, 22 as Stage III, and 28 as Stage IV. The influence of those factors on the presence of neck metastasis was analyzed using the chi-square method and multivariate analysis. Results: Forty patients had mucoepidermoid carcinoma, 18 patients had adenocarcinoma NOS, 18 patients had acinic cell carcinoma, 15 patients had adenoid cystic carcinoma, 11 patients had malignant mixed tumor, 11 patients had salivary duct carcinoma, 3 patients had basal cell adenocarcinoma, 3 patients had epithelial-myoepitelial carcinoma, 2 patients had malignant myoepithelioma, 2 patients had anaplastic carcinoma, 1 patient had primary squamous cell carcinoma, 1 patient had terminal duct adenocarcinoma, and 1 patient had papillary cystadenocarcinoma. Twenty-four patients had recurrences, 17 local recurrences, 4 patients had neck recurrences, and 3 locoregional recurrences. Seventeen patients had distant metastasis. The presence of neck metastasis was influenced by 4 factors in univariate analysis, age ( P 0.05), tumor classification ( P 0001), grade ( P 03), and histology ( P 003), and in multivariate analysis, Grade ( P 01) and tumor classification ( P 0001). Conclusions: The tumor classification and grade are an important factor to predict neck metastasis.