Primary and non-primary parotid malignancies: comparison of treatment modalities and outcomes

Our aim was to report our experience in the management of malignant primary and non-primary parotid neoplasms and to compare the clinical presentations, the treatment modalities and the outcomes in these two groups. We performed a retrospective review of the clinical and surgical data contained in patient files. Between January 1995 and December 2004, 60 patients with malignant parotid tumors were admitted to our department. Two groups were isolated: a group of 42 patients with primary parotid malignancies (group 1) and a group of 18 patients with non-primary parotid malignancies (intra-parotid metastasis and parotid lymphoma), (group 2). We compared the preoperative data, the surgical procedures performed total parotidectomy (TP) versus superficial parotidectomy (SP), the need for sacrificing the facial nerve and postoperative facial nerve function in the two groups. Actuarial survival rates were calculated using the Kaplan-Meier method in combination with the Log Rank test for comparison of the results in the two groups. Preoperative clinical facial nerve impairment was significantly more frequent in group 1 (33%) as compared to group 2 (6%) (P = 0.023). A SP was performed in 15 patients in group 2 while a TP was performed in 37 patients in group 1. The facial nerve was completely or partially sacrificed in 17 cases in group 1 and in only one case in group 2 (P = 0.03). One month after surgery, 18 patients in group 1 had persistent facial nerve dysfunction compared to only one patient in group 2 (P = 0.004). In group 1, the overall 1, 3 and 5-year survival rates were, respectively, 94, 76 and 69%. In group 2, the respective survival rates were 84, 62 and 40% (P = 0.4). This study outlines the differences in clinical presentation, surgical management and outcomes in the two main groups of malignant parotid tumors. The prognosis of facial nerve function was better in non-primary parotid malignancies. SP was the standard surgical option in group 2 patients while a TP was performed in the majority of the patients in group 1. Except when melanoma or lymphoma were present (which require specific treatment), adjuvant radiotherapy had the same indications in both groups when the tumors were high-grade, AJCC stages III and IV or when they had positive margins or lymph node and facial nerve involvement.