A Retrospective 8-Year Single Institutional Study in Germany Regarding Diagnosis, Treatment, and Outcome of Malignant Parotid Tumors

Abstract

This study sought to comprehensively evaluate the diagnosis, therapeutic interventions, and outcomes of individuals afflicted with malignant parotid tumors at a tertiary care otolaryngology department in Heilbronn, Germany, spanning the years 2010-2018. The primary objective was to juxtapose this dataset with findings from analogous single and multicenter investigations. We conducted a meticulous analysis of electronic medical records pertaining to 45 patients subjected to primary parotid cancer treatment. The male-to-female ratio was 3:2, with an average age of 61 years. Predominant histological types included mucoepidermoid and squamous cell carcinomas, with ultrasound emerging as the predominant diagnostic modality (97.8% sensitivity). Intraoperative frozen sections exhibited a high level of sensitivity. Notably, lymph node metastasis was prevalent in T3 tumors, frequently located intraparotid and at Neck level II. Solely one patient exhibited distant metastases (pulmonary). All patients underwent parotidectomy, and 29% necessitated a secondary procedure due to positive resection margins. Postoperative complications encompassed facial nerve palsy, seromas, and salivary fistulas. Adjuvant radiotherapy (38%) was recommended for high-grade tumors, T3/T4 stage, N+, perineural invasion (PNI), and positive or uncertain surgical margins. Neck dissection was executed in 67% of instances, with 20% revealing occult lymph node metastases. Recurrence manifested in 22% of patients, primarily as locoregional recurrence (80%) and distant metastases (20%). The 3-year recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) rates stood at 72.1%, 91.9%, and 87.5%, respectively. Noteworthy factors influencing RFS included preoperative facial palsy, T stage, resection margins, and PNI. In summary, the management of parotid cancer involving surgical interventions, neck dissection, and radiotherapy in high-risk patients yielded commendable outcomes with minimal complications, showcasing survival rates exceeding 70%. Timely diagnosis at an early stage is imperative for achieving tumor-free margins and enhancing survival rates. More assertive therapeutic strategies are advocated for cases presenting with preoperative facial nerve palsy and PNI.

Keywords: diagnosis; outcome; parotid cancer; parotidectomy; radiotherapy; survival rate; treatment; tumor.

Figure 1

Selection of the patients.

Figure 2

Kaplan–Meier curves of RFS, CSS and OS.

Figure 3

Kaplan–Meier curves on recurrence-free survival according to T stage (a) (p=0.0003), N stage (b) (p=0.195), clinical stage (c) (p=0.039), resection margins (d)(p=0.021), perineural invasion (e) (p=0.009), and preoperative facial palsy (f) (p < 0.0001).