Presentation and outcomes of patients with clinically T1-2, N0 parotid mucoepidermoid carcinoma: The roles of elective neck dissection and adjuvant radiotherapy

Abstract

Objectives: Examine the role of elective neck dissection (END) and adjuvant radiotherapy (RT) in early-stage clinically N0 parotid mucoepidermoid carcinoma (MEC).

Methods: The study is a retrospective analysis of the National Cancer Database, 2004-2016. The study population included adult patients with MEC who underwent parotidectomy.

Results: A total of 1233 patients were included. Histopathology demonstrated well, moderately, and poorly differentiated MEC 47.12%, 39.98%, and 12.90% of the time, respectively. END was performed in 78.67% of patients, resulting in nodal upstaging in 4.43% and identification of extracapsular extension (ECE) in 0.72%. RT was utilized in 67.33% of patients with advanced pathological features. Neither END nor RT improved overall survival separately (p < 0.05) or combined (adjusted HR: 1.19, 95%CI: 0.52, 2.70, p = 0.68).

Conclusion: This study provides an epidemiological perspective regarding patients with clinically T1-2, N0 MEC. There was no observed survival advantage with END and RT.

Keywords: epidemiology; facial nerve; mucoepidermoid carcinoma; neck dissection; parotidectomy; radiotherapy; survival.

FIGURE 1

Probability of advanced pathological features in patients with clinically T1‐2, N0 parotid mucoepidermoid carcinoma who underwent surgical resection [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 2

Prevalence of elective neck dissection and positive lymph node(s) in relation to the study period in patients with clinically T1‐2, N0 parotid mucoepidermoid carcinoma who underwent surgical resection [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 3

Prevalence of adjuvant radiotherapy utilization in relation to the study period and the presence of advanced pathological features (poorly differentiated, T3‐4a, lymphovascular invasion, extracapsular extension, positive surgical margins) in patients with clinically T1‐2, N0 parotid mucoepidermoid carcinoma who underwent surgical resection [Color figure can be viewed at wileyonlinelibrary.com]

FIGURE 4

Overall survival of patients presenting with clinically T1‐2, N0 parotid mucoepidermoid carcinoma based on (A) elective neck dissection outcome, (B) absence or presence of one or more advanced pathological features (poorly differentiated, T3‐4a, positive lymph node(s), positive surgical margins, lymphovascular invasion, extracapsular extension), (C) whether elective neck dissection and adjuvant radiotherapy were utilized in patients with no advanced pathological features, (D) whether elective neck dissection and adjuvant radiotherapy were utilized in patent with one or more advanced pathological features [Color figure can be viewed at wileyonlinelibrary.com]