Patterns of lymph node spread and its influence on outcome in resectable parotid cancer.

Aim: To assess the metastatic topography of intraparotideal and neck lymph nodes in parotid cancer and its influence on tumour recurrence and survival.

Methods: The lymph node spread of 142 patients with primary parotid carcinoma treated from 1986 to 2006 was analysed. Disease-free survival (DFS) and overall survival (OS) were calculated. The role of the metastatic pattern as prognostic factors were univariately and multivariately analysed.

Results: A lateral, total or radical parotidectomy was performed in 19, 80 and 43 patients, respectively. A radical/radical-modified or selective neck dissection was performed in 68 and 74 patients, respectively. Eighty-seven neck dissection specimens were negative (pN0). Twelve patients had intraparotideal and cervical lymph node involvement (pPar+/pN+). In 24 patients only intraparotideal metastases were detected (pPar+/pN0). 19 patients only had cervical nodal involvement (pPar-/pN+). Twenty-five patients had occult locoregional lymph metastases (cN0/pN+). The median follow-up was 24.4 months. The disease-free survival rate was 81% at 5 years, and 62% at 10 years. By univariate analysis, R+ (p=0.001), pT (p=0.019), lymphangiosis carcinomatosa (p=0.019), pN+ (p=0.042), and extracapsular spread (p=0.046) were prognostic for disease-free survival. Multivariate analysis revealed R+ as independent risk factor (p=0.046). In pN+ patients, involvement of parotid lymph nodes (p=0.013), nodes in neck level I (p<0.0001) and IV (p=0.005) were univariate risk factors. Multivariate analysis showed lymph node metastases in level I as independent risk factor (p=0.022).

Conclusion: Total parotidectomy and radical-modified neck dissection is recommended as surgical treatment of parotid cancer and should be analysed in a prospective trial.