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.