Retropharyngeal lymph node metastasis in oral cancer. Systematic review and survival analysis

Abstract

Introduction: Metastasis to retropharyngeal lymph nodes (RPLN) from oral squamous cell carcinoma is rare and associated with poor outcomes. The poor prognosis of RPLN is multifactorial and includes the clinicopathological aggressiveness of the primary disease and the late presentation. The aim of this systematic review is to assess the evidence on RPLN in patients diagnosed with oral squamous cell carcinoma (OSCC), the quality of the diagnostic modalities and the available treatment options. We aimed to analyse the overall survival of these patients diagnosed with RPLN.

Methods: A systematic review was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. The initial literature search generated 289 articles. A total of 11 papers satisfied our criteria. Eight papers provided enough data to perform survival analysis and 3 papers compared the diagnostic modalities used in the detection of RPLN.

Results: A total of 73 OSCC patients diagnosed with RPLN metastasis were identified. The most common primary tumour subsites included the tongue (20), buccal mucosa (15) and gingiva (11). The cumulative 5-year OS rate was 17.8% while the 2-year overall survival was 35.9%.

Conclusion: The presence of nodal metastasis is an independent prognostic factor in head and neck cancer. In this study, RPLN metastasis had a poorer prognosis (5 years overall survival is 17.8%) when compared to the survival rate of oral cancer without RPLN metastasis (5 years overall survival is 40%). There was no statistically significant difference between the overall survival in primary RPLN metastasis and recurrent RPLN disease.

Keywords: imaging modalities; oral squamous cell carcinoma; retropharyngeal lymph nodes.