Can the analysis of positive sentinel lymph nodes in patients with early oral cancer provide a basis for formulating a risk model? A systematic review and meta-analysis of the literature.

Sentinel lymph nodes are often the first nodes to be involved in early oral cancer. The aim of this review was to assess the relation of clinicopathological factors in patients with positive sentinel lymph nodes. We propose formulating a risk prediction model that could elucidate the individual risk of nodal metastases and prognosis in early oral squamous cell carcinoma (SCC). A systematic review was undertaken in accordance with the PRISMA protocol. Study quality was assessed using STROBE, and bias was assessed using the ROBINS-I tool. Meta-analysis was carried out using the Mantel-Haenszel method for calculating the weighted pooled odds ratio under the fixed effects model. Thirty studies published between 2004 and 2023 were included. Pooled sentinel lymph node positivity from 27 studies averaged 26.7%. On meta-analysis 26% of T1N0 and 35% of T2N0 patients were sentinel-node positive. On pooled meta-analysis, there was an increased odds ratio for sentinel node positivity that was statistically significant for pT2 status, a non-cohesive tumour front, moderate differentiation, and the tongue subsite. We believe that these findings not only add to the current evidence but will also contribute to a future risk model for management of the neck in patients with early oral SCC.