Number of positive nodes - Current relevance in determining prognosis of oral cavity cancer after the recent AJCC staging update

Abstract

Introduction: Lymph node involvement and the number of positive nodes is a significant prognosticator in oral cavity cancers and current staging system does not incorporate it as an integral part.

Material and methods: This was a retrospective study of oral cavity cancer patients who were operated during the time period of 2009-2017. The data was collected and analysed to assess the impact of increase in the number of positive nodes on survival and its comparison of survival statistics to current AJCC staging.

Results: A total of 1431 patients were included in this study and 32.5% of these patients had a node positive disease. Nodal positivity was a significant prognosticator on multivariate analysis. Number of positive nodes was modelled with restricted cubic spline function and it showed progressive worsening of survival functions with increase in number. On Kaplan Meier analysis there was a better separation of curves when number of positive nodes was used and Akaike information criterion (AIC) showed that it was a better prognosticator than existing AJCC staging.

Conclusion: Number of positive nodes is a significant prognosticator of prognosis and hence should be considered in the AJCC staging system.

Keywords: Nodal disease; Number of positive nodes; Oral cavity cancer; Staging; Survival.