FIGURE 2.

Forest plot and Kaplan–Meier analysis of overall survival by the PLN. (A) After adjusting for confounding factors (age, diabetes, betel nut chewing, differentiation, pT stage, and lymphovascular invasion), extranodal extension (ENE), and lower‐neck involvement were independent predictors of overall survival (OS), while laterality marginally approached significant. (B) After adjusting for the continuous number of PLNs and the same confounding factors, ENE, lower neck involvement, and laterality were not independent predictors of OS, but in each multivariate analysis, the number of PLNs was the independent predictor of OS. (C–H) A significant difference was observed between the patients with no nodal disease versus nodal disease, yet no significant difference was observed between the patients with one PLN versus those with two PLNs. Thus, we combined patients with one or two PLNs as one group. CI, confidence interval; HR, hazard ratio; OS, overall survival; PLN, positive lymph node; SEER, Surveillance, Epidemiology, and End Results Program.