Figure 3.

A, B, Graphs showing the interaction between tumor size and type of surgery as a function of adjusted hazard ratio of mortality from a multivariate Cox proportional hazards model including an interaction term between tumor size and type of surgery. These graphs show the overall group of patients with squamous cell carcinoma (A) and the subgroup with pathologic N0 disease as well (B). The x-axis shows the tumor size in millimeters, whereas the y-axis demonstrates the adjusted hazard ratio from the Cox model. The survival curves for patients who underwent lobectomy or segmentectomy are depicted and modelled using restricted cubic splines. The shaded areas represent the bounds of the 95% CI.