Effect of smoking status and programmed death-ligand 1 expression on the microenvironment and malignant transformation of oral leukoplakia: A retrospective cohort study
Fig 2
Nelson–Aalen plots of cumulative malignant transformation rates according to smoking status and PD-L1 expression.
Smoking patients with positive PD-L1 expression are represented by the solid black line and smoking patients with negative PD-L1 expression by the dashed black line. Non-smoking patients with positive PD-L1 expression are represented by the solid gray line and non-smoking patients with negative PD-L1 expression by the dashed gray line. Non-smoking patients with positive PD-L1 expression had a higher cumulative malignant transformation rate than those in the other three groups.