Figure 3 : Multivariate Cox proportional hazard model was used to examine the association between
recurrence/progression and potential risk factor WHO grade.

Statistical adjustments were made for age and sex. Hazard ratio with 95% confidence interval was reported. There was
a strong prognostic effect of WHO grade on recurrency/progression (p=0.0094). The hazard rate of WHO grade II-III was
12.88 times (95% CI 1.87 – 88.76) that of WHO grade I.