T1: tumor size ≤2 cm
T1a: ≤0.5 cm
T1b: >0.5 cm and <1
T1c: ≥1cm and ≤2 cm
T2: tumor size >2 cm and ≤4 cm
T3: Tumor size >4 cm
T4: celiac axis, SMA, or CHA involvement
N1: 1-3 regional nodes
N2:≥4 regional nodes