Table 1. AJCC TNM staging definitions (8^th Edition).

Stage	Description
T
T0	No evidence of primary tumor
T1	Maximum tumor diameter ≤2 cm
T2	Maximum tumor diameter >2 and ≤4 cm
T3	Maximum tumor diameter >4 cm
T4	Tumor involves the celiac axis, SMA, and/or CHA
N
N0	No regional lymph node metastases
N1	Metastasis in 1–3 regional lymph nodes
N2	Metastasis in ≥4 regional lymph nodes
M
M0	No distant metastases
M1	Distant metastasis