8th edition TNM esophageal cancer staging

TT1aInvasion of lamina propria or muscular mucosa

T1bInvasion of submucosa

T2Invasion of muscularis propria

T3Invasion of adventitia

T4aResectable tumor invading pleura, pericardium or diaphragm

T4bUnresectable tumor invading aorta, airway, vertebrae etc
NN0No lymph nodes 

N1One to two regional lymph nodes 

N2Three to six regional lymph nodes

N3Seven or more regional lymph nodes 
MM0No distant metastasis

M1Distant metastasis
Define unresectable?
  • Tumor contact more than 90 degrees
  • Loss of periaortic fat
  • Nodular soft tissue extension into major airways