TNM

Stage

T

T1a

Tumor invades lamina propria or muscularis mucosae

T1b

Tumor invades submucosa

T2

Tumor invades muscularis propria

T3

Tumor penetrates subserosal connective tissue without invasion of visceral peritoneum or adjacent structures

T4a

Tumor invades serosa (visceral peritoneum)

T4b

Tumor invades adjacent structures

N

N0

No regional lymph node metastasis

N1

Metastasis in 1 - 2 regional lymph nodes

N2

Metastasis in 3 - 6 regional lymph nodes

N3

Metastasis in seven or more regional lymph nodes

M

M0

Distant metastasis absent

M1

Distant metastasis present