Definition of Tumor Risks in Colon Cancer^*

Primary tumor (T)
T1	Tumor invades submucosa
T2	Tumor invades muscularis propria
T3	Tumor invades through the muscularis propria into pericolorectal tissues
T4	Tumor invades the visceral peritoneum or invades or is adherent to other organs or structures
Regional lymph nodes (N)
N1	Metastasis in 1-3 regional lymph nodes
N2	Metastasis in 4 or more regional lymph nodes

^*refer to https://cancerstaging.org/references-tools/quickreferences/Documents/ColonMedium.pdf and https://emedicine.medscape.com/article/2006674-overview