Comparison of the eighth version of the American Joint Committee on Cancer manual to the seventh version for colorectal cancer: A retrospective review of our data

Table 1 Comparison of the tumor-node-metastasis stages between the 7^th edition and the 8^th edition

7th edition	8th edition
Tx: Primary tumor cannot be assessed	Tx: Primary tumor cannot be assessed
T0: No evidence of primary tumor	T0: No evidence of primary tumor
Tis: Carcinoma in situ, limited to intraepithelial or invasive lamina propria	Tis: Carcinoma in situ, limited to intraepithelial or invasive lamina propria
T1: Tumor invading submucosa	T1: Tumor invading submucosa
T2: Tumor invading the muscularis propria	T2: Tumor invading the muscularis propria
T3: Tumor penetrating the muscularis propria and arriving at colorectal fat tissue	T3: Tumor penetrating the muscularis propria and arriving at colorectal fat tissue
T4: Tumor directly invading other organs or structures	T4: Tumor directly invading other organs or structures
T4a: Tumor penetrating visceral peritoneum	T4a: Tumor penetrating visceral peritoneum
T4b: Tumor directly invading or adhering to other organs or structures	T4b: Tumor directly invading or adhering to other organs or structures
Nx: Regional lymph nodes cannot be assessed	Nx: Regional lymph nodes cannot be assessed
N0: No lymph node metastasis and no tumor deposits (TD)	N0: No lymph node metastasis and no TD
N1: 1-3 lymph nodes metastases	N1: 1-3 lymph nodes metastases
N1a: 1 lymph node metastases	N1a: 1 lymph node metastases
N1b: 2-3 lymph nodes metastases	N1b: 2-3 lymph nodes metastases
N1c: Although there was no regional lymph node metastasis, TDs were submucosal, mesangial, or peritoneum-covered para-colorectal tissue.	N1c: Although there was no regional lymph node metastasis, TDs were submucosal, mesangial or peritoneum-covered para-colorectal tissue.
N2: More than or equal to 4 lymph node metastases	N2: More than or equal to 4 lymph node metastases
N2a: 4-6 regional lymph node metastases	N2a: 4-6 regional lymph node metastases
N2b: More than or equal to 7 lymph node metastases	N2b: More than or equal to 7 lymph node metastases
M1: There is distant lymph node metastasis	M1: There is distant lymph node metastasis
M1a: Metastasis is limited to one organ or site (e.g., liver, lung, ovary, and extra-regional lymph node metastases)	M1a: Metastasis is limited to one organ or site (e.g., liver, lung, ovary, and extra-regional lymph node metastases)
M1b: Transfer more than one organ or site, or to the peritoneum1	M1b: Transfer more than one organ or site1
	M1c: Peritoneal metastases with or without metastasis of other organs1

¹Differences between the two versions.