Primary tumor (T) |
TX | Primary tumor cannot be assessed |
T0 | No evidence of primary tumor |
Tis | Carcinoma in situ: intraepithelial or invasion of lamina propria* |
T1 | Tumor invades submucosa |
T2 | Tumor invades muscularis propria |
T3 | Tumor invades through the muscularis propria into pericolorectal tissues |
T4a | Tumor penetrates to the surface of the visceral peritoneum¶ |
T4b | Tumor directly invades or is adherent to other organs or structures¶Δ |
Regional lymph node (N)◊ |
NX | Regional lymph nodes cannot be assessed |
N0 | No regional lymph node metastasis |
N1 | Metastasis in one to three regional lymph nodes |
N1a | Metastasis in one regional lymph node |
N1b | Metastasis in two to three regional lymph nodes |
N1c | Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized pericolic or perirectal tissues without regional nodal metastasis |
N2 | Metastasis in four or more regional lymph nodes |
N2a | Metastasis in four to six regional lymph nodes |
N2b | Metastasis in seven or more regional lymph nodes |
Distant metastasis (M) |
M0 | No distant metastasis |
M1 | Distant metastasis |
M1a | Metastasis confined to one organ or site (eg, liver, lung, ovary, nonregional node) |
M1b | Metastases in more than one organ/site or the peritoneum |
Anatomic stage/prognostic groups§ |
Stage | T | N | M | Dukes¥ | MAC¥ |
0 | Tis | N0 | M0 | – | – |
I | T1 | N0 | M0 | A | A |
T2 | N0 | M0 | A | B1 |
IIA | T3 | N0 | M0 | B | B2 |
IIB | T4a | N0 | M0 | B | B2 |
IIC | T4b | N0 | M0 | B | B3 |
IIIA | T1 to T2 | N1/N1c | M0 | C | C1 |
T1 | N2a | M0 | C | C1 |
IIIB | T3 to T4a | N1/N1c | M0 | C | C2 |
T2 to T3 | N2a | M0 | C | C1/C2 |
T1 to T2 | N2b | M0 | C | C1 |
IIIC | T4a | N2a | M0 | C | C2 |
T3 to T4a | N2b | M0 | C | C2 |
T4b | N1 to N2 | M0 | C | C3 |
IVA | Any T | Any N | M1a | – | – |
IVB | Any T | Any N | M1b | – | – |