Tx: No clear evidence of primary cancer, e.g. cytological examination such as pulling screen found tumor cells, but failed to find tumor body.
T0: No evidence of primary tumor.
Tis: carcinoma in situ, also known as highly atypical hyperplasia. It refers to tumors confined within the epithelial layer and not invading out of the basement membrane.
T1: Tumor invades the epithelial layer, such as invading the lamina propria, mucosal muscle layer or submucosa.
T2: Tumor invades the muscularis propria and does not reach the outer membrane of the esophagus.
T3: Tumor invaded the adventitia.
T4: Tumor invaded the peripheral tissues of esophagus.
4a: Tumor invaded the pleura, pericardium or diaphragm, but could be surgically removed.
T4b: The tumor is not surgically resectable because it invades the trachea, aorta, myocardium or other important organs.
N stage
N0: No adjacent lymph node metastasis.
N1: 1 or 2 lymph node metastases in the adjacent lymph node group.
N2: 3-6 lymph node metastases in the adjacent lymph node group.
N3: More than 7 lymph node metastases in the adjacent lymph node group.
M stage
M0: The tumor has no distant organ and lymph node metastasis.
M1: Tumor has metastasized to distant lymph nodes and/or other organs.
G staging G refers to the pathological differentiation of tumor staging, which is optional in the 6th edition of AJCC tumor staging, but is accepted as one of the S staging in the 7th edition.
GX: histologically ungradable (same as G1 in S staging).
G1: highly differentiated carcinoma with well differentiated cells.
G2: moderately differentiated carcinoma with moderately differentiated cells.
G3: poorly differentiated hypodifferentiated carcinoma with poor cell differentiation
G4: undifferentiated carcinoma (S stage according to G3 squamous carcinoma).
Sometimes G3 and G4 may be mixed and can be registered as G3-4.
Tumor site The S staging of early squamous carcinoma takes into account the site of the tumor on the esophagus, which is divided into upper, middle and lower segments according to the upper edge of the tumor.
S staging S staging is a combination of T, N and M stages, and the seventh edition separates squamous esophageal cancer from adenocarcinoma.
Esophageal squamous carcinoma Its staging includes T, N, M, G stages and the site of tumor.
Stage 0: Tis, N0, M0, GX or G1, any site. It is the earliest stage of esophageal cancer, equivalent to carcinoma in situ, and the tumor is limited to the epithelial layer without any metastasis or dissemination.
Stage IA: T1, N0, M0, GX or G1, any site. Equivalent to stage T1 tumor. The tumor is confined to the mucosal layer, submucosa.
Stage IB: T1, N0, M0, G2 or G3, any site. One or all of the following two points are met.
The tumor is located in the innermost two layers of the esophagus (mucosal layer, submucosa), but the tumor cells are poorly differentiated.
T2 or T3, N0, M0, GX or G1, located in the lower segment. The tumor invades the muscular layer of the esophagus (T2) or even the outer membrane (T3), but the tumor is located in the lower segment of the esophagus and the cells are well differentiated.
Stage IIA: T2 or T3, N0, M0, GX or G1 in the upper or middle esophagus, or G2 or G3 in the lower esophagus.
Stage IIB: T2 or T3 (tumor located in one of the two outermost layers of the esophagus), N0, M0, G2 or G3 (poorly differentiated tumor cells), tumor located in the upper or middle esophagus; or: T1 or T2 (located in the inner two layers of the esophagus), N1 (1-2 lymph node metastases), M0, any G, any site.
Stage IIIA: T1 or T2 (tumor located in the inner layer of the esophagus), N2 (3-6 adjacent lymph node metastases), M0, any G; or: T3 (located in the outer layer of the esophageal wall), N1 (1-2 adjacent lymph node metastases), M0, any G; or: T4a (tumor invading resectable tissue around the esophagus), N0, M0, any G.
Stage IIIB: T3 (outer structures located in the esophageal wall), N2 (3-6 adjacent lymph node metastases), M0, any G, any site.
Stage IIIC: T4a (invasion of adjacent esophageal tissues but surgically resectable), N1 or N2 (6 or fewer adjacent lymph node metastases), M0, any G, any site; or: T4b (invasion of peripheral tissues not surgically resectable), any N, M0, any G, any site; or: any T, N3 (7 or more adjacent lymph node metastases), M0, any G, any site.
Stage IV: any T, any N, M1, any G, any site.
Esophageal adenocarcinoma Adenocarcinoma staging includes indicators of T, N, M, G staging.
Stage 0: Tis, N0, M0, GX or G1; equivalent to carcinoma in situ or highly atypical hyperplasia with tumor confined to the superficial layer of the esophageal wall.
Stage IA: T1, N0, M0, GX, G1 or G2; equivalent to stage T1, with tumor located only in one of the two innermost layers of the esophageal wall.
Stage IB: T1 (tumor located only in one of the two innermost layers of the esophageal wall), N0, M0, G3 (poorly differentiated tumor cells); or: T2 (tumor located in the outer layer of the esophageal wall), N0, M0, GX, G1 or G2
Stage IIA: T2 (tumor located in the outer layer of the esophagus), N0, M0, G3 (poorly differentiated cells).
Stage IIB: T3 (tumor located in the outer layer of the esophagus but not beyond), N0, M0,any G; or: T1 or T2 (tumor located in the inner lamina propria of the esophagus), N1 (1-2 adjacent lymph node metastases), M0,any G
Stage IIIA: T1 or T2 (tumor located in the inner layer of the esophagus), N2 (3-6 adjacent lymph node metastases), M0, any G; or: T3 (located in the outer layer of the esophageal wall), N1 (1-2 adjacent lymph node metastases), M0, any G; or: T4a (tumor invading resectable tissue around the esophagus), N0, M0, any G.
Stage IIIB: T3 (located in the outer layer of the esophageal wall), N2 (3-6 lymph node metastases), M0, any G.
Stage IIIC: T4a (tumor invades adjacent tissue), N1 or N2 (6 or fewer lymph node metastases), M0, any G; or: T4b (tumor invades adjacent tissue and cannot be surgically removed), any N, M0, any G; or: any T, N3 (7 or more adjacent lymph node metastases), M0, any G.
Stage IV: any T,any N, M1,any G.