T1 - invades lamina propria, muscular mucosae, or submucosa
T1a - invades lamina propria or muscular mucosae
T1b - invades submucosa
T2 - invades mucularis propria
T3 - invades adventitia
T4 - invades adjacent structures
T4a - resectable tumor invading pleura, pericardium, or diaphragm
T4b - unresectable tumor invading other adjacent structures, such as aorta, vertebral body, trachea, etc.
N-stage: Regional lymph nodes "extend from periesophageal cervical nodes to celiac nodes."
Includes: levels 1 (low cervical, supraclavicular), 2 (upper paratracheal), 3P (retrotracheal), 4 (lower paratracheal), 5 (subaortic), 6 (ascending aorta), 7 (subcarinal), 8 (paraesophageal), 9 (pulm ligament), 10 (hilar), 15 (diaphragmatic), 16 (paracardial), 17 (L gastric), 20 (celiac).* [levels according to Lymph node mapping system for Esophageal Cancer. From Casson (PMID 7979715); see lymph node map Korst 1998(PMID 9535455)]
*See erratum in 7th reprint of AJCC Staging Manual
N0 - no lymph node metastases
N1 - metastasis in 1-2 regional nodes
N2 - metastasis in 3-6 regional nodes
N3 - metastasis in 7 or more nodes
M-stage:
M0 - no distant metastasis
M1 - distant metastasis
Tumor location
Location is defined by the position of the upper/proximal edge of the tumor -- see Overview#Anatomy
Overall stage:
Squamous
Adenocarcinoma
IA - Any location: T1 N0 and Grade 1 (or Grade unknown)
IB - Any location: T1 N0 and Grade 2-3 IB - Lower tumor: T2-3 N0 and Grade 1
IIA - Upper or middle tumor: T2-3 N0 and Grade 1 (or GX) IIA - Lower tumor/X: T2-3 N0 and Grade 2-3
IIB - Upper or middle tumor: T2-3 N0 and Grade 2-3 IIB - Any location: T1-2 N1
The stages below are the same for squamous + adeno:
IIIA - Any location: T1-2 N2, T3 N1, T4a N0
IIIB - Any location: T3 N2
IIIC - Any location: T4a N1-2, T4b, N3
IV - M1
IA - T1 N0 and Grade 1-2 (or Grade unknown)
IB - T1 N0 and Grade 3, T2 N0 and Grade 1-2 (or GX)
IIA - T2 N0 and Grade 3
IIB - T3 N0, T1-2 N1
The stages below are the same for squamous + adeno:
IIIA - T1-2 N2, T3 N1, T4a N0
IIIB - T3 N2
IIIC - T4a N1-2, T4b, N3
IV - M1
Changes from 6th edition
Subdivided T1 into T1a and T1b
Subdivided T4 into T4a and T4b
Changed N-stage from N0-1 to N0-3 based on # of nodes
Revised definition of regional lymph nodes
Overall stage: I subdivided into IA/IB, III into IIIA/B/C
Overall stage now incorporates tumor grade and tumor location (upper,middle,lower) and histology
M1 no longer subdivided into M1a and M1b (M1a was redefined as N+ regional nodes)
Note: This staging includes tumors of the esophagogastric junction and proximal 5 cm of the stomach (see details at Overview). This division was clarified in the 7th edition AJCC Staging Manual. There was also specification of tumor location as cervical, upper thoracic, middle thoracic, and lower.
