Staging and prognosis of esophageal cancer

Staging and prognosis of esophageal cancer
For staging (classifying the extent and severity of a malignant tumor disease) using the TNM system of the AJCC (American Joint Comitee of --T (tumor size), N (lymph nodes) and M (distant metastasis) Cancer):

Primary tumor (T)

TX     Unable to assess the primary tumor.
T0     No evidence of primary tumor.
Tis     High-grade dysplasia.
T1     Tumor invades lamina propria, muscularis mucosa or submucosa ..
T1a     Tumor invades lamina propria or muscularis mucosa ..
T1b     The tumor invades the submucosa.
T2     Tumor invades musculari own.
T3     Tumor invades adventitia ..
T4     The tumor invades adjacent structures ..
T4a     Resectable tumor invades the pleura, pericardium, or diaphragm.
T4b     Unresectable tumor invading other adjacent structures, such as aorta, vertebral body, trachea, etc. ..
Regional lymph nodes (N)

NX     You can not assess the regional lymph nodes.
N0     No regional lymph node metastasis.
N1     Metastasis in 1-2 regional lymph nodes.
N2     Metastasis 3-6 regional lymph nodes or submucosa ..
N3     Metastases in regional lymph nodes ≥ 7.
Distant metastasis (M)

M0     No distant metastases.
M1     There is distant metastasis.
Prognosis of esophageal cancer

Depending on the staging we can see the chances of survival with esophageal cancer at 5 years.

Stadium    T    N    M    Survival at 5 years
0     Tis     N0     M0     > 95%
I     T1     N0     M0     50-80%
IIa     T2-3     N1     M0     30-40%
IIb     T1-2     N1     M0     10-30%
III     T3     N0-1     M0     10-15%
      T4     N0-1     M0     10-15%
IV     T1-4     N0-1     M1     1-5%
Factors associated with a worse prognosis of esophageal cancer are loss of weight upon the length of the tumor and the presence of micrometastases in regional lymph nodes.