Esophageal cancer: A Review of epidemiology, pathogenesis, staging workup and treatment modalities

Table 1 TNM system, specifically referring to depth of invasion in T staging

Category	Description
Tis	Carcinoma in situ
T1	Tumors invade lamina propria or submucosa
T2	Tumors invade muscularis propria
T3	Tumors invade adventitia
T4	Tumors invade adjacent structures
N0	No regional lymph node metastases
N1	Regional lymph node metastases
M0	No distant metastasis
M1a, M1b	Distant metastasis

Table 2 Aspect of staging is essential in determining stage-specific protocols for treatment

Stage	Tumor	Node	Metastasis	Therapeutic options
0	Tis	N0	M0	Local ablative therapy
I	T1	N0	M0	Surgery
IIA	T2	N0	M0	Surgery
	T3	N0	M0
IIB	T1	N1	M0	Neoadjuvant therapy with or without surgery
	T2	N1	M0
III	T3	N1	M0	Neoadjuvant therapy with or without surgery
	T4	Any N	M0
IVA	Any T	Any N	M1a	Chemotherapy or radiation therapy with or without surgery
IVB	Any T	Any N	M1b	Palliative treatment