TNM cancer staging has provided a common language that permits description of the anatomic extent of a cancer. TNM staging aids treatment planning, prognostication, treatment evaluation, communication and exchange of information.

Recent TNM classification includes anatomic and non-anatomic cancer characteristics such as histological grade and location. Japanese classification of esophageal and gastric cancer uses the same TNM classification, but provides additional anatomical description of the primary tumors and metastases and treatment guidelines based on their great experience. Their detailed description of cancers is an essential tool to optimize treatment taking into account the evolution of rigid and flexible endoscopy techniques.