The 12th Edition of the Japanese Classification of Esophageal Cancer, published by the Japan Esophageal Society in 2022, provides a comprehensive guide for the clinical and pathological description of esophageal cancer. This article is the first half of the English edition, covering general rules, descriptions of primary tumors, lymph nodes, distant organ and lymph node metastasis, staging, and handling of resected specimens. The classification aims to standardize nomenclature and promote international use, emphasizing preoperative treatment and consistency with the TNM classification of the Union for International Cancer Control (UICC). Key topics include: 1. **Purpose and Object**: The classification refers to cancer originating in the esophagus, excluding metastatic cases. All primary malignant tumors of the esophagus should be described according to this classification. 2. **Description of Primary Tumor**: Details on tumor location, size, circumferential extent, macroscopic type, depth of invasion, lymphatic and venous invasion, and surgical findings. 3. **Description of Lymph Nodes**: Anatomical definitions and boundaries of lymph node stations, regional lymph nodes, and grading of lymph node metastasis. 4. **Distant Organ and Lymph Node Metastasis**: Criteria for distant organ and lymph node metastasis. 5. **Staging**: Staging of cervical and thoracic esophageal cancer, squamous cell carcinoma of the esophagogastric junction, and adenocarcinoma of the esophagogastric junction. 6. **Handling of Resected Specimens**: Guidelines for handling endoscopically and surgically resected specimens. The classification includes detailed descriptions of tumor types, invasion patterns, and diagnostic criteria, with a focus on improving accuracy and consistency in clinical practice.The 12th Edition of the Japanese Classification of Esophageal Cancer, published by the Japan Esophageal Society in 2022, provides a comprehensive guide for the clinical and pathological description of esophageal cancer. This article is the first half of the English edition, covering general rules, descriptions of primary tumors, lymph nodes, distant organ and lymph node metastasis, staging, and handling of resected specimens. The classification aims to standardize nomenclature and promote international use, emphasizing preoperative treatment and consistency with the TNM classification of the Union for International Cancer Control (UICC). Key topics include: 1. **Purpose and Object**: The classification refers to cancer originating in the esophagus, excluding metastatic cases. All primary malignant tumors of the esophagus should be described according to this classification. 2. **Description of Primary Tumor**: Details on tumor location, size, circumferential extent, macroscopic type, depth of invasion, lymphatic and venous invasion, and surgical findings. 3. **Description of Lymph Nodes**: Anatomical definitions and boundaries of lymph node stations, regional lymph nodes, and grading of lymph node metastasis. 4. **Distant Organ and Lymph Node Metastasis**: Criteria for distant organ and lymph node metastasis. 5. **Staging**: Staging of cervical and thoracic esophageal cancer, squamous cell carcinoma of the esophagogastric junction, and adenocarcinoma of the esophagogastric junction. 6. **Handling of Resected Specimens**: Guidelines for handling endoscopically and surgically resected specimens. The classification includes detailed descriptions of tumor types, invasion patterns, and diagnostic criteria, with a focus on improving accuracy and consistency in clinical practice.