Figure 1

Tumor classification. We categorized tumors near the EGJ into four types according to its location and main histological type. Categorization criteria were: (i) squamous-cell carcinoma with epicenter in the esophagus within 5 cm from EGJ (type E (SQ)); (ii) adenocarcinoma with epicenter in the esophagus within 5 cm from EGJ (type E (AD)); (iii) any histological tumor with epicenter in the stomach within 5 cm from EGJ, with EGJ invasion (type Ge); (iv) any histological tumor with epicenter in the stomach within 5 cm from EGJ, without EGJ invasion (type G). Type E (SQ), E (AD) and Ge tumors were categorized as esophageal cancer; type G tumor was categorized as gastric cancer by the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) Cancer Staging Manual. Siewert type I and III tumors were categorized as type E (AD) and Ge tumors, and Siewert type II tumor was categorized as type E (AD) or Ge tumor in this study.