Patient selection
tumors, adenocarcinoma, cardia
TUMORS, GCA, ADENOCARCINOMA, TUMOR METASTASIS
The specific operational process for extracting information from the SEER database is outlined below: (1) Register for a personal account on the SEER database official website and install the SEER*Stat software; (2) Extract clinical data of patients based on the inclusion and exclusion criteria determined in this study; (3) Export the extracted data as a spreadsheet and proceed to the next step of organizing and analyzing the data.The data for patients with GCA between 2010 and 2015 were downloaded from the SEER*Stat 8.4.0 software using a private ID (13914‐Nov2021), based on the 2021 release of the SEER database. According to the SEER codes, patients with adenocarcinoma (ICD‐O‐3 codes: 8140–8145,8147, 8210, 8211, 8214, 8220, 8221, 8230, 8231, 8255, 8260–8263, 8310, 8480, 8481, 8490, 8510, 8560, 8562, 8570–8576) and tumors located in the cardia (site code: C16.0) were included. All patients underwent radical surgery (surgery encode 30–80); however, those with stage IV GCA were excluded due to the controversial nature of their operation. In addition, patients with missing information on relevant variables were excluded from this study. The detailed screening process and selection criteria are shown in Figure Flowchart for the selection of the patients.In addition to the above data, the data of patients with GCA after surgery at the First Affiliated Hospital of Zhengzhou University between 2012 and 2018 were collected for validation. Patients underwent thorough preoperative assessments, including physical exams, medical history recording, hematological testing, and imaging. Furthermore, tumor metastasis was evaluated using various imaging techniques. The study was approved by the hospital ethics committee, and patient records were kept confidential in accordance with ethical standards.