Study population
gastric cancer, stomach cancer, gastric adenocarcinoma
METASTASIS, TUMOURS, STOMACH CANCER, GASTRIC ADENOCARCINOMA, GIST, NEUROENDOCRINE TUMOUR, PATHOLOGY, GASTRIC CANCER
In this study, the clinical features of 123,964 patients with stomach cancer were downloaded between 2000 and 2018 from the SEER database using SEER*Stat software (v8.3.6).The eligibility criteria were as follows: (1) At or over the age of 65; (2) All patients had been pathologically confirmed to have gastric adenocarcinoma by preoperative gastroscopy biopsy or postoperative pathology; (3) All patients underwent radical (R0) surgical treatment consisting of gastrectomy and lymphadenectomy; (4) Histologically proven locally advanced gastric cancer patients (T1-2N + M0 or T3-4NanyM0); and (5) All the patients had complete follow-up data. The exclusion criteria were as follows: (1) Patients under the age of 65 or early gastric cancer (EGC); (2) Patients with multiple tumours, or distant metastasis; (3) Patients with confirmed pathology diagnosis of nonadenocarcinoma, GIST or a neuroendocrine tumour; (4) Patients who did not undergo gastrectomy or underwent partial gastrectomy; (5) All-cause mortality within 30 days of surgery; and (6) Patients with incomplete clinical data (medical records or follow-up data).The data screening process is shown in the flow diagram (Fig. Flow chart of patient selection