BackgroundAs a common malignancy, gastric cancer (GC) remains an important threat to human’s health. The incidence of synchronous multiple gastric cancer (SMGC) has increased obviously with technical advances of endoscopic and pathological examinations. Several studies have investigated the relationship between SMGC and solitary gastric cancer (SGC). However, little is known about the relationship between early and advanced SMGCs, and the independent risk factors of lymph node metastasis and prognosis in SMGC patients remain unclear.MethodsWe retrospectively collected 57 patients diagnosed as SMGC and underwent radical gastrectomies from December 2011 to September 2019. Epidemiological data and clinicopathological characteristics of all patients were recorded. Postoperative follow-up was performed by telephone or outpatient service. Chi-squared test or Fisher’s exact test was adopted in analysis of categorical data. Continuous data were analyzed by using unpaired t test. Univariate and multivariate analyses were performed to investigate the independent risk factors of lymph node metastasis and tumor recurrence of SMGC.ResultsThere were 45 males and 12 females. The average age was 62.1 years old. There were 20 patients with early SMGC and 37 patients with advanced SMGC. Most of patients (91.2%) had two malignant lesions. Tumor recurrence occurred in 8 patients, among which 7 patients died from recurrence. The rates of total gastrectomy, tumor size ≥ 2 cm, poorly differentiated type, lymph node metastasis, ulcer and nerve invasion, and preoperative CEA level were significantly higher in advanced SMGC patients compared to those with early SMGC. Lymphovascular cancer plug and preoperative CA125 were the independent risk factors of lymph node metastasis in patients with SMGC. Lymph node metastasis, nerve invasion, and preoperative AFP might be the risk factors of tumor recurrence of SMGC, but need further validation.ConclusionsIn patients with SMGC, the presence of tumor size ≥ 2 cm, poorly differentiated type, lymph node metastasis, ulcer, nerve invasion, and relatively high preoperative CEA level might indicate the advanced SMGC. More attention should be paid to lymph node metastasis in SMGC patients with lymphovascular cancer plug and high preoperative CA125. Lymph node metastasis, nerve invasion, and preoperative AFP might be associated with recurrence of SMGC, needing further validation.