Long term oncological outcome of patients with grossly early gastric cancer-mimicking advanced gastric cancer

Background: The survival of grossly early gastric cancer-mimicking advanced gastric cancer (EGC-mimicking AGC) patients had not been investigated. We evaluated the prognosis of patients who were diagnosed as early gastric cancer before surgery and advanced gastric cancer after surgery. Methods: This retrospective study reviewed 3592 gastric cancer patients who had radical surgery from January 2007 to February 2015. We used a 1:2 propensity score matching method for the analysis. The matching factors were age, sex, body mass index and the depth of cancer invasion. The 5-year overall survival (OS) and disease-free survival (DFS) of the two study groups were analyzed. Results: The 475 grossly EGC-mimicking AGC patients were matched to 910 Borrmann type advanced gastric cancer (AGC) patients. The 5-year OS and DFS of the EGC-mimicking AGC patients were significantly higher than the Borrmann type AGC patients, (89.2% versus 83.4%, p = 0.025; 93.0% versus 85.6%, p < 0.001, respectively). The proportion of patients with lymph node (LN) metastasis was 45.5% in the EGC-mimicking AGC group and 57.1% in the Borrmann type AGC patients (p < 0.001). The ratio of metastatic LNs of N1 and N2 station was 5.2% and 3.1%, respectively, in EGC-mimicking AGC patients; this was lower than in Borrmann type AGC patients (N1: 8.9%, p < 0.001; N2: 3.7%, p = 0.308). Conclusions: Patients with grossly EGC-mimicking AGC had better prognosis than patients with the Borrmann type AGC due to fewer LN metastases. This suggests that limited LN dissection of EGC-mimicking AGC patients may be feasible.