Abstract
Background
Since the definition of early gastric cancer (EGC) was first proposed in 1971, the treatment of gastric cancer with or without lymph node metastasis (LNM) has changed a lot. The present study aims to identify risk factors for LNM and prognosis, and to further evaluate the indications for adjuvant chemotherapy (AC) in T1N + M0 gastric cancer.
Methods
A total of 1291 patients with T1N + M0 gastric cancer were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate analyses were performed to identify risk factors for LNM. The effect of LNM on overall survival (OS) and cancer-specific survival (CSS) was compared with patients grouped into T1N0-1 and T1N2-3, as the indications for AC.
Results
The rate of LNM was 19.52%. Multivariate analyses showed age, tumor size, invasion depth, and type of differentiation and retrieved LNs were associated with LNM (p < 0.05). Cox multivariate analyses indicated age, sex, tumor size, N stage were independent predictors of OS and CSS (p < 0.05), while race was indicator for OS (HR 0.866; 95%CI 0.750–0.999, p = 0.049), but not for CSS (HR 0.878; 95% CI 0.723–1.065, p = 0.187). In addition, survival analysis showed the proportion of patients in N+/N0 was better distributed than N0-1/N2-3b. There were statistically significant differences in OS and CSS between patients with and without chemotherapy in pT1N1M0 patients (p༜0.05).
Conclusions
Both tumor size and invasion depth are associated with LNM and prognosis. LNM is an important predictor of prognosis. pT1N + M0 may be appropriate candidates for AC. Currently, the treatment and prognosis of T1N0M0/T1N + M0 are completely different. An updated definition of EGC, taking into tumor size, invasion depth and LNM, may be more appropriate in an era of precision medicine.