The Clinical Significance and Risk Factors of Solitary Lymph Node Metastasis in Gastric Cancer

AIMS: To assess the clinical significance and risk factors of solitary lymph node metastasis (SLM) in gastric carcinoma and establish a more accurate method to evaluate the possibility of lymph node metastasis (LM). METHODS: A total of 385 patients with gastric carcinoma who underwent D2 lymphadenectomy at the Cancer Center of Sun Yat-Sen University were included in this research. Then we used a group of data from Sun Yat-sen University Gastrointestinal Hospital (SYSUGIH) to validate the accuracy of our developed method. The χ(2) test, Kaplan–Meier analysis, log-rank test, COX model, and discriminate analysis were used to analyze the data with SPSS13.0. RESULTS: We found that the LM number and pathological T staging were independent prognostic risk factors. CEA grading, LN status by CT, and T staging by CT were independent risk factors for LM in gastric carcinoma. In addition, we developed the equation Y = -5.0 + X (1) + 1.8X (3) + 0.7X (4) (X (1) = CEA grading, X (3) = LN status by CT, X (4) = T staging by CT) to evaluate the situation of LM. The data from SYSUGIH shows this equation has a better accuracy compared with CT. CONCLUSIONS: SLM is an independent risk factor in gastric cancer. And there was no survival difference between the skip metastasis group and the other SLM group (P = 0.659). It is inappropriate for the patient with SLM doing a standard D2 lymphadenectomy, due to the fact that LM rarely occurs in the splenic artery, splenic hilum. The risk factors for LM include CEA grading, LN status by CT, and T staging by CT. And we can use Y = -5.0 + X (1) + 1.8X (3) + 0.7X (4) (X (1), CEA grading, X (3) = LN status by CT, X (4) = T staging by CT, the critical value is 0.3) to estimate the possibility of LM, which has a better accuracy compared with CT.