Risk factors of lymph node metastasis in the splenic hilum of gastric cancer patients: a meta-analysis

BACKGROUND: The issue of whether or not splenic hilum lymph nodes (SHLN) should be excised in radical gastrectomy with D2 lymph node dissection remains controversial. In this study, we identified the clinicopathological features in patients with gastric cancer that could serve as predictive risk factors of SHLN metastasis. METHODS: We searched Medline, Embase, PubMed, and Web of Science databases from inception to May 2020 and consulted the related references. Overall, 15 articles evaluating a total of 4377 patients were included for study. The odds ratios (OR) of each risk factor and corresponding 95% confidence intervals (CI) were determined using the Revman 5.3 software. RESULTS: Our meta-analysis revealed tumor size greater than 5 cm (p < 0.01), tumor localization in the greater curvature (p < 0.01), diffuse type (Lauren’s classification) (p < 0.01), Borrmann types 3–4 (p < 0.01), poor differentiation and undifferentiation (p < 0.01), depth of invasion T3–T4 (p < 0.01), number of lymph node metastases N2–N3 (p < 0.01), distant metastasis M1 (p < 0.01), TNM stages 3–4 (p < 0.01), vascular invasion (p = 0.01), and lymphatic invasion (p < 0.01) as potential risk factors of SHLN metastasis. Moreover, positivity of Nos. 1, 2, 3, 4sa, 4sb, 4d, 6, 7, 9, 11, and 16 lymph nodes for metastasis was strongly associated with SHLN metastasis. CONCLUSIONS: Tumor size, tumor location, Lauren’s diffuse type, Borrmann type, degree of differentiation, T stage, N stage, M stage, TNM stage, vascular invasion, lymphatic infiltration, and other positive lymph nodes are risk factors for SHLN metastasis.