Clinical Relevance of Splenic Hilar Lymph Node Dissection for Proximal Gastric Cancer: A Propensity Score-Matching Case-Control Study.

BACKGROUND: The application of splenic hilar lymph node (no. 10 LN) dissection (no. 10 LND) for proximal gastric cancer (PGC) remains controversial. This study aimed to investigate the clinical relevance of no. 10 LND from the perspective of long-term survival. METHODS: The main study population included 995 previously untreated patients who underwent laparoscopic radical total gastrectomy between January 2008 and December 2014. Of these 995 patients, 564 underwent no. 10 LND (no. 10D+ group) and the remaining 431 patients did not (no. 10D- group). Propensity score-matching was applied to reduce the effects of confounding factors. The study end points were overall survival (OS) and disease-free survival (DFS). Additionally, 39 patients who received neoadjuvant chemotherapy during the same period also were included as a separate population for analysis. RESULTS: The metastasis rate for no. 10 LN was 10.5 % (59/564). No significant differences were observed in intra- and postoperative complications nor in mortality between the no. 10D+ and no. 10D- groups (all P > 0.05). After 1:1 matching, the two groups were comparable in clinicopathologic characteristics. The no. 10D+ group had significantly better survival than the no. 10D- group (5-year OS: 63.3 % vs 52.2 %, P = 0.003; 5-year DFS: 60.4 % vs 48.1 %, P = 0.013). For the patients who received neoadjuvant chemotherapy, the 5-year OS rates in the no. 10D+ and no. 10D- groups were respectively 50.6 % and 31.3 % (P = 0.150) and the 5-year DFS rates were respectively 51.5 % and 31.3 % (P = 0.123). CONCLUSIONS: Patients with untreated PGC may achieve the benefit of long-term survival from no. 10 LND. For patients with PGC who undergo neoadjuvant chemotherapy, no. 10 LND may not bring survival benefits. However, further validation with a large-sample study is needed.