Lymph node ratio is a prognostic indicator for locally advanced gastric cancer after neoadjuvant immunochemotherapy

Objective The efficacy of lymph node ratio (LNR) as a prognostic indicator in locally advanced gastric cancer (LAGC) patients underwent radical resection after neoadjuvant immunochemotherapy (NICT) remains to be demonstrated. The objective of the current retrospective study is to investigate the relationship between LNR and survival in patients with LAGC who underwent radical resection after NICT. Methods A retrospective analysis was performed on 121 cases of LAGC in patients underwent radical resection after NICT between July 2020 and October 2023. The LNR values of the patients were divided into two groups using X-tile software. The first group, designated the low LNR group, comprised patients with LNR values of <= 33%. The second group, designated the high LNR group, comprised patients with LNR values of > 33%. The correlation between patient survival rates and a range of clinical and pathological variables was examined. Results Overall, 121 patients were enrolled: 108 with low-LNR (LNR <= 33%) and 13 with high-LNR (LNR > 33%). A better 2-year overall survival (OS) (88.5% vs. 32.6%; p < 0.001) and progression-free survival (PFS) (80.2% vs. 23.5%; p < 0.001) were observed in patients with low LNR. A similar result was also found in those with non-pathological complete response group (non-pCR), where the 2-year OS was 87.2% vs. 32.6% (p < 0.001), and the 2-year PFS was 77.7% vs. 23.5% (p < 0.001). Compared to the pathologic lymph nodes staging (ypN), LNR exhibited similar prognostic capabilities for OS and PFS. Multivariate analysis indicated that LNR was an independent prognostic factor for both OS (HR 6.258, 95% CI 1.798-21.778; p = 0.004) and PFS (HR 3.431, 95% CI 1.341-8.780; p = 0.010), but not ypN. Conclusions LNR may serve as a viable indicator for prognostication in LAGC patients treated with NICT.