High postoperative neutrophil-lymphocyte ratio and low preoperative lymphocyte-monocyte ratio predict poor prognosis in gastric cancer patients receiving gastrectomy with positive lavage cytology: a retrospective cohort study

Background: Long-term outcomes in gastric cancer patients with positive lavage cytology (CY1) are generally poor. This multi-institutional retrospective cohort study aims to evaluate the clinical significance of the neutrophil-lymphocyte ratio (NLR) and the lymphocyte-monocyte ratio (LMR) in CY1 gastric cancer patients.

Methods: A total of 121 CY1 gastric cancer patients without other non-curative factors, who underwent macroscopically curative resection, were enrolled in this study. The cutoff values of preoperative NLR (pre-NLR), postoperative NLR (post-NLR), preoperative LMR (pre-LMR), and postoperative LMR (post-LMR) were defined by the Contal and O'Quigley method as 2.3, 3.0, 2.5, and 3.2, respectively. A Cox proportional hazard model was used to identify the independent prognostic factors among NLR, LMR, and other clinicopathological factors.

Results: There were significant differences in the overall survival (OS) between the two groups: high post-NLR groups vs. low post-NLR group (median survival time, months) (10.9 vs. 22.8, P = 0.006) and high pre-LMR group vs. low pre-LMR group (21.3 vs. 11.0, P = 0.001). The LMR value elevated significantly after gastrectomy (P = 0.020), although not in the NLR value (P = 0.733). On multivariate analysis, high post-NLR (hazard ratio = 1.506; 95% confidence interval = 1.047-2.167; P = 0.027), low pre-LMR (1.773; 1.135-2.769, 0.012), and no postoperative chemotherapy (1.558; 1.053-2.305, 0.027) were found to be independent prognostic factors for adverse OS.

Conclusions: Because a combination of high post-NLR and low pre-LMR may be an adverse prognostic marker in resectable CY1 gastric cancer patients, it is necessary to conduct a prospective trial to confirm a useful perioperative chemotherapeutic regimen for these patients.