Pretreatment platelet-to-lymphocyte ratio (PLR) as a prognosticating indicator for gastric cancer patients receiving immunotherapy

BACKGROUND: Previous investigations suggest that systemic inflammation markers are able to provide prognostic value in several cancers. This study seeks to characterize the ability of pretreatment platelet-to-lymphocyte ratio (PLR) to prognosticate advanced or metastatic gastric cancer patients (AGC or MGC, respectively) receiving immunotherapy. METHODS: AGC and MGC patients exposed to PD-1 inhibitors from January 2016–August 2021 in the Chinese PLA General Hospital were recruited. Correlations between PLR and overall survival (OS), progression-free survival (PFS), and immunotherapy-associated tumor response rates were determined. RESULTS: 237 patients were enrolled for this retrospective investigation. The 6 month and 12 month PFS based on the area under the curve value was 0.60 and 0.65 (p < 0.05). based on a calculated PLR cut-off value of 139.41, The PLR < 139.41 group has a longer OS in contrast with the PLR ≥ 139.41 group (13.46 m vs 10.71 m, HR = 0.57, 95% CI 0.42–0.78, p = 0.004). The PLR < 139.41 group had a PFS of 7.93 m in contrast to the 4.75 m seen in those with PLR ≥ 139.41 group (HR = 0.57, 95% CI 0.43–0.76, p = 0.002). The disease control rate (DCR) and objective response rate (ORR) were 86.17% and 30.85%, respectively, in the PLR < 139.41 group, but were 82.52% and 32.17%, respectively in the PLR ≥ 139.41 group. Both groups did not show any marked differences in terms of ORR and DCR (p = 0.887, p = 0.476). PLR is an independent prognostic indicator for OS and PFS upon uni- and multivariate analyses (p < 0.05). CONCLUSIONS: Pre-treatment PLR correlated significantly with PFS and OS in AGC and MGC patients who received immunotherapy. An elevated PLR may provide guidance on subsequent treatment options.