Peripheral Venous Blood Platelet-to-Lymphocyte Ratio (PLR) for Predicting the Survival of Patients With Gastric Cancer Treated With SOX or XELOX Regimen Neoadjuvant Chemotherapy

Abstract

Background: Inflammation plays an important role in tumor progression. Predicting survival is remarkably difficult in patients with gastric cancer receiving neoadjuvant chemotherapy. The aim of the present study is to investigate the potential prognostic significance of the platelet-to-lymphocyte ratio in patients with gastric cancer receiving S-1 plus oxaliplatin or oxaliplatin and capecitabine regimen.

Methods: Ninety-one patients with gastric cancer treated with neoadjuvant chemotherapy were enrolled in this study and then underwent operation. The optimal cutoff value was calculated using receiver-operating characteristic curve analyses. The optimal cutoff value of platelet-to-lymphocyte ratio was divided into low platelet-to-lymphocyte ratio <162 group and high platelet-to-lymphocyte ratio ≥162 group. Kaplan-Meier method and log-rank test were used to analyze the survival curves. The independent prognostic factors and prognostic value of the platelet-to-lymphocyte ratio were assessed by univariate and multivariate Cox proportional hazards regression model. The toxicity was evaluated according to the National Cancer Institute Common Toxicity Criteria.

Results: Kaplan-Meier analyses revealed that patients with low platelet-to-lymphocyte ratio correlated remarkably with better mean disease-free survival and mean overall survival than those with high platelet-to-lymphocyte ratio (mean disease-free survival 47.33 and 33.62 months, respectively; mean overall survival 51.21 and 36.80 months, respectively). The results demonstrated that platelet-to-lymphocyte ratio had prognostic significance using the cutoff value of 162 on disease-free survival and overall survival, and the mean disease-free survival and overall survival time for patients with low platelet-to-lymphocyte ratio were longer than those with high platelet-to-lymphocyte ratio. Meanwhile, patients with gastric cancer who had lower platelet-to-lymphocyte ratio had longer 1-, 3-, and 5-year rates of disease-free survival and overall survival. Moreover, patients with low platelet-to-lymphocyte ratio had longer mean disease-free survival and overall survival than those with high platelet-to-lymphocyte ratio in receiving S-1 plus oxaliplatin or oxaliplatin and capecitabine regimen.

Conclusions: The preoperative platelet-to-lymphocyte ratio may be a promising and convenient prognostic biomarker for patients gastric cancer receiving S-1 plus oxaliplatin or oxaliplatin and capecitabine regimen neoadjuvant chemotherapy. It may be useful to help the doctors identify the high-risk patients for taking efficient treatment strategy decisions.

Keywords: S-1 plus oxaliplatin; gastric cancer; neoadjuvant chemotherapy; oxaliplatin and capecitabine; platelet-to-lymphocyte ratio.

Figure 1.

Disease-free survival (DFS) and overall survival (OS) of patients with gastric cancer. (A) Kaplan-Meier analysis of DFS for the platelet-to-lymphocyte ratio (PLR) of all patients with gastric cancer; (B) Kaplan-Meier analysis of OS for the PLR of all patients with gastric cancer.

Figure 2.

The 1-, 3-, and 5-year rates of DFS and OS in patients with gastric cancer. (A) The 1-, 3-, and 5-year rates of DFS for the PLR of all patients with gastric cancer; (B) the 1-, 3-, and 5-year rates of OS for the PLR of all patients with gastric cancer. DFS indicates disease-free survival; PLR, platelet-to-lymphocyte ratio; OS, overall survival.

Figure 3.

Disease-free survival (DFS) and overall survival (OS) for the platelet-to-lymphocyte ratio (PLR) of patients with gastric cancer in platelet counts. (A) Kaplan-Meier analysis of DFS for the PLR of patients with gastric cancer in low platelet counts; (B) Kaplan-Meier analysis of OS for the PLR of patients with gastric cancer in low platelet counts; (C) Kaplan-Meier analysis of DFS for the PLR of patients with gastric cancer in high platelet counts; (D) Kaplan-Meier analysis of OS for the PLR of patients with gastric cancer in high platelet counts.

Figure 4.

Disease-free survival (DFS) and overall survival (OS) for the platelet-to-lymphocyte ratio (PLR) of patients with gastric cancer in lymphocyte counts. (A) Kaplan-Meier analysis of DFS for the PLR of patients with gastric cancer in low lymphocyte counts; (B) Kaplan-Meier analysis of OS for the PLR of patients with gastric cancer in low lymphocyte counts; (C) Kaplan-Meier analysis of DFS for the PLR of patients with gastric cancer in high lymphocyte counts; (D) Kaplan-Meier analysis of OS for the PLR of patients with gastric cancer in high lymphocyte counts.

Figure 5.

Disease-free survival (DFS) and overall survival (OS) for the PLR of patients with gastric cancer in SOX or XELOX regimen. (A) Kaplan-Meier analysis of DFS for the PLR of patients with gastric cancer in SOX regimen; (B) Kaplan-Meier analysis of OS for the PLR of patients with gastric cancer in SOX regimen; (C) Kaplan-Meier analysis of DFS for the PLR of patients with gastric cancer in XELOX regimen; (D) Kaplan-Meier analysis of OS for the PLR of patients with gastric cancer in XELOX regimen. PLR indicates platelet-to-lymphocyte ratio; SOX, S-1 plus oxaliplatin; XELOX, oxaliplatin and capecitabine.