Prognostic Value of Systemic Immune Index in Patients withMetastatic Gastric Cancer

Abstract

Objective: Immune indexes are used to predict prognosis and survival in patients with cancer. Systemic immune-inflammation index (SII) is an index that is calculated using neutrophils (N), lymphocytes (L), and platelet (P) counts (SII=N x P/L). SII is shown to be associated with prognosis in many tumors. The objective of this study is to evaluate the relationship between SII and prognosis in patients with metastatic gastric cancer.Methods: In this study, the data of 187 patients who were followed up with the diagnosis of metastatic gastric cancer in the medical oncology outpatient clinic of the tertiary training and research hospital were retrospectively reviewed. SII was calculated using the formula N x P/L and the optimal cut-off was determined as 600, which was the median value. Values below 600 were grouped as low SII and values above 600 were grouped as high SII. The effect of SII on survival was evaluated by the log-rank test and the Kaplan-Meier curve.Results: For the study, medical files of 253 patients who were diagnosed with metastatic gastric cancer were scanned. Patients who had no follow-up and whose pre-treatment hemogram data were not available at that time were excluded. Finally, this study included 187 patients. In total, there were 63 (33.7%) female and 124 (66.3%) male patients, with a median age of 63 (27-88) years. Although survival was shorter in patients with SII above 600, no statistical significance was detected (9 months vs. 12 months; p=0.13). In primary surgically resected patients, survival was significantly better (13 months vs. 4 months p