Correlation between systemic immune-inflammation index and prognosis of patients with gastric cancer after radical resection / 中华消化杂志

ABSTRACT

Objective:To investigate the clinical value of systemic immune-inflammation index (SII) based on peripheral blood neutrophils, lymphocytes and platelets counts in predicting the prognosis of patients with gastric cancer after radical resection.Methods:From January 1, 2012 to January 1, 2015, the data of 2 273 patients with gastric cancer who underwent radical surgery at the Third Department of Surgery of the Fourth Hospital of Hebei Medical University were retrospectively analyzed. SII value was calculated according to the formula (SII=neutrophil cell count (×10 9/L)×platelet cell count (×10 9/L)/lymphocyte count (×10 9/L)). According to receiver operating characteristic curve (ROC), the optimal cut-off value of SII was determined and the patients were divided into high SII group and low SII group. Chi-square test was used to compare the clinicopathological characteristics and prognosis of the two groups. Kaplan-Meier method was applied to draw survival curve, log-rank test was used for univariate survival analysis, and Cox regression model was used for multivariate survival analysis. The ROC of preoperative SII, pathological TNM stage and their combination for predicting prognosis and recurrence were drawn, and the area under the curve (AUC) values were calculated to compare the predictive power of the three. Results:According to the ROC, the optimal cut-off value of SII was 589.5, and there were 1 180 cases (51.91%) in the high SII (SII≥589.5) group and 1 093 cases (48.09%) in the low SII (SII<589.5) group. Compared with those of the low SII group, the maximum diameter of gastric cancer in the high SII group was mostly ≥5 cm (49.04%, 536/1 093 vs. 56.27%, 664/1 180), the histological types were mostly poorly differentiated to undifferentiated (55.63%, 608/1 093 vs. 61.19%, 722/1 180), the depth of tumor invasion was mainly from T4a to T4b (45.11%, 493/1 093 vs. 54.837%, 647/1 180), and the rate of lymph node metastasis, pathological TNM stage, rate of vascular infiltration, incidence of nerve invasion, Ki-67 expression level, serum carcinoembryonic antigen level and carbohydrate antigen 19-9 level in the high SII group were all higher than those in the low SII group (67.70%, 740/1 093 vs. 80.68%, 952/1 180; 57.64%, 630/1 093 vs. 71.10%, 839/1 180; 55.54%, 607/1 093 vs. 67.03%, 791/1 180; 53.89%, 589/1 093 vs. 64.32%, 759/1 180; 45.29%, 495/1 093 vs. 56.69%, 669/1 180; 56.91%, 622/1 093 vs. 63.20%, 734/1 180; 53.25%, 582/1 093 vs. 57.97%, 684/1 180), and the differences were statistically significant ( χ2=8.842, 11.097, 7.225, 21.467, 50.200, 44.984, 31.687, 25.594, 29.549, 6.612 and 5.119, all P<0.05). The 5-year overall survival rate and disease-free survival rate of the low SII group were 75.66% and 67.61%, respectively, which were both higher than those of the high SII group, (24.92% and 23.31%, respectivily), the differences were statistically significant ( χ2=620.700 and 413.00, both P<0.01). The results of multivariate Cox regression analysis showed that tumor histological type, depth of invasion, pathological TNM stage, vascular invasion and preoperative SII were independent risk factors for postoperative prognosis and recurrence of patients with gastric cancer (odds ratios were 4.126, 2.255, 5.123, 3.826, 6.126, 4.683, 2.472, 5.224, 4.416, 6.212, respectively; 95% confidence interval 2.123 to 9.721, 1.632 to 7.427, 3.325 to 10.211, 2.321 to 9.322, 4.127 to 13.782, 2.561 to 9.418, 1.322 to 6.289, 3.315 to 11.526, 2.213 to 9.382, 4.474 to 13.541; all P<0.05). The predictive power of preoperative SII (AUC=0.842, 0.815) and pathological TNM stage (AUC=0.881, 0.827) for the 5-year overall survival and disease-free survival of patients with gastric cancer after radical resection was similar, however the predictive power of combination of the two (AUC=0.943, 0.895) was higher than that of preoperative SII and pathological TNM stage alone. Conclusions:Preoperative SII is an independent risk factor for the prognosis of patients with gastric cancer after radical resection, combined with parthological TNM stage can be used as an indicator to predict the prognosis and recurrence of patients.