Systemic immune-inflammation index: A new indicator of predicting 1-, 2-and 3-year disease-free survival of patients with colon cancer

Background. The systemic immune-inflammation index (SII) is a useful prognostic indicator for some types of cancer, but it remains to be elucidated if it is similarly useful for colon cancer. Objectives. This study aims to investigate the prognostic value of preoperative SII in patients with colon cancer undergoing radical surgery. Materials and methods. The clinical materials of 188 patients with colon cancer who underwent radical surgery from September 1, 2013, to August 31, 2018, in Zhongda Hospital at Southeast University (Nanjing, China) were collected retrospectively. The SII was calculated as platelet count x neutrophil count / lymphocyte count. All patients enrolled in the study were then assigned into 2 different groups according to the median value of SII for comparison of clinical features between the 2 groups. The survival curve was drawn using the Kaplan-Meier method. Univariate and multivariate analysis were performed using the Cox regression model, analyzing the independent risk factors. The independent factors were analyzed with the R software to construct a nomogram of 1-, 2- and 3-year disease-free survival (DFS) after operation. Lastly, a web-based probability calculator was constructed to dynamically predict the possibility of DFS of patients. Results. The SII could significantly predict DFS of patients with colon cancer with the median value of 514.13xs. For DFS, multivariate Cox analysis indicated that age, tumor location, pathological N stage, and preoperative SII level were independent risk factors for patients with colon cancer after radical resection (p < 0.05). A nomogram and a web-based probability calculator were constructed based on these factors. Conclusions. The preoperative SII level can predict DFS in patients who received radical surgery with colon cancer. The nomogram constructed based on independent risk factors is helpful in predicting DFS of colon cancer patients in clinical practice.