Predictive value of systemic immune-inflammation index and serum lactoferrin for postoperative survival in older patients with colon cancer.

BACKGROUND: Systemic immune-inflammation index (SII) combined with serum lactoferrin (LF) level can provide a reference for predicting the postoperative survival and prognosis of older patients with colon cancer. AIM: To evaluate the predictive value of SII combined with serum LF for postoperative survival in older patients with colon cancer. METHODS: This prospective study included 62 older patients [range, 65-85 years; average age (72.46 ± 6.02) years] with colon cancer who underwent radical surgery at our hospital between January 2023 and September 2024. Colon cancer was confirmed on postoperative pathology. All patients underwent peripheral blood, LF, and tumor marker tests and imaging examinations preoperatively. The ability to predict overall survival (OS) and disease-free survival (DFS) by dynamically monitoring the SII [platelet (PLT) count × neutrophil (NEU) count/lymphocyte (LYM) count] and LF levels in combination with postoperative follow-up data was assessed. SII, LF levels, and postoperative data were analyzed using receiver operating characteristic curves, univariate, and multivariate Cox regression analyses to assess OS and DFS. RESULTS: All patients were followed up conventionally postoperatively. There were no significant differences in the patients' baseline data. From 3 months preoperatively until after surgery, the values of routine blood indices (NEUs, LYMs, and PLTs) and SII tended to decrease, but the difference was not statistically significant. The LF level gradually decreased, and there were significant differences at 1 week, 1 month and 3 months postoperatively (P < 0.05). Liver and kidney functions significantly increased 1 week postoperatively and gradually recovered (P < 0.05). The C-reactive protein level significantly increased 1 week postoperatively, whereas the prealbumin level significantly decreased then recovered 3 months postoperatively (P < 0.05). The levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) significantly increased 6 months postoperatively, suggesting an increased risk of recurrence (P < 0.05). Both the OS and DFS showed significant changes over time. Preoperative SII and LF levels had significant predictive values for OS and DFS. In logistics regression analysis, a SII of 585 or greater and LF level less than 185 ng/mL (determined by maximizing the Youden index) correlated with postoperative survival (P < 0.05). Further Cox regression analysis showed that the SII and LF, CA19-9, and CEA levels were independent predictors of postoperative OS (P < 0.05), whereas the tumor, node, metastasis stage; LF level; and SII were independent predictors of DFS. CONCLUSION: This preliminary analysis suggests that the SII and LF levels may predict the survival and prognosis of older patients with colon cancer postoperatively, when assessing the risk of postoperative recurrence and complications. These two categories of indicators have good prognostic evaluation potential in clinical practice and can provide strong support for the development of individualized treatment strategies.