Association of comprehensive inflammatory-metabolic status and perioperative outcomes in gastric cancer: insights from four randomized controlled trials.

[BACKGROUND] Inflammatory and metabolic status play a key role in the prognosis of gastric cancer (GC) patients. This study aimed to develop a novel comprehensive inflammatory-metabolic index (CIMI) to predict the risk of perioperative complications and prolonged hospital stay in GC patients.

[PATIENTS AND METHODS] This study included 567 stage II-III GC patients from four randomized, controlled trials RCTs as the development cohort, and 107 patients from an external cohort as the validation set. Preoperative hematological and body composition parameters were used to evaluate inflammatory-metabolic status. The predictive performance of CIMI was evaluated using receiver operating characteristic (ROC), precision-recall (PR), decision curve analysis (DCA) curves, and model fit indices [deviance, Akaike information criterion (AIC), Bayesian information criterion (BIC)]. Subgroup and survival analyses were conducted to further explore the clinical utility of CIMI.

[RESULTS] CIMI was calculated using the formula: log[white blood cell count (10/l) × serum globulin (g/l)] × visceral adiposity index (VAI). In the development cohort, the areas under the curve (AUC) for CIMI were 0.748 (post-operative complications) and 0.651 (length of stay >11 days], outperforming existing inflammatory/metabolic indicators. Similar results were observed in the validation cohort, further confirming its robust predictive ability. Additionally, CIMI was significantly associated with intraoperative surgical time and post-operative recovery time. Subgroup analysis showed that, after adjusting for variables, the high-risk CIMI group had a significantly higher incidence of post-operative complications than the low-risk group (odds ratio = 7.77, 95% confidence interval 4.39-13.75, P < 0.001). Survival analysis revealed that in the low-risk CIMI group, patients who initiated adjuvant chemotherapy within 6 weeks (time to chemotherapy <6 weeks) had a significantly better 5-year overall survival rate than those with time to chemotherapy ≥6 weeks (56.0% versus 45.0%, P = 0.043). The online CIMI calculator provides clinicians with a convenient tool to support individualized treatment decision-making.

[CONCLUSIONS] As a novel inflammatory-metabolic index, CIMI effectively predicts the risk of post-operative complications and prolonged hospital stay in GC patients, providing valuable insights for clinical decision-making and health care system strategies.