AIM To investigate the possible predictive role of routinely used glycemic parameters for a first venous thromboembolism(VTE) episode in gastrointestinal(GI) cancer ambulatory patients-with or without clinically diagnosed type 2 diabetes(T2D) or obesity-treated with chemotherapy.METHODS Pre-treatment fasting blood glucose,insulin,glycated hemoglobin(Hb A1c) and homeostasis model of risk assessment(HOMA) were retrospectively evaluated in a cohort study of 342 GI cancer patients. Surgery was performed in 142(42%) patients with primary cancer,30(21%) and 112(79%) of whom received neoadjuvant and adjuvant therapies,respectively. Firstline chemotherapy was administered in 200(58%) patients with metastatic disease. The study outcome was defined as the occurrence of a first symptomatic or asymptomatic VTE episode during active treatment.RESULTS Impaired glucose tolerance(IGT) or T2 D were diagnosed in 30% of GI cancer patients,while overweight/obesity had an incidence of 41%. VTE occurred in 9.4% of patients(7% of non-diabetic non-obese),especially in those with a high ECOG score(P = 0.025). No significant association was found between VTE incidence and T2 D,obesity,different tumor types,metastatic disease,Khorana class of risk,or different anti-cancer drugs,although VTE rates were substantially higher in patients receiving bevacizumab(17% vs 8%,P = 0.044). Conversely,all glucose metabolic indexes were associated with increased VTE risk at ROC analysis. Multivariate Cox proportional analyses confirmed that HOMA index(HR = 4.13,95%CI: 1.63-10.5) or fasting blood glucose(HR = 3.56,95%CI: 1.51-8.39) were independent predictors of VTE occurrence during chemotherapy.CONCLUSION The results here reported demonstrate that evaluating glucose metabolic asset may allow for VTE risk stratification in GI cancer,helping to identify chemotherapy-treated patients who might benefit from thromboprophylaxis. Further multicenter prospective studies involving a larger number of patients are presently needed. AIM To investigate the possible predictive role of routinely used glycemic parameters for a first venous thromboembolism (VTE) episode in gastrointestinal (GI) cancer ambulatory patients-with or without clinically diagnosed type 2 diabetes (T2D) or obesity-treated with chemotherapy. METHODS Pre -treatment fasting blood glucose, insulin, glycated hemoglobin (Hb A1c) and homeostasis model of risk assessment (HOMA) were retrospectively evaluated in a cohort study of 342 GI cancer patients. Surgery was performed in 142 (42%) patients with primary cancer, Firstline chemotherapy was administered in 200 (58%) patients with metastatic disease. The study outcome was defined as the occurrence of a first symptomatic or asymptomatic VTE episode during active treatment. RESULTS Impaired glucose tolerance (IGT) or T2 D were diagnosed in 30% of GI cancer patients, while overweight / obesity had an incidence of 41%. 9.4% of patients (7% of non-diabetic non-obese), especially in those with a high ECOG score (P = 0.025). No significant association was found between VTE incidence and T2D, obesity, different tumor types, metastatic disease , Although the VTE rates were substantially higher in patients receiving bevacizumab (17% vs 8%, P = 0.044) .Conversely, all glucose metabolic indexes were associated with increased VTE risk at ROC analysis Multivariate Cox proportional analyzes confirmed that HOMA index (HR = 4.13, 95% CI: 1.63-10.5) or fasting blood glucose (HR = 3.56, 95% CI: 1.51-8.39) were independent predictors of VTE occurrence during chemotherapy. CONCLUSION The results here describing demonstrated that evaluating glucose metabolic asset may allow for VTE risk stratification in GI cancer, helping to identify chemotherapy-treated patients who might benefit from thromboprophylaxis. Further multicenter prospective studies involving a larger number of patients are presently needed.