A nomogram can help predict early postoperative deep vein thrombosis (DVT) in gastric and colorectal cancer patients despite routine anticoagulant prophylaxis.

• In this study of 388 patients, 32% had DVT detected by screening, predominantly asymptomatic distal DVT.
• Key predictors for DVT included age, activated partial thromboplastin time, prothrombin time, and postoperative day 1 d-dimer.
• The nomogram demonstrated strong predictive capability with an AUC of 0.854 in the validation cohort, suggesting it could enhance postoperative monitoring, although further validation is needed before clinical use.