From early risk to 1-year mortality: a comprehensive assessment of postoperative venous thromboembolism in upper gastrointestinal cancer patients - a nationwide cohort study.

BACKGROUND: Venous thromboembolism (VTE) is a well-recognized complication following gastrointestinal cancer surgery, particularly early postoperatively. The incidence and risk factors of VTE within 1-year after esophageal (including esophago-gastric junction) (ECS) and gastric (GCS) cancer surgeries, and especially its impact on 1-year global mortality, are yet under-explored. METHODS: This nationwide observational population-based cohort study used data extracted from all patients undergoing ECS and GCS in France between 1 January 2015 and 31 December 2017. Multivariate logistic regression was used to identify risk factors for 90 postoperative days (POD) VTE (OR 95% CI). Cox proportional hazards models investigated the impact of 1-year postoperative VTE on 1-year global mortality [HR (95% CI)]. RESULTS: During the study period, 8005 patients underwent ECS ( N =3429) or GCS ( N =4576) (31.8% female; 66.7±12.1 years old). Majority ( N =4951) of patients had preoperative treatment (chemotherapy or radiochemotherapy). Ninety POD incidence of VTE were 4.7% (ECS=6.2%) (GCS=3.6%) (44.7% during first hospitalization, 19.0% needing readmission, and 36.3% ambulatory management). Main risk factors were three and two field esophagectomy [3.6 (2.20-5.83) and 2.2 (1.68-3.0)], obesity [1.9 (1.40-2.58)] and history of VTE [5.1 (2.72-9.45)]. Late-onset VTE rates (occurring between the 6th and 12th month) represented 1.80 and 1.46% of the overall ECS and GCS groups. Patients with VTE within 1-year had higher risks of 1-year global mortality: (2.04 1.52; 2.73) and 2.71 (2.09; 3.51), respectively. CONCLUSION: Our extensive analysis of a nationwide database highlights the significant risk of postoperative VTE after ECS and GCS, persisting within 90 POD and up to 1-year. Crucially, a higher risk of global mortality within 1-year for patients experiencing early or late VTE was found. These findings could advocate for further research into extended prophylactic regimens, particularly for those most at risk.