The mortality of venous thromboembolism in hospitalized patients with different gastrointestinal malignancies.

e16036 Background: Venous thromboembolism (VTE) is associated with significant morbidity and mortality in cancer patients. Our study compares the mortality in hospitalized VTE patients among the five most common Gastrointestinal (GI) malignancies which includes esophageal, gastric, pancreatic, colorectal, and hepatobiliary cancers. Methods: A retrospective study was conducted utilizing the Nationwide Inpatient Sample database (NIS) from 2016 to 2018. Patients with Venous thromboembolism (VTE) were identified using ICD 10 codes from all primary discharge diagnoses. Only deep venous thrombosis (DVT) and pulmonary embolism (PE) were considered. Patients with VTE were further divided into groups: esophageal cancer, gastric cancer, pancreatic cancer, colorectal cancer, hepatobiliary cancer, and compared with patients who did not have these malignancies. Patients younger than 18 years of age or patients with missing age, gender or race were excluded. Among the hospitalized patients with VTE, we investigated the difference in mortality with different gastrointestinal malignancies. Adjusted odds ratio (OR) was calculated using multivariate regression analysis. Results: Among 751,834 patients discharged with a VTE diagnosis, 0.24% had esophageal cancer, 0.25% had gastric cancer, 0.93% had pancreatic cancer, 1.10% had colorectal cancer, 0.35% had hepatobiliary cancer, and the other 97.14% did not have these malignancies. The study shows that adults admitted to the hospitals for VTE have higher mortality when compared to patients who did not have GI malignancies, with esophageal cancer having the highest inpatient mortality with an OR of 2.66 (95% CI 1.78-3.94, P of 0.00). For the remaining GI cancers, gastric cancer had an OR of 1.74 (95% CI 1.141-2.661, P of 0.010), pancreatic cancer had an OR of 1.74 (95% CI 1.402-2.178 P of 0.000), hepatobiliary cancer had an OR of 1.67 (95% CI 1.144-2.439 P-value of 0.002) and colorectal cancer had OR of 1.18 (95% CI 0.930-1.517 P of 0.169), which was not statistically significant. Conclusions: Pancreatic and gastric cancers have a higher risk of VTE and frequently score high in validated VTE risk assessment tools such as the Khorana score. This study shows that VTE in hospitalized patients with esophageal cancer is associated with greater mortality. More research is needed to analyze the outcomes of VTE in cancer patients and to identify those who would benefit from thromboprophylaxis. Due to the nature of the NIS database, one of the study's limitations was the difficulty in identifying patients receiving DVT prophylaxis.