BACKGROUND Data on venous thromboembolism (VTE) in gastric cancer (GC) are very scarce.

OBJECTIVE To investigate the incidence, risk factors and prognostic implications of VTE in Asian GC patients.

METHODS Prospective databases containing clinical information on GC patients (n = 2,085) were used.

RESULTS The 2-year cumulative incidences of all VTE events were 0.5%, 3.5% and 24.4% in stages I, II-IV(M0) and IV(M1), respectively. Advanced stage, older age and no major surgery were independent risk factors for developing VTE. When the VTE cases were classified into extremity venous thrombosis (EVT), pulmonary thromboembolism (PTE) or intra-abdominal venous thrombosis (IVT), IVTs (62%) were more common than EVTs (21%) or PTEs (17%). Although peri-operative pharmacologic thromboprophylaxis was not routinely administered, the VTE incidence after major surgery was only 0.2%. During chemotherapy, EVT/PTE developed more frequently than IVT (54% vs. 19%); however, during untreated or treatment-refractory periods, IVT developed more frequently than EVT/PTE (69% vs. 36%). In multivariate models, the development of EVT/PTE was a significant predictor of early death when compared with no occurrence of VTE (P < 0.05). However, IVT did not affect survival.

CONCLUSION This is the largest study that specially focused on VTE in GC and the VTE incidence in Asian GC patients was first demonstrated. Considering the low incidence of post-operative VTE development, the necessity of peri-operative pharmacologic thromboprophylaxis should be evaluated separately in Asian patients. The clinical situation of the development of EVT/PTE and IVT differed. Only EVT/PTE had an adverse effect on survival and IVT had no prognostic significance.