Survival after Cancer-related Venous Thrombosis: the Scandinavian Thrombosis and Cancer Study.

Cancer patients have an increased risk of developing venous thromboembolism (VTE) and this combination is reported to result in poorer survival compared to cancer alone. The aim of this study was to investigate the impact of VTE on survival of cancer patients in a general population. The Scandinavian Thrombosis and Cancer (STAC) cohort, a population-based cohort including 144,952 subjects without previous VTE or cancer was used. During follow-up, cancer and VTE incidences were registered. 'Cancer-related VTE' was defined as VTE diagnosed in patients with overt or occult cancer. Survival of subjects without cancer and/or VTE ('disease-free') was compared with survival of subjects with cancer and cancer-related VTE. Cox-regression models with cancer and VTE as time-varying exposures were performed to calculate hazard ratios for death. Sub-analyses were performed across cancer types and stages and VTE type (deep vein thrombosis or pulmonary embolism). During follow-up (mean 11.7 years) 14,621 subjects developed cancer and 2,444 developed VTE, of which 1241 where cancer-related. The mortality rates (per 100 person-years) for disease-free subjects, VTE only, cancer only and cancer-related VTE were 0.63 (95%CI 0.62-0.65), 5.0 (4.6-5.5), 9.2 (9.0-9.5) and 45.3 (41.1-50.0), respectively. Compared with cancer only patients, the risk of death for cancer-related VTE patients was increased 3.4-fold (95%CI 3.1-3.8). Within all cancer types, the occurrence of VTE increased the mortality risk 2.8 to 14.7-fold. In a general population, cancer patients with VTE had a 3.4-fold higher mortality risk than cancer patients without VTE, independent of cancer type.