Patients with cancer have an increased risk of developing venous thromboembolism (VTE), and this combination is reported to result in poorer survival compared with cancer alone. This study aimed to... Show morePatients with cancer have an increased risk of developing venous thromboembolism (VTE), and this combination is reported to result in poorer survival compared with cancer alone. This study aimed to investigate the impact of VTE on the survival of patients with cancer in a general population. The Scandinavian Thrombosis and Cancer (STAC) cohort, a population-based cohort including 144 952 participants 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. The survival of participants without cancer and/or VTE ("disease-free") was compared with the survival of participants 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. Subanalyses 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 participants developed cancer, and 2444 developed VTE, of which 1241 were cancer-related. The mortality rates (per 100 person years) for disease-free participants, VTE only, cancer only, and cancer-related VTE were 0.63, 5.0, 9.2, and 45.3, respectively. Compared with patients with cancer only, the risk of death for patients with cancer-related VTE was increased 3.4-fold. Within all cancer types, the occurrence of VTE increased the mortality risk 2.8-to 14.7-fold. In a general population, patients with cancer with VTE had a 3.4-fold higher mortality risk than patients with cancer without VTE, independent of cancer type. Show less
Smoking is a well-established risk factor for cancer, and cancer patients have a high risk of venous thromboembolism (VTE). Conflicting results have been reported on the association between smoking... Show moreSmoking is a well-established risk factor for cancer, and cancer patients have a high risk of venous thromboembolism (VTE). Conflicting results have been reported on the association between smoking and risk of VTE, and the effect of smoking on VTE-risk in subjects with cancer is scarcely studied. We aimed to investigate the association between smoking and VTE in subjects with and without cancer in a large population-based cohort. The Scandinavian Thrombosis and Cancer (STAC) cohort included 144,952 participants followed from 1993-1997 to 2008-2012. Information on smoking habits was derived from self-administered questionnaires. Active cancer was defined as the first two years following the date of cancer diagnosis. Former smokers (n = 35,890) and those with missing information on smoking status (n = 3680) at baseline were excluded. During a mean follow up of 11 years, 10,181 participants were diagnosed with cancer, and 1611 developed incident VTE, of which 214 were cancer-related. Smoking was associated with a 50% increased risk of VTE (HR 1.49, 95% CI 1.12-1.98) in cancer patients, whereas no association was found in cancer-free subjects (HR 1.07, 95% CI 0.96-1.20). In cancer patients, the risk of VTE among smokers remained unchanged after adjustment for cancer site and metastasis. Stratified analyses showed that smoking was a risk factor for VTE among those with smoking-related and advanced cancers. In conclusion, smoking was associated with increased VTE risk in subjects with active cancer, but not in those without cancer. Our findings imply a biological interaction between cancer and smoking on the risk of VTE. Show less
