Association of smoking and cancer with the risk of venous thromboembolism: the Scandinavian Thrombosis and Cancer cohort

• Published in: Scientific reports 2021-09, Vol.11 (1), p.18752-18752, Article 18752
• Main Authors: Paulsen, Benedikte, Gran, Olga V., Severinsen, Marianne T., Hammerstrøm, Jens, Kristensen, Søren R., Cannegieter, Suzanne C., Skille, Hanne, Tjønneland, Anne, Rosendaal, Frits R., Overvad, Kim, Næss, Inger Anne, Hansen, John-Bjarne, Brækkan, Sigrid K.
• Format: Article
• Language: English
• Subjects: 692/699/67; 692/699/75/593/1839; Adult; Basale medisinske, odontologiske og veterinærmedisinske fag: 710; Basic medical, dental and veterinary science disciplines: 710; Cancer; Female; Humanities and Social Sciences; Humans; Male; Medical disciplines: 700; Medisinske Fag: 700; Metastases; Middle Aged; multidisciplinary; Neoplasms - complications; Neoplasms - epidemiology; Risk Factors; Scandinavian and Nordic Countries - epidemiology; Science; Science (multidisciplinary); Smoking; Thromboembolism; Thrombosis; VDP; Venous Thromboembolism - epidemiology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-98062-0

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 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.