Age- and sex- specific rate of venous thromboembolism in cancer survivors: a nationwide cohort study

Abstract

Abstract Background Patients with cancer have an increased risk of venous thromboembolism (VTE) initially, then to decrease over time. VTE might be potentially preventable with pharmacologic prophylaxis, particularly in high-risk patients. The long-term risk of VTE among cancer survivors, however, has not been reported. Purpose We investigated the rate of VTE in survivors of various cancers 5 years out from diagnosis, overall and according to age and sex. Methods Using Danish nationwide registries, five-year survivors of 20 cancers (diagnosed between 1994 and 2013; >15 years at diagnosis) were matched on age and sex with four non-cancer controls from the general population. Rates of VTE in the cancer and non-cancer groups were compared with Cox regression models, overall and according to age (i.e., 15-39, 40-64, and >65 years) and sex. Results In total, 197,702 five-year cancer survivors (median age at diagnosis 63 years [IQR: 53 – 71 years]; 38.5% men) were matched with 790,808 non-cancer controls. During a median follow-up of 6.2 years, cancer survivors overall had a higher associated rate of incident VTE than non-cancer controls (incidence rate per 1,000 person-years 5.6 [95% CI, 5.5-5.8] and 3.3 [3.3-3.4] for cancer survivors and non-cancer controls, respectively; adjusted hazard ratio [aHR] 1.77 [1.72-1.83]). The increased rate of VTE in cancer survivors, compared with matched controls, was statistically significant for all 20 cancer subtypes and was more pronounced in multiple myeloma and lung cancer [Figure 1]. The relatively higher rate of VTE in cancer survivors was more pronounced in women, and the younger patients (age group: 15-39 years) (PInteraction<0.01). Though, VTE was more prevalent in men (per 1,000 person-years 6.7 [95% CI, 6.4-6.9]) than in women (5.2 [95% CI, 5.0-5.3]), and in older patients (8.5 [95% CI, 8.2-8.7]) compared with younger patients (2.2 [95% CI, 1.9-2.4]) [Figure 2]. Conclusions Compared with the general population, five-year cancer survivors had higher associated rates of VTE, irrespective of age and sex. The increased relative rate of VTE was more pronounced in the younger individuals and women.Hazard ratios of venous thromboembolismVenous thromboembolism by age and sex