Effects of radioactive iodine treatment on cardiovascular disease in thyroid cancer patients: a nationwide cohort study

Abstract

Background: Radioactive iodine (RAI) treatment is a standard treatment in differentiated thyroid cancer (TC). However, its adverse effects on cardiovascular diseases (CVDs) have not been clearly elucidated. Methods:In this retrospective cohort study based on the Korean National Health Insurance Service-National Health Screening Cohort (2002Cohort ( -2015, we analyzed 4,845 patients with TC with a median followup of 66 months. We evaluated and compared the risk of CVD between patients treated with and without RAI therapy. The primary CVD outcome was defined as a composite of ischemic stroke (IS), ischemic heart disease (IHD), hemorrhagic stroke (HS), or heart failure (HF).Results: Overall, 2,533 patients (52.3%) received RAI treatment with a median cumulative dosage of 103 mCi [interquartile range (IQR), 40-162 mCi]. The incidence of the primary CVD outcome in patients who did not receive RAI therapy and those who did was 17.32 [95% confidence interval (CI), 15.07-19.90] and 13.96 (95% CI, 12.17-16.01) per 1,000 person-years, respectively, indicating an adjusted hazard ratio (HR) of 0.87 (95% CI, 0.71-1.07) after multivariate adjustments for variable confounding factors. The risks of IS (HR, 0.83; 95% CI, 0.51-1.34), IHD (HR, 0.90; 95% CI, 0.71-1.13), HS (HR 1.01; 95% CI, 0.49-2.09), and HF (HR 0.89; 95% CI, 0.49-1.63) were comparable between the patients who received RAI therapy and those who did not. There was no cumulative dose-dependent risk for CVD in TC patients who received RAI treatment.Conclusions: RAI treatment is a prevalent and crucial treatment for TC, and has been used in more than half of TC patients in Korea from 2004 to 2015. This study found no significant between-group difference for the CVD risk in patients with TC who received RAI treatment and those who did not, giving further evidence to allay concerns related to the adverse effects of RAI.

Incidence of stroke in the first year after diagnosis of cancer—A systematic review and meta-analysis

“…Of the 41 studies, 23 ( N = 1,972,059) reported the incidence of ischemic stroke events at 1 year after a diagnosis of cancer ( 13 – 15 , 17 , 18 , 20 , 25 , 26 , 30 , 34 – 36 , 39 – 49 ). The pooled incidence of ischemic stroke events during the first year after a new diagnosis of cancer (see Figure 3 ) was 1.3% (95% CI 1.0–1.8%) with a high degree of statistical heterogeneity present ( I 2 = 99.72%).…”

“…There were 11 studies ( N = 1,361,817) that reported the incidence of ICH at 1 year after a diagnosis of cancer ( 14 , 15 , 17 , 18 , 20 , 25 , 26 , 30 , 34 , 50 , 51 ). The pooled incidences of ICH at 1 year after diagnosis was 0.3% (95% CI 0.1–0.9%) with a high degree of statistical heterogeneity present ( I 2 = 99.46%) ( Figure 4 ).…”

“…Out of 22 studies that reported the combined incidence of ischemic and hemorrhagic stroke at 1 year, eight were cohort studies that included multiple types of cancer ( Supplementary Figure 3 ) ( 12 , 14 , 15 , 25 , 27 , 31 , 33 , 34 ). The remaining 14 studies were limited to specific cancer subtypes including head and neck cancer ( n = 3) ( 16 , 24 , 28 ), hematologic malignancies ( n = 2) ( 19 , 29 ), breast cancer ( n = 2) ( 21 , 23 ), and thyroid cancer ( n = 2) ( 26 , 32 ). There was only one study for each of the following subtypes of cancer: pancreatic, cervical, prostate, colorectal, and hepatic ( 17 , 18 , 20 , 22 , 30 ).…”

Big Data Research in the Field of Endocrine Diseases Using the Korean National Health Information Database

“…Interestingly, a study on the safety of RAI treatment reported that the incidence of leukemia significantly increased (HR, 3.1) in patients who received a cumulative dose of 100 mCi or more, and this has emerged as a major issue [56]. No association was reported between RAI treatment and the occurrence of long-term CVD [57]. In addition, studies on mortality [58,59] and second primary malignancies [60,61] were conducted to obtain insights into the long-term prognosis of thyroid cancer, and cases of simultaneous or sequential occurrence of thyroid cancer and breast cancer were reported [62].…”

Cardiovascular morbidity and mortality as a confounder of prognosis in thyroid cancer

“…Lin et al [34] retrospectively evaluated the association between I-131 therapy for TC and stroke risk in 10,104 Taiwanese DTC survivors (mean age 49.4 years). The participants were classified into two groups that did and did not receive I-131 therapy.…”