Association between radioiodine treatment for thyroid cancer and risk of stroke

Vascular events in patients with head and neck cancer: A systematic review and meta-analysis

OBJECTIVE

To assess the incidence of vascular events in patients with head and neck cancer.

REVIEW METHODS

Primary studies identified through April 2023. Meta-analysis was performed.

RESULTS

There were 146 studies included in the systematic review. Rates of events were collected in the overall group, those with chemoprophylaxis, and those that underwent surgery, radiation, or chemotherapy. Of 1 184 160 patients, 4.3% had a vascular event. Radiation therapy had highest risk of overall events and stroke when compared to surgery and chemotherapy. Chemotherapy had a higher risk of stroke and overall events when compared to surgery.

CONCLUSIONS

Vascular events occur in 4%-5% of patients with head and neck cancer. Our data does not support the use of routine anticoagulation. Patients undergoing radiation therapy had the highest frequency of events.

Risk of Adverse Cardiovascular Outcomes in Differentiated Thyroid Cancer Survivors: A Systematic Review and Meta-Analysis

Introduction: Long-term cardiovascular (CV) risk is a concern for differentiated thyroid cancer (DTC) survivors. Methods: We performed a systematic review and meta-analysis evaluating the risks of CV mortality and morbidity in DTC survivors compared with the general population. Respective meta-analyses were conducted for data that were adjusted for relevant confounders and crude data. We searched five electronic databases from inception to October 2021, supplemented with a hand search. Two reviewers independently screened citations, reviewed full text articles, extracted data, and critically appraised the studies, with discrepancies resolved by a third reviewer. The primary outcome was CV mortality. Secondary outcomes included atrial fibrillation, ischemic heart disease, stroke, and heart failure. We estimated the relative risk (RR) and confidence intervals [CI] of outcomes using random-effects models (adjusted for age and gender), compared with the general population. Results: We reviewed 3409 unique citations, 65 full text articles, and included 7 studies. CV mortality risk was significantly increased in DTC survivors in one study adjusted for confounders-adjusted RR (aRR) 3.35 ([CI 1.66-6.67]; 524 DTC, 1572 controls). The risk of CV morbidity in DTC survivors, adjusted for risk factors, was estimated as follows: atrial fibrillation-aRR 1.66 [CI 1.22-2.27] (3 studies, 4428 DTC, I² = 75%), ischemic heart disease-aRR 0.97 [CI 0.84-1.13] (2 studies, 3910 DTC, I² = 0%), stroke-aRR 1.14 [CI 0.84-1.55] (2 studies, 3910 DTC, I² = 69%), and heart failure-aRR 0.98 [CI 0.60-1.59] (2 studies, 3910 DTC, I² = 79%). In meta-analyses of unadjusted data, the risks of CV mortality were not significantly increased but the CV morbidity risks were similar to adjusted data. Conclusions: There is limited evidence suggesting that DTC survivors may be at an increased risk of CV death and atrial fibrillation (after adjustment for confounders). We did not observe a significantly increased risk of ischemic heart disease, stroke, or heart failure. Most analyses were subject to significant heterogeneity and further research, with careful attention to CV risk factors, is needed to clarify CV risk in DTC survivors. Registration: PROSPERO CRD42021244743.

Association between thyroid cancer and cardiovascular disease: A meta-analysis

Objective

To determine the association between thyroid cancer and coronary artery disease, atrial fibrillation, cerebrovascular disease, and cardiovascular disease mortality.

Methods

The PubMed, Embase, and Cochrane Library databases were searched for eligible studies from inception to September 22, 2022. Keywords included "thyroid cancer", "atrial fibrillation", "coronary artery disease", "cerebrovascular disease", and "mortality". Primary outcomes included the incidence of coronary artery disease, cerebrovascular disease, atrial fibrillation, and cardiovascular disease mortality among patients with thyroid cancer. Secondary outcomes included cardiovascular disease events among those with thyroid cancer that received or did not receive radioactive iodine or lenvatinib. Estimates were pooled using fixed- and random-effects meta-analysis.

Results

A total of 771,220 patients who underwent thyroidectomy in 15 studies were included. Risk for cerebrovascular disease (risk ratio [RR] 1.15 [95% confidence interval (CI) 1.10-1.21]) and atrial fibrillation [RR 1.59 (95% CI: 1.45-1.73)] were significantly increased. Risk for coronary artery disease was significantly increased [RR 1.12 (95% CI: 1.08-1.17)] in the common effect model. Cardiovascular disease mortality associated with thyroid cancer was not significant [RR 0.93 (95% CI: 0.59-1.45)]. Radioactive iodine had a neutral effect on cardiovascular disease [RR 1.00 (95% CI: 0.87-1.16)], and there was no beneficial nor harmful effect among different RAI doses.

Conclusions

Thyroid cancer was significantly associated with a higher risk for cerebrovascular disease and atrial fibrillation; however, the hazard risk was not different between patients with and without radioactive iodine treatment. Thyroid cancer treatment should be individualized considering the potential harms and benefits to cardiovascular health.

Radioactive Iodine Treatment and the Risk of Long-Term Cardiovascular Morbidity and Mortality in Thyroid Cancer Patients: A Nationwide Cohort Study

(1) Background: This study aimed to investigate the association between radioactive iodine (RAI) and long-term cardiovascular disease (CVD) morbidity/mortality in thyroid cancer. (2) Methods: The study was conducted using data from the Taiwan National Health Insurance Database during 2000–2015. Thyroid cancer patients aged ≥20 years were categorized into RAI (thyroidectomy with RAI) and non-RAI (thyroidectomy only) groups. The Cox proportional hazard regression model and Kaplan–Meier method were used for analysis. (3) Results: A total of 13,310 patients were included. Kaplan–Meier analysis demonstrated that the two groups had similar cumulative risks of CVD (log-rank p = 0.72) and CVD-specific mortality (log-rank p = 0.62). On Cox regression analysis of different RAI doses, the risk of CVD was higher in the cumulative dosage >3.7 GBq (hazard ratio = 1.69, 95% confidence interval = 1.24–2.40, p < 0.001). (4) Conclusions: RAI was not associated with an increased risk of CVD in thyroid cancer. However, CVD surveillance is indicated in the patients receiving the cumulative RAI dosage above 3.7 GBq.

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

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 (2002–2015), we analyzed 4,845 patients with TC with a median follow-up 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.