Risk Factors for Cardiovascular Disease Among Thyroid Cancer Survivors: Findings From the Utah Cancer Survivors Study

Abstract

Context: Thyroid cancer survivors are at high risk of developing multiple cardiac and vascular conditions as consequence of cancer diagnosis and treatment. However, it is still unclear how the baseline and prognostic factors, as well as cancer treatments, play a role in increasing cardiac and vascular disease risk among thyroid cancer survivors.

Objective: To investigate the association between potential risk factors, treatment effects, and cardiovascular disease (CVD) outcomes in thyroid cancer survivors.

Design, setting, patients: Primary thyroid cancer survivors, diagnosed from 1997 to 2012 (n = 3822), were identified using the statewide Utah Population Database. The medical records were used to ascertain information on risk factors and CVD outcomes. Cox proportional hazards models were used to assess the risk of CVD with baseline demographic data and clinical factors.

Results: Among thyroid cancer survivors, age and year at cancer diagnosis, cancer stage, sex, baseline body mass index, baseline comorbidities, and TSH suppression therapy were significantly associated with CVD risk 1 to 5 years after cancer diagnosis. Patients who were male, overweight or obese, older at cancer diagnosis, and diagnosed with cancer since 2005 had an increased risk of CVD compared with patients who were female, had a normal body mass index, were younger at cancer diagnosis, and diagnosed with cancer from 1997 to 1999. Administration of TSH suppression therapy, distant metastases at cancer diagnosis, and a higher Charlson comorbidity index score were associated with an increased CVD risk among thyroid cancer survivors.

Conclusions: Our findings suggest that examining the effect of thyroid cancer diagnosis, cancer treatment, and demographic characteristics on the risk of CVD is critical.

Figure 1.

Potential risk factors for CVD among thyroid cancer survivors, 1 to 5 y after cancer diagnosis. *For the models that violated proportional hazards assumptions, we used Cox models with cubic splines. ^aAdjusted for age at diagnosis, BMI at baseline, and CCI score. ^bAdjusted for diagnosis year, race, sex, BMI at baseline, and CCI score. ^cAdjusted for diagnosis year, age at diagnosis, race, sex, and CCI score. ^dAdjusted for diagnosis year, age at diagnosis, race, sex, BMI at baseline, and CCI score. ^eAdjusted for diagnosis year, age at diagnosis, race, sex, BMI at baseline, cancer stage at diagnosis, and CCI score. ^fAdjusted for diagnosis year, age at diagnosis, race, sex, and BMI at baseline.