Male thyroid cancer survivors are twice as likely to develop cardiovascular disease in the 5 years after diagnosis vs. women, according to findings from a U.S. population-based study.
“Thyroid cancer survivors are at high risk of developing cardiovascular disease,” Mia Hashibe, PhD, of the Huntsman Cancer Institute in Salt Lake City, said in a press release. “Our study found that male thyroid cancer survivors have an almost 50% higher risk of developing CVD than women, while thyroid cancer survivors with obesity have a 41% higher risk.”
Hashibe and colleagues analyzed electronic medical records data from 3,510 patients diagnosed with thyroid cancer between 1997 and 2012 (96.1% white; 78.8% women), identified from the statewide Utah Population Database and Utah Cancer Registry. Researchers assessed age at thyroid cancer diagnosis, year of diagnosis, cancer stage, histology, treatment, thyroid-stimulating hormone suppression therapy and Charlson Comorbidity Index score (calculated using all medical record data before thyroid cancer diagnosis). Researchers assessed CVD diagnoses along with five specific categories: hypertension, heart disease, cerebrovascular disease, diseases of the arteries, arterioles and capillaries, and diseases of veins and lymphatics. CVD diagnoses were stratified during three periods: 1 to 5 years, 5 to 10 years and at least 10 years after cancer diagnosis. Researchers used Cox proportional hazard models to estimate the effect of each risk factor on CVD, with time to event defined as time from thyroid cancer diagnosis to CVD diagnosis.
Within the cohort, 99.3% underwent surgery (thyroidectomy and thyroid lobectomy), and 52.6% received postsurgical radioactive iodine treatment.
In the 1 to 5 years after thyroid cancer diagnosis, 1,719 patients (45%) developed at least one cardiac or vascular disease, according to researchers. Patients who developed CVD were more likely to die in the 5 years after cancer diagnosis vs. those who did not develop CVD (196 vs. 56, respectively; P < .001). Compared with patients free of CVD, those with a CVD diagnosis were more likely to be older men with overweight or obesity, according to researchers.
Researchers found that men diagnosed with thyroid cancer were at greater risk for developing CVD vs. women (HR = 1.46; 95% CI, 1.31-1.62). Additionally, risk for CVD was greater among patients diagnosed with thyroid cancer during 2005-2009 and 2010-2012 when compared with patients diagnosed during 1997-1999, with HRs of 1.42 (95% CI, 1.19-1.69) and 1.26 (95% CI, 1.05-1.51), respectively.
Patients aged at least 65 years had a nearly threefold greater risk for developing CVD after cancer diagnosis vs. those aged 40 years or younger (HR = 2.84; 95% CI, 2.46-3.27), and both overweight and obesity increased the risk for future CVD after thyroid cancer, with HRs of 1.24 (95% CI, 1.11-1.39) and 1.41 (95% CI, 1.25-1.6), respectively. Patients with any comorbidity had a more than fourfold increased risk for developing CVD after thyroid cancer vs. those with no comorbidities (HR = 4.47; 95% CI, 3.87-5.15).
“Despite a high survival rate, thyroid cancer survivors’ risk of CVD events in the first 5 years after cancer diagnosis suggest that evaluating not only patient-specific risk factors but also consequences of cancer diagnosis and its treatment is important to improve quality of life among thyroid cancer survivors,” the researchers wrote. – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.