Long-term all-cause mortality and its association with cardiovascular risk factors in thyroid cancer survivors: An Israeli population-based study

Background: The global incidence of thyroid cancer (TC) has risen considerably during the last three decades, while prognosis is generally favorable. We assessed the long-term all-cause mortality in TC survivors compared to the general population, and its association with cardiovascular risk factors. Methods: Individuals diagnosed with TC during 2001-2014 (TC group) and age- and sex-matched individuals from the same Israeli healthcare system without thyroid disease or a cancer history (non-TC group) were compared. Cox regression hazard ratios (HRs) and 95% confidence intervals (95%CIs) for all-cause mortality were calculated by exposure status. Results: During a 15-year follow-up (median 8 years), 577 TC survivors out of 5677 (10.2%) TC patients and 1235 individuals out of 23,962 (5.2%) non-TC patients died. The TC survivors had an increased risk of all-cause mortality (HR = 1.89, 95%CI 1.71-2.10), after adjusting for cardiovascular risk factors already present at follow-up initiation. This increased risk was most pronounced in the 55- to 64-year-old age group (HR = 1.49, 95%CI 1.33-1.67). The TC survivors who died by study closure had more hypertension (14.6% vs. 10.3%, P = 0.002), more dyslipidemia (11.4% vs. 7.2%, P < 0.001), and more cardiovascular disease (33.6% vs. 22.3%, P = 0.05) compared to those who died in the non-TC group. Conclusions: This large cohort study showed higher all-cause mortality with a higher prevalence of hypertension, dyslipidemia, and cardiovascular disease among TC survivors compared to matched non-TC individuals. Primary and secondary prevention of cardiovascular risk factors in TC survivors is mandatory.