Cause Of Death And Risk Factors For Death In Patients With Thyroid Cancer

ObjectiveTo study the distribution characteristics of the causes of death of thyroid cancer patients,analyze the risk of death due to cardiovascular comorbidities in patients with thyroid cancer,and explore the related risk factors of relatively high risk of death in patients,so as to provide reference basis and new ideas that can guide clinical decision-making for improving the survival and quality of life of such patients.MethodA total of 183,641 patients diagnosed with thyroid malignancy were screened from the Surveillance,Epidemiology,and End Results Program(SEER)database(1975-2016).Cumulative mortality rates(CMR)were calculated to identify diseases with higher mortality rates in thyroid cancer patients and identify features associated with a higher risk of death.Thyroid cancer patients were compared to the general(no history of cancer)population in the United States and identified possible higher risk factors for death in thyroid cancer patients by calculating Standardized mortality ratios(SMRs)for various non-cancer-related causes of death.During the follow-up period of the study,the mortality rate of various causes of death in thyroid cancer patients was comprehensively compared,and the corresponding risk factors were screened.Outcome1.During the follow-up period,a total of 22,386 deaths were recorded,of which31.0% were attributed to thyroid cancer,22.6% to second or multiple primary cancers,and up to 46.4% of deaths were attributable to non-cancer comorbidities.2.The risk of death from non-cancer comorbidities in patients with thyroid cancer(SMR = 1.59,95% CI: 1.56-1.62)was nearly 1.6 times that of the reference population,and the risk of death was significantly increased by hypertension(SMR =2.41,95% CI: 2.06-2.83),nephritis and nephrotic syndrome(SMR = 2.37,95% CI:2.11-2.65),and Alzheimer’s disease(SMR=2.96,95% CI:2.66-3.29)。3.The distribution of causes of death in thyroid cancer patients changes with the prolongation of time after cancer diagnosis.Cancer-related causes of death are the leading cause of death in such patients shortly after cancer diagnosis;The risk of long-term death is mainly due to non-cancer comorbidities.4.Compared with the reference population,patients with thyroid cancer had an increased risk of death from suicide within the first year after cancer diagnosis(< 1year: SMR=1.51,95% CI: 1.04-2.20);non-cancer comorbidities(1-5 years:SMR=0.90,95% CI: 0.87-0.94)within 1 to 5 years of cancer diagnosis;Alzheimer’s disease(> 5 years: SMR = 8.27,95% CI: 7.37-9.28)significantly increased risk of long-term death.5.The risk of death in patients with thyroid cancer is related to its sociological characteristics,treatment methods,and stage at the time of diagnosis.6.Cardiovascular disease(CVD)-related deaths account for the majority of noncancer deaths in thyroid cancer patients(21.3% of all deaths in thyroid cancer patients).Older age,black ethnicity,male,distant metastasis at the time of diagnosis,and lack of surgical treatment are the risk factors for CVD-related death in patients with thyroid cancer.7.Patients with thyroid cancer had a higher risk of death from CVD compared with the reference population(SMR = 1.59,95% CI: 1.55-1.64).The risk of death from CVD in patients with thyroid cancer was lowest at 1 to 5 years after cancer diagnosis(SMR = 0.91,95% CI: 0.86-0.97)and highest at more than 5 years after diagnosis(SMR = 2.23,95% CI: 2.15-2.30).Conclusion1.The leading cause of death in thyroid cancer patients is no longer thyroid cancer itself but non-cancer comorbidities,which have become the leading cause of death in thyroid cancer patients.2.The mortality rate of non-cancer comorbidities(especially cardiovascular comorbidities)in patients with thyroid cancer is higher than that of other causes.3.As the time after cancer diagnosis increases,the mortality rate caused by thyroid cancer itself continues to decrease,while the number of deaths caused by noncancer comorbidities,especially cardiovascular comorbidities,gradually increases.4.Patients with thyroid cancer have a higher risk of dying from kidney disease,infectious diseases,and cardiovascular diseases,especially hypertension and Alzheimer’s disease,compared with the reference population.