Statin use and thyroid cancer: a population-based case-control study

Antidiabetics, Anthelmintics, Statins, and Beta-Blockers as Co-Adjuvant Drugs in Cancer Therapy

Over the last years, repurposed agents have provided growing evidence of fast implementation in oncology treatment such as certain antimalarial, anthelmintic, antibiotics, anti-inflammatory, antihypertensive, antihyperlipidemic, antidiabetic agents. In this study, the four agents of choice were present in our patients’ daily treatment for nonmalignant-associated pathology and have known, light toxicity profiles. It is quite common for a given patient’s daily administration schedule to include two or three of these drugs for the duration of their treatment. We chose to review the latest literature concerning metformin, employed as a first-line treatment for type 2 diabetes; mebendazole, as an anthelmintic; atorvastatin, as a cholesterol-lowering drug; propranolol, used in cardiovascular diseases as a nonspecific inhibitor of beta-1 and beta-2 adrenergic receptors. At the same time, certain key action mechanisms make them feasible antitumor agents such as for mitochondrial ETC inhibition, activation of the enzyme adenosine monophosphate-activated protein kinase, amelioration of endogenous hyperinsulinemia, inhibition of selective tyrosine kinases (i.e., VEGFR2, TNIK, and BRAF), and mevalonate pathway inhibition. Despite the abundance of results from in vitro and in vivo studies, the only solid data from randomized clinical trials confirm metformin-related oncological benefits for only a small subset of nondiabetic patients with HER2-positive breast cancer and early-stage colorectal cancer. At the same time, clinical studies confirm metformin-related detrimental/lack of an effect for lung, breast, prostate cancer, and glioblastoma. For atorvastatin we see a clinical oncological benefit in patients and head and neck cancer, with a trend towards radioprotection of critical structures, thus supporting the role of atorvastatin as a promising agent for concomitant association with radiotherapy. Propranolol-related increased outcomes were seen in clinical studies in patients with melanoma, breast cancer, and sarcoma.

Smoking, Alcohol Consumption, and the Risk of Thyroid Cancer: A Population-Based Korean Cohort Study of 10 Million People

Background: It is unclear if cigarette smoking and alcohol consumption are associated with thyroid cancer risk. Our aim was to explore for any associations between cigarette smoking and alcohol consumption with thyroid cancer, after adjusting for potential confounders. Methods: Using data from the Korean National Health Insurance database, we retrospectively identified individuals aged ≥20 years who participated in the 2009 health screening program and were followed until 2017. We estimated the adjusted hazard ratio (aHR) for the risk of thyroid cancer using a Cox proportional hazard model, adjusted for age, sex, regular exercise, monthly income, body mass index, diabetes mellitus, and dyslipidemia. Results: During a mean follow-up period of 8.33 ± 0.57 years, of 9,699,104 participants, 89,527 (0.9%) were diagnosed with thyroid cancer. Compared with those who never smoked, current smokers had a lower risk of thyroid cancer (aHR: 0.74, 95% confidence interval [CI]: 0.72-0.76), while ex-smokers did not (aHR: 0.98, 95% CI: 0.96-1.01). There was no significant dose-response relationship with regard to daily amount smoked, duration of smoking, or pack-years. A reduced risk of thyroid cancer was observed in subjects who reported the following categories of alcohol intake (compared with none): mild (aHR: 0.92, 95% CI: 0.90-0.93), moderate (aHR: 0.86, 95% CI: 0.84-0.89), and heavy (aHR: 0.86, 95% CI: 0.82-0.89). Inverse associations with thyroid cancer risk were observed regarding the number of drinking episodes per week and the number of drinks per occasion. A submultiplicative effect of smoking and alcohol consumption was observed (p-interaction <0.001). Conclusions: We observed that thyroid cancer risk was inversely associated with smoking and alcohol consumption, with a significant interaction between these variables.

Changes in Smoking, Alcohol Consumption, and the Risk of Thyroid Cancer: A Population-Based Korean Cohort Study

Simple Summary

The inverse association between smoking, alcohol intake, and thyroid cancer has been suggested by observational studies. From the representative data in Korea, we identified the epidemiologic evidence to elucidate the true effect between smoking, alcohol intake, and thyroid cancer incidence by exploring the effect of changes in smoking and alcohol consumption habits.

Abstract

To elucidate potential causality between smoking and alcohol intake on thyroid cancer incidence, we explored the effect of changes in smoking and alcohol consumption habits. From the Korean National Health Insurance database, we identified 4,430,070 individuals who participated in the national health screening program in 2009 and 2011. The level of smoking and alcohol consumption was measured twice, once in 2009 and again in 2011. The risk of thyroid cancer according to their changes was estimated using the Cox proportional hazard model. During the mean follow-up period of 6.32 ± 0.72 years, 29,447 individuals were diagnosed with thyroid cancer. Compared to those who sustained not smoking, non-smokers who initiated smoking to light (adjusted hazard ratio (aHR) 0.96, 95% confidence interval (CI) 0.81–1.15), moderate (aHR 0.90, 95% CI 0.78–1.04), and heavy level (aHR 0.81, 95% CI 0.69–0.96) had a decreased risk of thyroid cancer. Heavy smokers who quit smoking had an increased risk of thyroid cancer (aHR 1.23, 95% CI 1.06–1.42) compared to those who sustained heavy smoking. Change in drinking status was not significantly associated with thyroid cancer risk compared to drinking at the same level, although a non-significant trend of increased risk was noted in quitters. Participants who initiated both smoking and drinking (HR 0.80, 95% CI 0.69–0.93) had a lower risk of thyroid cancer compared with those who continued not to smoke and drink. Our findings provide further evidence that smoking, and possibly alcohol consumption, would have true protective effects on the development of thyroid cancer.

Evaluation of the relationship between previous statin use and thyroid cancer using Korean National Health Insurance Service-Health Screening Cohort data

The association of thyroid cancer with statin use is controversial. This study aimed to investigate the association of previous statin use with thyroid cancer in the ≥ 40-year-old population in the Korean National Health Insurance Service-Health Screening Cohort. The 5501 patients in the thyroid cancer group were matched with the 22,004 patients in the non-thyroid cancer group for age, sex, income, and region of residence. Previous statin use during the 2 years before the diagnosis of thyroid cancer was examined. The odds ratios (ORs) with 95% confidence intervals (CIs) of previous statin use for thyroid cancer were estimated using conditional logistic regression analyses. Additionally, subgroup analyses were conducted. The thyroid cancer group showed more days of previous statin use than the non-thyroid cancer group (72.3, standard deviation [SD] = 181.2 days vs. 64.3, SD = 174.4 days, P = 0.003). Although the odds of previous statin use for thyroid cancer were high in the crude model (OR = 1.10, 95% CI 1.04–1.17, P = 0.002), they were low in the fully adjusted model (OR = 0.89, 95% CI 0.82–0.95, P = 0.001). According to age and sex subgroups, the younger (< 60 years old) male group showed lower odds for thyroid cancer according to previous statin use (adjusted OR = 0.70, 95% CI 0.55–0.88, P = 0.003), but this finding was not observed in other subgroups of older men or in any groups of women. Thyroid cancer was negatively associated with statin use in the previous 2 years in the adjusted model.

Hypercholesterolemia Is an Associated Factor for Risk of Differentiated Thyroid Cancer in Chinese Population

Background

Hyperlipidemia has been hypothesized as a risk factor for thyroid cancer. However, the association between hypercholesterolemia and thyroid cancer is unclear, especially in Chinese population without available published data. We conducted this study to investigate the relationship between hypercholesterolemia and differentiated thyroid cancer (DTC) in Chinese population.

Methods

Three thousand seven hundred forty-eight patients were enrolled in the study, including 2,021 DTC patients and 1,727 benign subjects with benign thyroid nodules. Demographic characteristics, medical history, and clinical hematological examination were collected. Stratified analyses of association between hypercholesterolemia and risk of DTC were done. Multivariable logistic regression models were used to estimate the association between hypercholesterolemia and the risk of thyroid nodules being malignant. This study protocol was approved by the ethics committee of Shandong Provincial Qianfoshan Hospital and assigned in ClinicalTrials.gov protocol registration and results system (NCT03006289, https://clinicaltrials.gov/ct2/show/NCT03006289).

Results

The level of serum total cholesterol in patients with DTC is higher than that in benign subjects (P < 0.001). After adjusting hypercholesterolemia, age (P < 0.001), triglyceride (P = 0.003), and thyroid stimulating hormone (TSH) (P < 0.001) are found to be confounding factors. The risk of DTC in patients younger than 45 years old is 2.08 times than that of patients older than 45 years old (odds ratio = 0.48, 95% CI (0.38, 0.61), P < 0.001). A high TSH level is highly associated with the increased risk of DTC (P < 0.001). The multivariable logistic regression analysis revealed that the absence of hypercholesterolemia could reduce the risk of thyroid nodules being malignant (odds ratio = −0.75, 95% CI (−1.39, −0.12), P = 0.02). Comparing to the higher level of serum total cholesterol (>5.7 mmol/L), the closer the serum total cholesterol level is to normal (3.17–5.7 mmol/L), the less the risk of thyroid nodules being malignant is, and this difference is statistically significant (odds ratio = −0.67, 95% CI (−1.31, −0.03), P = 0.040). However, this difference is not found in the group of patients with lower level of total cholesterol (<3.17 mmol/L, odds ratio = 0.43, 95% CI (−1.22, 2.09), P = 0.068), suggesting that hypocholesterolemia is not a protective factor in the risk of thyroid nodules being malignant.

Conclusions

Hypercholesterolemia is an associated factor for risk of DTC in Chinese population.

Is Statin Use Associated With Risk of Thyroid Diseases? Results of a Retrospective Cohort Study

BACKGROUND

Given the ubiquity of statin use and prevalence of thyroid diseases, such as thyroid cancer, hyperthyroidism, and thyroiditis, understanding their association deserves further attention.

OBJECTIVE

To examine the association between statin use and thyroid cancer, thyrotoxicosis, goiter, and thyroiditis.

METHODS

Using Tricare data, 2 propensity score (PS)-matched cohorts of statin users and nonusers were formed: (1) a PS-matched general cohort (all patients aged 30-85 years) and (2) a PS-matched healthy cohort (excluded patients with cardiovascular diseases or severe comorbidities). Outcomes were thyroid cancer, thyrotoxicosis, goiter, and thyroiditis. Odds ratios (ORs) and 95% CIs of outcomes were estimated using conditional regression analysis.

RESULTS

Of 43 438 patients, the PS-matched general cohort matched 6342 statin users to 6342 nonusers. The OR of thyroid cancer was 0.62 (95% CI = 0.39-0.996). There was no significant difference between statin users and nonusers in risk of thyrotoxicosis (OR = 0.88; 95% CI = 0.71-1.09), goiter (OR = 0.9; 95% CI = 0.77-1.03), or thyroiditis (OR = 0.78; 95% CI = 0.53-1.15). In the PS-matched healthy cohort (3351 statin users to 3351 nonusers), there was no difference between statin users and nonusers in any outcome. Limitations of the study include its retrospective observational design and use of administrative codes in outcomes ascertainment.

CONCLUSION AND RELEVANCE

This study did not demonstrate any association of statins with harmful effects on thyroid diseases, which offers assurance to clinicians and patients. Furthermore, statin use appears to be associated with a decreased risk of thyroid cancer, but more studies are needed.