Uterine Fibroids Increase the Risk of Thyroid Cancer

Abstract

Objectives: The formation of uterine fibroids (UF) is potentially linked to the development of thyroid cancer through a common factor: female sex hormones. Methods: We conducted a nationwide population-based cohort study to determine whether Taiwanese women with UF have an increased risk of thyroid cancer. The data of both the UF and control groups were derived from the National Health Insurance Research Database (NHIRD) of Taiwan. Groups were matched by the year of UF diagnosis, age, income, urbanization level, occupation, and comorbidities. A Cox proportional hazard regression model was used to compare the incidence of thyroid cancer between the UF and control groups. In addition, the model was used to determine the hazard ratio of thyroid cancer in the UF group in comparison with the control group. Results: Women with UF had a statistically significantly increased risk of thyroid cancer compared with controls (adjusted hazard ratio (aHR): 1.64, 95% confidence interval (CI): 1.26–2.13). Stratified analyses showed that women with UF who had a significantly increased risk of thyroid cancer were more likely to be middle aged, have middle and higher income levels, and a medium follow-up period (1–5 years) of UF. No other UF patient characteristics and comorbidities showed association with the risk of thyroid cancer. In addition, UF patients had a significantly increased risk of thyroid cancer regardless of whether or not they underwent myomectomy. Conclusions: The results suggest that women with UF have an increased risk of subsequent thyroid cancer. Further research is needed to explore whether surveillance strategies for the early detection of thyroid cancer using ultrasonography should be implemented among patients with UF.

Association between Uterine Fibroid and Benign Thyroid Disease: Nationwide Population-Based Cohort Study

“…9 In an analysis using the national health insurance research database of Taiwan, like this study, Sun et al reported that uterine broids increased the risk of thyroid cancer. 6 Our ndings are consistent with the previous studies showing that patients with uterine broids had more benign thyroid diseases such as hypothyroidism and thyroid nodules.…”

“…Previous studies have evaluated the association between uterine broids and thyroid diseases [6][7][8][9] .…”

“…7,8 It was reported the association between broids and overt hypothyroidism. 9 However, these studies have limitations, such as a study with a small number of patients 7,8 , a study not performing propensity matching although largescale national data 6 , and not a comprehensive study of benign thyroid disease. [6][7][8][9] Using a nationwide population-based database for a cohort study can provide signi cantly more data than a cohort-based on multiple institutions.…”

“…9 However, these studies have limitations, such as a study with a small number of patients 7,8 , a study not performing propensity matching although largescale national data 6 , and not a comprehensive study of benign thyroid disease. [6][7][8][9] Using a nationwide population-based database for a cohort study can provide signi cantly more data than a cohort-based on multiple institutions. Therefore, this study aimed to evaluate the relationship between uterine broid and benign thyroid disease using Korean Health Insurance Review and Assessment Service (HIRA) data.…”

“…In a study in 1989, women who have undergone a hysterectomy for uterine broids had signi cantly more frequent pathological thyrotrophin-releasing hormone (TRH)/thyroid stimulating hormone (TSH) stimulation test results and more anti-peroxidase antibody and/or thyroglobulin antibodies compared to the control group. 5 Recent studies showed that women with broids had a higher risk of thyroid cancer 6 and thyroid nodules. 7,8 It was reported the association between broids and overt hypothyroidism.…”