Relation between hysterectomy, oophorectomy and the risk of incident differentiated thyroid cancer: The E3N cohort

Abstract

Summary Background Thyroid cancers are threefold more frequent in women than in men. A role of reproductive or hormonal factors has been suggested but with contradictory results. We investigated potential associations between history of hysterectomy, with or without oophorectomy, and history of benign gynaecological disease (uterine fibroids, endometriosis) and the incidence of differentiated thyroid cancer, in a large French prospective cohort. Methods A total of 89 340 women from the E3N cohort were followed up between 1990 and 2012. Gynaecological diseases treated by surgery were self‐reported. Thyroid cancers were validated by histological reports. Time‐dependent covariates included smoking status, BMI and history of benign thyroid disease. Cox proportional hazard models with age as timescale were used to estimate Hazard Ratios (HR) and 95% confidence intervals (CI). Results A total of 412 cases of thyroid cancer were diagnosed during follow‐up. A history of hysterectomy was associated with an increased risk of differentiated thyroid cancer (adjusted HR=2.05; 95%CI: 1.65‐2.55). The association was not altered after further adjustment for reproductive factors. Endometriosis, uterine polyps, ovarian cysts and oophorectomy without hysterectomy were not associated with the risk of thyroid cancer. A history of fibroids was also significantly related to the risk of thyroid cancer over the follow‐up period (adjusted HR=1.91; 95%CI: 1.50‐2.44) and the increased risk persisted after adjustment for history of hysterectomy. Conclusions Women who had either a history of fibroids or hysterectomy had an increased risk of differentiated thyroid cancer. These findings suggest shared biological mechanisms between fibroids and thyroid cancer, which deserve to be further dissected.

Uterine Fibroids Increase the Risk of Thyroid Cancer

“…Guenego et al found that women with a history of UF, irrespective of whether they had a hysterectomy or not, were at a higher risk of thyroid cancer (HR: 1.91; 95% CI: 1.50-2.44). When they considered history of UF and hysterectomy simultaneously, each variable remained statistically associated with the risk of thyroid cancer in the same multivariate statistical model [hysterectomy (yes/no): HR: 1.70, 95% CI: 1.27-2.28; UF (yes/no): HR: 1.33, 95% CI: 1.01-1.75] [13]. Luo et al, indicated that women who had undergone a hysterectomy had a significantly increased risk of thyroid cancer when compared with women who had not undergone a hysterectomy (HR: 1.46, 95% CI: 1.16-1.85) [14].…”

“…Because the occurrence of both UF and thyroid cancer may be related to female hormones, some studies have explored the link between the two diseases and have found that women with a history of UF had a significantly increased risk of thyroid cancer [8,13]. Moreover, researchers also investigated the relationship between hysterectomy and thyroid with inconclusive results [13][14][15]. Through a nationwide database, we designed this study to determine whether Taiwanese women with UF have an increased risk of subsequent thyroid cancer and whether the history of myomectomy affects this possible relationship.…”

What We Know about the Long-Term Risks of Hysterectomy for Benign Indication—A Systematic Review

“…In patients diagnosed with thyroid cancer, the age at initial diagnosis was lower among women with than women without hysterectomy, but survival rates did not differ [44]. Findings from a large, prospective, cohort study in France showed a twofold increased risk of thyroid cancer among women with hysterectomy (n = 80,197) compared with those without (n = 9143) (aHR 2.05; 95% CI 1.65 to 2.55) [42]. This study also showed that a history of fibroids was associated with an increased risk of thyroid cancer (aHR 1.91; 95% CI 1.50 to 2.44), even when adjusted for hysterectomy, leading authors to conclude that further examination is required to determine any shared mechanisms between UF and thyroid cancer.…”

“…These findings suggest that there may be an association between hysterectomy and an increased risk of certain types of cancer, notably thyroid cancer, RCC, bladder cancer, and urinary tract cancer [41][42][43][44]. It is important to acknowledge the potential biases in these studies in that the underlying condition leading to hysterectomy (e.g., obesity, abnormal uterine bleeding, or exposure to ionizing radiation) may be associated with these cancers; therefore, the women included in the studies may be predisposed to them.…”

Thyroid carcinoma in woman. gynecologist view

“…У лонгітюдному дослідженні, яке охопило 89 340 жінок із епідеміологічного дослідження The E3N Cohort (почалось у 1990 р. з метою вивчення факторів ризику онкологічних захворювань у жінок, які були застраховані через французьку національну систему охорони здоров'я, що в першу чергу охоплювала вчителів), A. Guenego et al виявили підвищені ризики розвитку РЩЗ в жінок із обтяженим гінекологічним анамнезом. Так, жінки з лейоміомою матки мали підвищений ризик розвитку РЩЗ в 1,91 раза, а в жінок, яким було проведено гістеректомію з приводу лейміоми матки або ендометріозу, цей ризик збільшувався у 2,05 раза [32].…”