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

Reproductive Factors and Thyroid Cancer Risk: The Multiethnic Cohort Study

Background: Women are three times more likely to be diagnosed with thyroid cancer than men, with incidence rates per 100,000 in the United States of 20.2 for women and 7.4 for men. Several reproductive and hormonal factors have been proposed as possible contributors to thyroid cancer risk, including age at menarche, parity, age at menopause, oral contraceptive use, surgical menopause, and menopausal hormone therapy. Our study aimed to investigate potential reproductive/hormonal factors in a multiethnic population. Methods: Risk factors for thyroid cancer were evaluated among female participants (n = 118,344) of the Multiethnic Cohort Study. The cohort was linked to Surveillance, Epidemiology, and End Results cancer incidence and statewide death certificate files in Hawaii and California, with 373 incident papillary thyroid cancer cases identified. Exposures investigated include age at menarche, parity, first pregnancy outcome, birth control use, and menopausal status and type. Multivariable Cox proportional hazards models were used to obtain relative risk (RR) of papillary thyroid cancer and their 95% confidence intervals (CI). Covariates included age, race and ethnicity, reproductive history, body size, smoking, and alcohol consumption. Results: We observed a statistically significant increased risk of papillary thyroid cancer for oophorectomy (adjusted RR 1.58, 95% CI: 1.26, 1.99), hysterectomy (adjusted RR 1.65, 95% CI: 1.33, 2.04), and surgical menopause (adjusted RR 1.55, 95% CI: 1.22, 1.97), and decreased risk for first live birth at ≤20 years of age versus nulliparity (adjusted RR 0.66, 95% CI: 0.46, 0.93). These associations did not vary by race and ethnicity (p het > 0.44). Conclusion: The reproductive risk factors for papillary thyroid cancer reported in the literature were largely confirmed in all racial and ethnic groups in our multiethnic population, which validates uniform obstetric and gynecological practice.

Thyroid cancer risk in women after hysterectomy: A nationwide cohort study

OBJECTIVES

Hysterectomy is commonly performed for benign uterine pathologies but there is some controversy over whether it is associated with an increased risk of thyroid cancer. This study examines the associations of hysterectomy with ovarian conservation or with bilateral salpingo-oophorectomy and thyroid cancer incidence in Taiwan.

METHODS

We analyzed data from a nationwide health insurance claims database and identified 29,577 women aged ≥30 years who underwent hysterectomy with ovarian conservation or hysterectomy with bilateral salpingo-oophorectomy between 2000 and 2016. Propensity score-matching analyses were performed at ratios of 1:1 for the hysterectomy and no-hysterectomy groups, to reduce selection bias. We monitored thyroid cancer occurrence in both groups until 2017. Cox regression was used to calculate hazard ratios with 95 % confidence intervals and determine thyroid cancer risk in women who underwent hysterectomy.

RESULTS

The study comprised 29,577 patients who underwent any hysterectomy and 29,577 participants who did not. The mean follow-up period was 10.03 ± 4.92 years. Patients who underwent hysterectomy had higher thyroid cancer incidence (4.72 per 10,000 person-years) than those who did not (3.06 per 10,000 person-years) and a greater risk of any thyroid cancer (adjusted hazard ratio = 1.40; 95 % confidence interval = 1.08-1.82). However, there was no association between hysterectomy with bilateral salpingo-oophorectomy and thyroid cancer incidence (p > 0.05).

CONCLUSIONS

Our findings suggest that women who undergo hysterectomy are at a higher risk of developing thyroid cancer than those who do not.

Long-term outcomes of hysterectomy with bilateral salpingo-oophorectomy: a systematic review and meta-analysis

OBJECTIVE

This study aimed to provide an up-to-date systematic review of "the long-term outcomes of bilateral salpingo-oophorectomy at the time of hysterectomy" and perform a meta-analysis for the reported associations.

DATA SOURCES

Our study updated a previous systematic review by searching the literature using PubMed, Web of Science, and Embase for publications between January 2015 and August 2022.

STUDY ELIGIBILITY CRITERIA

Our study included studies of women who had a hysterectomy with bilateral salpingo-oophorectomy vs women who had a hysterectomy with ovarian conservation or no surgery.

METHODS

The quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations. Adjusted hazard ratios were extracted and combined to obtain fixed effect estimates.

RESULTS

Compared with hysterectomy or no surgery, hysterectomy with bilateral salpingo-oophorectomy in young women was associated with decreased risk of breast cancer (hazard ratio, 0.78; 95% confidence interval, 0.73-0.84) but with an increased risk of colorectal cancer (hazard ratio, 1.27; 95% confidence interval, 1.10-1.47). In addition, it was associated with an increased risk of total cardiovascular diseases, coronary heart disease, and stroke with hazard ratios of 1.18 (95% confidence interval, 1.11-1.25), 1.17 (95% confidence interval, 1.10-1.25), and 1.20 (95% confidence interval, 1.10-1.31), respectively. Compared with no surgery, hysterectomy with bilateral salpingo-oophorectomy before the age of 50 years was associated with an increased risk of hyperlipidemia (hazard ratio, 1.44; 95% confidence interval, 1.25-1.65), diabetes mellitus (hazard ratio, 1.16; 95% confidence interval, 1.09-1.24), hypertension (hazard ratio, 1.13; 95% confidence interval, 1.06-1.20), dementia (hazard ratio, 1.70; 95% confidence interval, 1.07-2.69), and depression (hazard ratio, 1.39; 95% confidence interval, 1.22-1.60). The evidence on the association with all-cause mortality in young women showed substantial heterogeneity between the studies (I2=85%; P<.01).

CONCLUSION

Hysterectomy with bilateral salpingo-oophorectomy was associated with multiple long-term outcomes. The benefits of the addition of bilateral salpingo-oophorectomy to hysterectomy should be balanced against the risks.

Hysterectomy and thyroid cancer risk: A systematic review and meta-analysis

Background

Incidence rates of thyroid cancer have increased. Recent studies findings suggest that women who underwent a hysterectomy have an elevated relative risk of thyroid cancer. The aim of our meta-analysis is to summarize the evidence about the association between hysterectomy and thyroid cancer risk.

Methods

PubMed, Web of Science, and Scopus database were searched for studies published up to 5 September 2023. The PRISMA statement was followed. Heterogeneity was explored with Q statistic and the I2 statistic. Publication bias was assessed with Begg's and Egger's tests.

Results

Sixteen studies met the criteria. The pooled analysis showed a significantly 64% increment of thyroid cancer risk in association with any hysterectomy (OR 1.64, 95% CI 1.48-1.81; I2 = 28.68%, p = 0.156). Hysterectomy without oophorectomy was a stronger predictor of risk than hysterectomy with oophorectomy. The pooled analysis of data regarding hysterectomy without oophorectomy showed a statistically significant increment of thyroid cancer risk by 59%. Hysterectomy with oophorectomy was associated with an increase of thyroid cancer risk of 39% (OR 1.39, 95% CI 1.16-1.67; I2 = 42.10%, p = 0.049). Significant publication bias was not detected.

Conclusions

Our findings help with decision making around these surgeries.

Female Papillary Thyroid Cancer Survivors Are at Increased Risk of Adenomyosis and Endometrial Hyperplasia

PURPOSE

Thyroid cancer (TC) is the most common endocrine cancer worldwide, affecting mainly women of reproductive age. However, no data exist about its association with endometrial or uterine disorders. This study aimed to assess the risk of hyperproliferative pathology of the reproductive system in female ТС survivors.

METHODS

This was a cross-sectional study of female patients aged 20-45 years diagnosed with papillary TC (PTC) from 1994-2018. Age-matched females with normal thyroid structures served as controls.

RESULTS

One hundred and sixteen patients (mean age 36.7±61 years) and 90 age-matched controls were included. PTC survivors demonstrated an increased risk for adenomyosis [odds ratio (OR) 2.5, 95% confidence interval (CI) 1.3-4.8] and endometrial hyperplasia (OR 3.9, 95% CI 1.1-14.3), compared with controls. The risk for adenomyosis was higher after the ten post-operative years (OR 5.3, 95% CI 2.29- 12.05) than during the first 5-10 years (OR 2.3, 95% CI 1.02-5.10) and increased with the number of RAI courses and the degree of TSH suppression. The risk of endometrial hyperplasia was most evident during the first five years post-thyroidectomy (OR 6.0, 95% CI 1.4-25.5), especially in patients with TSH <0.1 mU/L (OR 6.8, 95% CI 1.4-33.28) No difference in uterine leiomyomas or endometrial polyps was found between PTC survivors and controls.

CONCLUSIONS

Female PTC survivors are at increased risk of endometrial hyperplasia and adenomyosis compared with those with normal thyroid structures.

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

Hysterectomy is the most common treatment option in women with uterine fibroids, providing definitive relief from the associated burdensome symptoms. As with all surgical interventions, hysterectomy is associated with risk of complications, short-term morbidities, and mortality, all of which have been described previously. However, information on the potential long-term risks of hysterectomy is only recently becoming available. A systematic literature review was performed to identify studies published between 2005 and December 2020 evaluating the long-term impact of hysterectomy on patient outcomes. A total of 29 relevant studies were identified. A review of the articles showed that hysterectomy may increase the risk of cardiovascular events, certain cancers, the need for further surgery, early ovarian failure and menopause, depression, and other outcomes. It is important to acknowledge that the available studies examine possible associations and hypotheses rather than causality, and there is a need to establish higher quality studies to truly evaluate the long-term consequences of hysterectomy. However, it is of value to consider these findings when discussing the benefits and risks of all treatment options with patients with uterine fibroids to allow for preference-based choices to be made in a shared decision-making process. This is key to ensuring that patients receive the treatment that best meets their individual needs.

Risk of thyroid cancer following hysterectomy

BACKGROUND

Hysterectomy has been associated with increased thyroid cancer risk but whether this reflects a biological link or increased diagnosis of indolent cancers due to greater medical contact remains unclear.

METHODS

We recruited 730 women diagnosed with thyroid cancer and 785 age-matched population controls. Multivariable logistic regression was used to assess the association overall, and by tumour BRAF mutational status as a marker of potentially higher-risk cancers. We used causal mediation analysis to investigate potential mediation of the association by healthcare service use.

RESULTS

Having had a hysterectomy was associated with an increased risk of thyroid cancer (odds ratio [OR] = 1.45, 95 % confidence interval [CI] 1.07-1.96). When stratified by indication for hysterectomy, the risk appeared stronger for those who had a hysterectomy for menstrual disorders (OR = 1.67, 95 % CI 1.17-2.37) but did not differ by tumour BRAF status. Approximately 20 % of the association between hysterectomy and thyroid cancer may be mediated by more frequent use of healthcare services.

CONCLUSIONS

The observed increased risk of thyroid cancer among those with hysterectomy may be driven, at least partly, by an altered sex steroid hormone milieu. More frequent healthcare service use by women with hysterectomy accounts for only a small proportion of the association.

Hysterectomy and Risk of Breast, Colorectal, Thyroid, and Kidney Cancer - an Australian Data Linkage Study

BACKGROUND

This study aimed to investigate the associations between hysterectomy for benign indications and risk of breast, colorectal, kidney, and thyroid cancer, and to explore whether these associations are modified by removal of ovaries at the time of surgery or by age at surgery.

METHODS

We conducted a retrospective cohort study of the female population of Western Australia (n = 839,332) linking data from electoral, hospital, births, deaths, and cancer records. We used Cox regression to estimate HRs and 95% confidence intervals (CI) for the associations between hysterectomy and diagnosis of breast, colorectal, kidney, and thyroid cancers.

RESULTS

Compared with no surgery, hysterectomy without oophorectomy (hysterectomy) and hysterectomy with bilateral salpingo-oophorectomy (hysterectomy-BSO) were associated with higher risk of kidney cancer (HR, 1.32; 95% CI, 1.11-1.56 and HR, 1.29; 95% CI, 0.96-1.73, respectively). Hysterectomy, but not hysterectomy-BSO, was related to higher risk of thyroid cancer (HR, 1.38; 95% CI, 1.19-1.60). In contrast, hysterectomy (HR, 0.94; 95% CI, 0.90-0.98) and hysterectomy-BSO (HR, 0.92; 95% CI, 0.85-1.00) were associated with lower risk of breast cancer. We found no association between hysterectomy status and colorectal cancer.

CONCLUSIONS

The associations between hysterectomy and cancer varied by cancer type with increased risks for thyroid and kidney cancer, decreased risk for breast cancer, and no association for colorectal cancer.

IMPACT

As breast, colorectal, and gynecologic cancers comprise a sizeable proportion of all cancers in women, our results suggest that hysterectomy is unlikely to increase overall cancer risk; however, further research to understand the higher risk of thyroid and kidney cancer is warranted.

Uterine Fibroids Increase the Risk of Thyroid Cancer

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.