Risk of Breast Cancer in Females With Hypothyroidism: A Nationwide, Population-Based, Cohort Study

Thyroid Hormones Imbalances and Risk of Colorectal Cancer: a Meta-analysis

PURPOSE

No conclusive information is available about the association between hypothyroidism or hyperthyroidism and risk of colorectal cancer (CRC). We therefore aimed to summarize the findings of observational studies on the relation between hypothyroidism or hyperthyroidism and risk of CRC.

METHODS

A literature search was conducted using relevant keywords in online databases for appropriate publications through July 2023. Random effects model was used to calculate combined effect sizes (ESs) and 95% confidence intervals (CIs) to investigate relationship between hypothyroidism or hyperthyroidism and CRC risk.

RESULTS

Totally, we included 13 studies in the current systematic review and meta-analysis, with a total sample size of 33,557,450 individuals and 25,363 cases of CRC. Pooling 13 effect sizes revealed no significant association between hypothyroidism and risk of CRC (combined effect size: 1.13, 95% CI 0.87-1.48, P = 0.343). There was also no significant association between hyperthyroidism and risk of CRC (combined effect size: 1.09, 95% CI 0.75-1.57, P = 0.638). Additionally, there were significant associations between hypothyroidism and risk of CRC in the Far Eastern studies, between hyperthyroidism and risk of CRC in the Middle East, along with small sample size studies.

CONCLUSIONS

This meta-analysis did not reveal any association between hypothyroidism or hyperthyroidism and risk of CRC.

TRIAL REGISTRATION

PROSPERO CRD42022331089.

Association of thyroid autoimmunity with extra-thyroid diseases and the risk of mortality among adults: evidence from the NHANES

Background

Thyroid autoimmunity is one of the most prevalent autoimmune diseases. However, its association with extra-thyroid diseases and mortality risk in the general population remains uncertain. Our study aims to evaluate the association of thyroid autoimmunity with extra-thyroid disease and the risk of mortality.

Methods

A prospective cohort study was conducted using data from the National Health and Nutrition Examination Survey (NHANES) with participants from 2007-2008, 2009-2010, and 2011-2012, tracking their mortality until 2019. Associations between thyroid autoimmunity, which was defined as having positive thyroid peroxidase antibody (TPOAb) and/or thyroglobulin antibody (TgAb), and extra-thyroid disease including diabetes, hypertension, cardiovascular disease, chronic lung disease, arthritis, cancer and chronic renal disease and the risk of mortality were investigated.

Results

A total of 7431 participants were included in this study. Positive The prevalence of positive TgAb was 7.54%, and positive TPOAb prevalence was 11.48%. TgAb was significantly associated with diabetes (Model 1: OR=1.64, 95% CI:1.08-2.50; Model 2: OR=1.93, 95% CI: 1.21-3.08) and hypertension (Model 1: OR=0.67, 95% CI: 0.49-0.91; Model 2: OR=0.62, 95% CI: 0.44-0.88). TPOAb was associated with a lower prevalence of chronic lung disease (model 1: OR=0.71, 95% CI: 0.54-0.95; model 2: OR=0.71, 95% CI: 0.53-0.95). No associations were observed between TgAb, TPOAb and other extra-thyroid diseases. Neither TgAb nor TPOAb were associated with all-cause mortality or heart disease mortality.

Conclusion

TgAb was linked to a higher prevalence of diabetes and a lower prevalence of hypertension, while TPOAb was associated with a decreased prevalence of chronic lung disease. However, neither TgAb nor TPOAb posed a risk for all-cause mortality or heart disease mortality.

Prevalence of cancer in patients with hypothyroidism: Analysis using big data tools

OBJECTIVE

To evaluate the frequency of different types of cancer in patients diagnosed with hypothyroidism using big data methodology on the Savana Manager platform.

METHODS

An observational, retrospective study was carried out using electronic medical record (EMR) data from the Hospital Universitario Puerta de Hierro Majadahonda (Madrid). Information from the EMRs was extracted using artificial intelligence techniques and analysed using the Savana Manager v3.0 software. Searches were performed using the term "hypothyroidism" and the terms corresponding to the tumours analysed.

RESULTS

Of a total population of 506,749 patients, 23,570 (4.7%) were diagnosed with hypothyroidism. Patients with this diagnosis had a significantly higher frequency of cancer than that found in non-hypothyroid subjects (OR 2.09, 95% confidence interval [CI] 2.01-2.17). This higher frequency was found both in women (OR 1.99, 95% CI 1.90-2.08) and in men (OR 2.83, 95% CI 2.63-3.05). However, this higher frequency of cancer was not observed in hypothyroid patients older than 60 years (OR 0.97, 95% CI 0.92-1.02). Although the frequency of most of the neoplasms studied individually was higher in the population with hypothyroidism, we observed that hypothyroid patients over 60 years of age had a significant decrease in the frequency of prostate, lung, colorectal, and liver cancer.

CONCLUSION

Data from this hospital cohort suggest that there is a significant association between the diagnosis of hypothyroidism and cancer. However, this association is less evident in hypothyroid patients older than 60 years.

Older veterans associated with reduced risk of cancer: Retrospective nationwide matched cohort study in Taiwan

Importance

It remains unknown whether Taiwanese veterans have a lower risk of subsequent cancer compared with non-veterans.

Objective

To examine whether veterans are associated with reduced cancer risk.

Methods

From January 2004 to December 2017, this study included 957 veterans and 957 civilians who were propensity score (PS) matched by years of birth, sex, residence, index year, days in the hospital, frequency of outpatient visits, and relevant comorbidities at baseline. Multivariate Cox proportional hazards regression analysis was applied to compare the risks of cancer, overall and by subgroup, and mortality. All the participants were cancer free at the baseline.

Exposures

Veterans retrieved from Taiwan National Health Insurance Research Database (NHIRD).

Main outcome

Cancer extracted from the Registry for Catastrophic Illness Patients Database (RCIPD).

Results

Overall, 1,914 participants were included, and 957 veterans with a mean (SD) age of 75.9 (6.79) years and 946 men (98.9%). The mean follow-up was about 10.5 (±4.51) years. Cancer was recorded in 6.68% (N = 64) and 12.12% (N = 116) of veterans and non-veterans, respectively. Veterans were associated with decreased risk [adjusted hazard ratio (aHR), 0.57; 95% CI: 0.41-0.78; P < 0.001] of cancer compared with civilians after controlling for age, sex, urbanization, hypertension, diabetes, hyperlipidemia, cardiovascular event, COPD, asthma, chronic liver disease, alcohol-related illness, and Parkinson's disease. Cancer subgroup analyses verified this finding (HRs <1.0). The decreased incidence rate was predominantly for liver cancer (aHR, 0.18; 95% CI: 0.05-0.72; P < 0.05).

Conclusion

Taiwanese older veterans are associated with reduced overall cancer risk than individuals without veteran status.

The effect of thyroid dysfunction on breast cancer risk: an updated meta-analysis

In a previous systematic review and meta-analysis of studies reporting associations between hyper-/hypothyroidism and breast cancer incidence published through 29 January 2019, we identified a higher risk with diagnosed hyperthyroidism compared to euthyroidism, but no association with diagnosed hypothyroidism. This 2-year updated meta-analysis aims to investigate the role of menopause in this association and the dose-response relationship with blood levels of thyroid-stimulating hormone (TSH) and thyroid hormones. After the exclusion of studies with only mortality follow-up, with thyroid dysfunction evaluated as a cancer biomarker or after prior breast cancer diagnosis, we reviewed 25 studies that were published up to 01 December 2021 and identified in MEDLINE, the COCHRANE library, Embase, or Web of Science; of these, 9 were included in the previous meta-analysis. Risk estimates from 22 of the 25 studies were included in the meta-analysis and pooled using random-effects models. Compared to euthyroidism, hyperthyroidism and hypothyroidism diagnoses were associated with higher (pooled risk ratio (RR): 1.12, 95% CI: 1.06-1.18, 3829 exposed cases) and lower risks (RR = 0.93, 95% CI: 0.86-1.00, 5632 exposed cases) of breast cancer, respectively. The increased risk after hyperthyroidism was greater among postmenopausal women (RR = 1.19, 95% CI 1.09-1.30) and the decreased risk after hypothyroidism was more pronounced among premenopausal women (RR = 0.69, 95% CI 0.53-0.89). Among women with no prior history of thyroid disease, every 1 mIU/L increase in TSH level was associated with a 0.8% (95% CI > 0-1.5%) lower risk of breast cancer. In conclusion, this meta-analysis supports an association between thyroid hormone levels and breast cancer risk, which could be modified by menopausal status.

Malignant neoplasms in people with hypothyroidism in Spain: A population-based analysis

PURPOSE

The objective of this study was to determine the association between hypothyroidism and overall and site-specific cancer in Spanish population.

METHODS

A cross-sectional study was performed using the population-based database BDCAP (Base de Datos Clínicos de Atención Primaria, primary care clinical database) to analyze the relative risk of cancer in Spanish population with hypothyroidism.

RESULTS

In a total of 2,414,165 patients diagnosed with hypothyroidism in BDCAP in 2019, the relative risk (OR) of cancer, compared to the non-hypothyroid population, was 1.73 (1.72-1.74) (P<0.0001). The higher risk was observed in both men (OR 2.15 [2.13-2.17]; P<0.0001) and women (OR 1.67 [1.636-1.68]; P<0.0001). However, hypothyroid persons aged 65 years or older had a reduced risk of cancer (OR 0.98 [0.97-0.98]; P<0.0001). In addition, hypothyroid patients aged 65 or over showed a decreased risk of cancers of the bladder, colorectal, gastric, pancreatic and prostate. Socioeconomic characteristics such as income level, municipality size, country of birth and employment situation had limited influence on the association between hypothyroidism and cancer. However, hypothyroid patients receiving replacement therapy exhibited higher cancer risk compared with patients without treatment (OR 1.30 [1.28-1.31]; P<0.0001).

CONCLUSION

Spanish hypothyroid patients of both genders have a risk of overall cancer higher than that found in non-hypothyroid population. However, people over 65 years have a reduced risk of various malignancies. This peculiarity of hypothyroidism should be considered by the health authorities.