Prevalence of thyroid dysfunction in untreated cancer patients: a cross-sectional study

Is there an association between thyroid function tests and 18F FDG PET/CT parameters in untreated cancer patients?

Objectives: We aimed to investigate the association between the extent of disease, 18F FDG PET/CT parameters (SUVmax and the highest SUVmax) and thyroid function tests (TFT) (TSH, FT4, FT3, FT3/FT4 ratio, AntiTG, and AntiTPO) in untreated cancer patients. Material and Method: One hundred and seventy-nine patients who underwent FDG PET/CT for metabolic characterization and staging in our clinic between May 2020 and November 2020 were included in the study. Patients were divided into two groups as malignant and benign according to histopathology findings. Thyroid function tests were ordered from all patients at the time of PET/CT imaging. The association between the presence of local lymph node metastasis, distant metastases and thyroid function tests as well as the association between PET/CT parameters and thyroid function tests in benign and malignant groups were statistically analyzed. Results: Thyroid function tests did not exhibit a significant difference between patients with malignant and benign disease (p> 0.05). Univariate logistic regression analysis revealed that age, FT4 value, and the FT3/F4 ratio were significant parameters in predicting distant metastases. These parameters were also significant in predicting mortality. Multivariate logistic regression analysis showed that age was an independent prognostic factor predicting mortality. Conclusion: Thyroid function tests are not decisive in differentiating malignant and benign lesions. While no statistically significant correlation was observed between thyroid function tests and PET/CT parameters, univariate analyses revealed that especially FT4 and FT3/FT4 ratio were significant in predicting disease extent and mortality in malignant disease. Age was found to be an independent prognostic factor in predicting mortality.

Prevalence of Undiagnosed Hypothyroidism in Europe: A Systematic Review and Meta-Analysis

BACKGROUND

Patients with undiagnosed hypothyroidism are not treated for the disease and are at high risk of developing serious complications, with major impact on public health. There is a need to systematically review the available evidence on this topic.

OBJECTIVE

To identify the prevalence of undiagnosed hypothyroidism in Europe.

METHODS

A systematic review of the literature (Medline, EMBASE, and Cochrane Central) was performed to identify epidemiological studies on the prevalence of undiagnosed hypothyroidism among European populations published between January 2008 and April 2018. The Newcastle-Ottawa Scale was used to assess the methodological quality of the included studies. Random-effects meta-analyses were performed to pool estimates of proportions (with 95% confidence intervals [CIs]) of undiagnosed (1) subclinical, (2) overt, and (3) total hypothyroidism.

RESULTS

The search returned 15,565 citations (4,526 duplicates). Twenty papers were included in the study. Fourteen and 6 studies were of good and moderate methodological quality, respectively. The results of the meta-analyses were as follows for the prevalence of undiagnosed hypothyroidism: subclinical, 4.11% (95% CI 3.05-5.31%, I2 = 99.32%); overt, 0.65% (95% CI 0.38-0.99%, I2 = 96.67%); and total, 4.70% (95% CI 2.98-6.79%, I2 = 99.53%). According to the sensitivity analysis, the prevalence of hypothyroidism tends to be higher in female patients, in those aged ≥65 years, among studies with lower sample sizes, in those with thyroid-stimulating hormone levels <4.5 mIU/L, and in Eastern and Southern Europe.

CONCLUSIONS

The current evidence suggests that a considerable proportion of the European population has hypothyroidism, particularly subclinical hypothyroidism, which is undiagnosed. This issue deserves further investigation because of possible deleterious consequences for public health.

Thyroid Hormones and Cancer: A Comprehensive Review of Preclinical and Clinical Studies

Thyroid hormones take major part in normal growth, development and metabolism. Over a century of research has supported a relationship between thyroid hormones and the pathophysiology of various cancer types. In vitro studies as well as research in animal models demonstrated an effect of the thyroid hormones T3 and T4 on cancer proliferation, apoptosis, invasiveness and angiogenesis. Thyroid hormones mediate their effects on the cancer cell through several non-genomic pathways including activation of the plasma membrane receptor integrin αvβ3. Furthermore, cancer development and progression are affected by dysregulation of local bioavailability of thyroid hormones. Case-control and population-based studies provide conflicting results regarding the association between thyroid hormones and cancer. However, a large body of evidence suggests that subclinical and clinical hyperthyroidism increase the risk of several solid malignancies while hypothyroidism may reduce aggressiveness or delay the onset of cancer. Additional support is provided from studies in which dysregulation of the thyroid hormone axis secondary to cancer treatment or thyroid hormone supplementation was shown to affect cancer outcomes. Recent preclinical and clinical studies in various cancer types have further shown promising outcomes following chemical reduction of thyroid hormones or inhibition or their binding to the integrin receptor. This review provides a comprehensive overview of the preclinical and clinical research conducted so far.

Prevalence and Related Factors of Euthyroid Sick Syndrome in Children with Untreated Cancer According to Two Different Criteria

OBJECTIVE

In this study, we evaluated the frequency of euthyroid sick syndrome (ESS) among patients with childhood cancer and its association with the stage of disease, nutritional parameters and cytokines levels.

METHODS

Eighty newly diagnosed children were included in the study. ESS was assessed in two different ways. According to criteria 1 ESS was present if free triiodothyronine (fT3) was below the lower limit and free thyroxine was within the normal or low limits, thyroid-stimulating hormone (TSH) was in the normal range. According to criteria 2, in addition to the above, it was required that reverse triiodothyronine (rT3) be performed and was higher than normal limits.

RESULTS

Three of our pediatric patients had subclinical hypothyroidism and two had subclinical hyperthyroidism. Out of 75 patients, ESS was identified in 14 (17.3%) according to criteria 1 and in eight (10.6%) according to criteria 2. Only fT3 levels were significantly different in the ESS (+) and ESS (-) groups (p<0.05) according to criteria 1. A significantly negative correlation between interleukin (IL)-6 and fT3 was found, according to both sets of criteria. tumor necrosis factor alpha was negatively correlated with fT3 levels only in the criteria 1 group. There were no correlations between IL-1β and fT3, free thyroxine, rT3 and TSH levels.

CONCLUSION

ESS may occur in childhood cancer and thyroid function testing should be performed routinely when cancer is diagnosed.

Lower TSH and higher free thyroxine predict incidence of prostate but not breast, colorectal or lung cancer

CONTEXT

Thyroid hormones modulate proliferative, metabolic and angiogenic pathways. However few studies have examined associations of thyroid hormones with cancer risk.

OBJECTIVES

To explore associations of thyrotropin (TSH), free thyroxine (FT4) and anti-thyroperoxidase antibodies (TPOAb) with the incidence of all (non-skin) cancers and specific common cancers.

DESIGN AND SETTING

A prospective cohort study of a community-dwelling population aged 25-84 years in Western Australia.

MAIN OUTCOME MEASURES

Archived sera from 3649 participants in the 1994/1995 Busselton Health Survey were assayed for TSH, FT4 and TPOAb. Cancer outcomes until 30 June 2014 were ascertained using data linkage. Longitudinal analyses were performed using Cox proportional hazards regression.

RESULTS

During 20-year follow-up, 600 participants were diagnosed with non-skin cancer, including 126, 100, 103 and 41 prostate, breast, colorectal and lung cancers respectively. Higher TSH was associated with a lower risk of prostate cancer after adjusting for potential confounders, with a 30% lower risk for every 1 IU/L increase in TSH (adjusted hazard ratio (HR): 0.70, 95% confidence interval (CI): 0.55-0.90, P = 0.005). Similarly, higher FT4 was associated with an increased risk of prostate cancer (adjusted HR: 1.11 per 1 pmol/L increase, 95% CI: 1.03-1.19, P = 0.009). There were no associations of TSH, FT4 or TPOAb with all non-skin cancer events combined, or with breast, colorectal or lung cancer.

CONCLUSION

In a community-dwelling population, lower TSH and higher FT4 were associated with an increased risk of prostate cancer. Further studies are required to assess if thyroid function is a biomarker or risk factor for prostate cancer.

Thyroid hormones and mortality risk in euthyroid individuals: the Kangbuk Samsung health study

CONTEXT

Hyperthyroidism and hypothyroidism, both overt and subclinical, are associated with all-cause and cardiovascular mortality. The association between thyroid hormones and mortality in euthyroid individuals, however, is unclear.

OBJECTIVE

To examine the prospective association between thyroid hormones levels within normal ranges and mortality endpoints.

SETTING AND DESIGN

A prospective cohort study of 212 456 middle-aged South Korean men and women who had normal thyroid hormone levels and no history of thyroid disease at baseline from January 1, 2002 to December 31, 2009. Free T4 (FT4), free T3 (FT3), and TSH levels were measured by RIA. Vital status and cause of death ascertainment were based on linkage to the National Death Index death certificate records.

RESULTS

After a median follow-up of 4.3 years, 730 participants died (335 deaths from cancer and 112 cardiovascular-related deaths). FT4 was inversely associated with all-cause mortality (HR = 0.77, 95% confidence interval 0.63-0.95, comparing the highest vs lowest quartile of FT4; P for linear trend = .01), and FT3 was inversely associated cancer mortality (HR = 0.62, 95% confidence interval 0.45-0.85; P for linear trend = .001). TSH was not associated with mortality endpoints.

CONCLUSIONS

In a large cohort of euthyroid men and women, FT4 and FT3 levels within the normal range were inversely associated with the risk of all-cause mortality and cancer mortality, particularly liver cancer mortality.

Type and extent of somatic morbidity before and after the diagnosis of hypothyroidism. a nationwide register study

BACKGROUND

Hypothyroidism has been linked with an increased risk of other morbidities, such as cardiovascular diseases and diabetes mellitus. However, the temporal relationship between these diseases and the diagnosis of hypothyroidism is not well illuminated. Such information may provide insight into causal relationships between hypothyroidism and other morbidities.

AIM

To investigate the type and extent of somatic morbidity before and after a diagnosis of hypothyroidism.

METHODS

Observational cohort study. From official Danish health registers, 2822 hypothyroid singletons were identified and matched 1:4 with non-hypothyroid controls and observed over a mean period of 6 years. Frequency of different morbidities was obtained by person-to-person linking in the registers. Logistic and Cox regression models were used to assess the risk of morbidity before and after the diagnosis of hypothyroidism, respectively.

RESULTS

Prior to the diagnosis of hypothyroidism there was a significantly increased risk of being diagnosed with cardiovascular diseases (odds ratio (OR) 1.37; 95% confidence interval (CI): 1.19-1.58), lung diseases (OR 1.25; 95% CI: 1.13-1.39), diabetes mellitus (OR 1.92; 95% CI: 1.61-2.29), as well as malignant diseases (OR 1.24; 95% CI: 1.06-1.45). Following the diagnosis of hypothyroidism there was a significantly increased risk of being diagnosed with cardiovascular diseases (hazard ratio (HR) 1.36; 95% CI: 1.15-1.60); lung diseases (HR 1.51; 95% CI: 1.30-1.75); and diabetes mellitus (HR 1.40; 95% CI: 1.11-1.77).

CONCLUSIONS

Prior to the diagnosis of hypothyroidism there is an excess risk of being diagnosed with cardiovascular diseases, lung diseases, diabetes mellitus, and malignant diseases. Following the diagnosis of hypothyroidism we demonstrate an increased frequency of cardiovascular diseases, lung diseases, and diabetes mellitus.

Morbidity before and after the diagnosis of hyperthyroidism: a nationwide register-based study

BACKGROUND

Hyperthyroidism has been linked with different morbidities, like atrial fibrillation, stroke and diabetes mellitus. However, our knowledge regarding the extent and temporal relation between hyperthyroidism and other diseases is fragmented. Here, we aimed at evaluating various morbidities before and after the diagnosis of hyperthyroidism.

METHODS

Observational cohort study. From nationwide Danish health registers 2631 hyperthyroid singletons and 375 twin pairs discordant for hyperthyroidism were identified and followed for an average of 6 years (range 0-13). Data on the occurrence of cardiovascular diseases, lung diseases, diabetes mellitus, rheumatic diseases and malignant diseases was obtained by person-to-person record linkage with the National Danish Patient Register and/or the Danish National Prescription Registry (lung diseases and diabetes mellitus). Logistic and Cox regression models were used to assess the risk of morbidity before and after the diagnosis of hyperthyroidism, respectively. All Cox regression analyses were adjusted for the degree of co-morbidity preceding the diagnosis of hyperthyroidism, using the Charlson score.

RESULTS

Hyperthyroid individuals had a significantly higher risk of being diagnosed with cardiovascular diseases (odds ratio (OR) 1.65; 95% confidence interval (CI): 1.45-1.87), lung diseases (OR 1.53; 95% CI: 1.29-1.60), and diabetes mellitus (OR 1.43, 95% CI: 1.20-1.72), but not with malignant diseases (OR 1.16, 95% CI: 0.99-1.36) prior to the diagnosis of hyperthyroidism. After the diagnosis of hyperthyroidism, subjects had a significantly higher risk of being diagnosed with cardiovascular diseases (hazard ratio (HR) 1.34; 95% CI: 1.15-1.56), lung diseases (HR 1.28; 95% CI: 1.10-1.49), and diabetes mellitus (HR 1.46; 95% CI: 1.16-1.84), but not with rheumatic diseases (HR 1.39, 95% CI: 0.92-2.09) or malignant diseases (HR 1.18, 95% CI 0.97-1.42).

CONCLUSIONS

We demonstrate a significantly increased burden of morbidity, both before and after the diagnosis of hyperthyroidism.