Papillary thyroid cancer, although strongly associated with lymphocytic infiltration on histology, is only weakly predicted by serum thyroid auto-antibodies in patients with nodular thyroid diseases

Geographic variation in the association between Hashimoto's thyroiditis and Papillary thyroid carcinoma, a meta-analysis

PURPOSE

The association between papillary thyroid cancer (PTC) and Hashimoto's thyroiditis (HT) remains a matter of debate. Several genetic and environmental factors have been found to influence this association. Because of the variation in these factors among different populations, we conducted a country- and region-based meta-analysis to examine whether the geographic area influences this association.

METHODS

We searched PubMed and Web of Science databases for original articles that investigated the association between HT and PTC from February 1955 to February 28, 2023. The included studies were stratified according to their country and region of origin. Various subgroup analyses were conducted. The primary outcome was the pooled relative risk (RR) and its 95% confidence interval (CI) for each region and country.

RESULTS

Forty-six studies including a total of 93,970 participants met our inclusion criteria. They originated from 16 countries distributed in five regions. Significant variation was found among countries but not among regions. Upon analysis of all 46 included studies, countries were classified based on their RR and its 95% CI. Excluding countries with pooled sample sizes <500, Sri Lanka (RR 4.23, 95% CI 2.91-6.14), Poland (RR 3.16, 95% CI 2.79-3.57) and Japan (2.68, 2.14-3.36) showed the strongest association between HT and PTC while Greece (RR 1.06, 95% CI 1.00-1.13), Spain (RR 0.70, 95% CI 0.23-2.11), and Jordan (0.62, 0.32-1.32) showed no significant association.

CONCLUSION

Our findings revealed a variation in the association between HT and PTC among countries but not among regions. The country-to-country variation could be due to certain genetic and/or environmental factors subject to geographic variation that influence this association. These findings may help guide health policies aiming to mitigate the risk of PTC in the HT population by helping identify high-risk and low-risk countries.

Classification of Thyroid Nodules with Stacked Denoising Sparse Autoencoder

PURPOSE

Several commercial tests have been used for the classification of indeterminate thyroid nodules in cytology. However, the geographic inconvenience and high cost confine their widespread use. This study aims to develop a classifier for conveniently clinical utility.

METHODS

Gene expression data of thyroid nodule tissues were collected from three public databases. Immune-related genes were used to construct the classifier with stacked denoising sparse autoencoder.

RESULTS

The classifier performed well in discriminating malignant and benign thyroid nodules, with an area under the curve of 0.785 [0.638-0.931], accuracy of 92.9% [92.7-93.0%], sensitivity of 98.6% [95.9-101.3%], specificity of 58.3% [30.4-86.2%], positive likelihood ratio of 2.367 [1.211-4.625], and negative likelihood ratio of 0.024 [0.003-0.177]. In the cancer prevalence range of 20-40% for indeterminate thyroid nodules in cytology, the range of negative predictive value of this classifier was 37-61%, and the range of positive predictive value was 98-99%.

CONCLUSION

The classifier developed in this study has the superb discriminative ability for thyroid nodules. However, it needs validation in cytologically indeterminate thyroid nodules before clinical use.

Thyroid Carcinoma Coexisting with Hashimoto's Thyreoiditis: Clinicopathological and Molecular Characteristics Clue up Pathogenesis

Thyroid cancer (TC) coexisting with Hashimoto’s thyroiditis (HT) presents with several characteristic features including multifocality and lower clinical stages compared to de novo carcinomas but its exact biology is still not understood. We reexamined clinico-pathological and molecular correlations between Hashimoto’s thyroditis and papillary thyroid cancer. A total of 262 patients with TC was evaluated who underwent thyroidectomy at the Surgical Department of the University of Debrecen. Clinical data, histology and molecular data were evaluated. Our cohort included 43 patients (16.4%) with (5 male, 38 female) and 219 (83.6%) patients without coexisting HT (48 male, 171 female). Hashimoto’s thyroiditis related thyroid cancer presented predominantly (93.0% of the cases) with the papillary histological type. Multifocality was observed more frequently with coexisting HT (16/40; 40.0%) compared to cases uninvolved (45/190; 23.7%)(p = 0.034). In contrast, lymphatic metastasis (pN1) with a significantly reduced frequency in patients with HT (4/11; 36.4%) then without HT (34/41 pN1; 82.9%)(p = 0.002). BRAF V600E mutation could be demonstrated at significantly lower rates in cases of PTC + HT (32.1 vs 60.7%, p < 0.005). High incidence, multifocality and papillary morphology strongly support a causal relation between TC and preexisting Hashimoto’s thyroiditis, the latter to be considered as a preneoplastic condition promoting thyroid carcinogenesis.

Influence of Hashimoto Thyroiditis on the Development of Thyroid Nodules and Cancer in Children and Adolescents

It is unclear whether patients with Hashimoto thyroiditis (HT) are predisposed to develop thyroid nodules and/or thyroid cancer. The objective of our study was therefore to assess the prevalence of thyroid nodules and/or cancer in patients with HT and to look for possible prognostic factors. A retrospective survey of 904 children/adolescents with HT (709 females, 195 males) regularly followed in nine Italian centers of pediatric endocrinology was performed. Median period of follow-up was 4.5 years (1.2 to 12.8 years). We evaluated free T4, TSH, thyroid peroxidase antibody (TPOAb), thyroglobulin antibodies, and thyroid ultrasound yearly. One hundred seventy-four nodules were detected, with an annual incidence rate of 3.5%. Ten nodules were malignant (8 papillary and 2 papillary follicular variant), giving a 5.7% prevalence of cancer among patients with nodules. The severity of hypoechogenity at ultrasound, TPOAb, and free T4 serum concentrations were predictive for the appearance of new nodules. Furthermore, a positive correlation was observed between TPOAb titer and the development of thyroid cancer. In conclusion, HT seems to influence the development of thyroid nodules, but not cancer in children and adolescents.

Gender-specific correlation of intranodular chronic lymphocytic thyroiditis with thyroid nodule size, echogenicity, and histologically-verified cytological class of malignancy risk

No data are available on the cytologically and histologically demonstrated presence of intranodular chronic lymphocytic thyroiditis (ICLT) and on the ICLT relationship with thyroid nodule characteristics such as size, echotexture and nature (benign or malignant). We wished to fill this gap by analyzing data in a gender-specific fashion. We studied 408 thyroid nodules from 408 consecutive persons (325 females and 83 males). Nodules were isoechoic (n = 268) or hypoechoic (n = 140), ICLT +ve (n = 113 [27.7%]) or ICLT -ve (n = 295), cytologically low-risk (n = 197) or high-risk (n = 211), histologically benign (n = 263) or malignant (n = 145). ICLT prevailed in females (97/113) and in hypoechoic nodules (58/140 [41.4%] vs 55/268 [20.5%], P < 0.0001). Compared to males, females had (i) smaller nodules (18.5 ± 9.4 vs 23.3 ± 13.4 mm, P = 0.0002), a difference due to the isoechoic nodules (21.1 ± 9.8 vs 26.6 ± 14.1 mm, P = 0.0006), (ii) lower rates of high-risk nodules (161/325 [49.5%] vs 50/83 [60.2%], P = 0.082) and malignant nodules (110/325 [33.8%] vs 35/83 [42.2%] P = 0.16). ICLT +ve nodules were smaller than the ICLT -ve ones (15.4 ± 6.9 vs 20.9 ± 11.2 mm, P < 0.0001), a difference due to the isoechoic nodules (17.5 ± 6.5 vs 23.6 ± 11.7 mm, P = 0.0003). The smallest nodules were hypoechoic, cancerous and ICLT +ve nodules in males (9.5 ± 4.0 mm); the largest were isoechoic, cytologically risky and ICLT -ve in males (29.1 ± 13.2 mm). Compared to ICLT -ve nodules, malignancy prevailed in ICLT +ve nodules (55/113 [48.7%] vs 90/295 [30.5%], P = 0.0006), both in hypoechoic (37/58 [63.8%] vs 41/82 [50.0%]) and isoechoic nodules (18/55 [32.7%] vs 49/213 [23.0%]). ICLT +ve hypoechoic nodules of females and ICLT -ve hypoechoic nodules of males had the greatest rate of malignancy (67% both), while ICLT -ve isoechoic nodules of females had the lowest (19%). In conclusion, presence/absence of ICLT is associated with some sexually dimorphic characteristics of thyroid nodules. Adding the specification of ICLT positivity/negativity in cytological reports may help improving the risk of malignancy at least in some groups of thyroid nodules.

High prevalence of papillary thyroid carcinoma in nodular Hashimoto's thyroiditis at the first diagnosis and during the follow-up

BACKGROUND

The association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) remains to be elucidated.

MATERIALS AND METHODS

A total of 484 HT patients were retrospectively subdivided into two groups: 243 without thyroid nodules, TNs (HTN-) and 241 with TNs (HTN+). Fine-needle aspiration cytology was available in 152 HTN+ patients. This group was compared to a group of 161 patients with nodular goiter (NG) without HT. Finally, 70 HTN+ and 37 NG patients underwent surgery.

RESULTS

A very high prevalence of suspicious/malignant cytology (Thy 4-5) at the first diagnosis (38/124; 31%) and during the follow-up (6/28; 22%) was found in HTN+ group. In HTN- group, 22/130 (17%) patients developed TN, but none showed malignant features during the follow-up. HTN+ patients had higher prevalence of Thy 4-5 (44/152 = 28.9%) compared to NG patients (12/161 = 7.4%, p < 0.0001). Increased independent odds ratio (OR) for malignancy was conferred by serum TSH > 1.0 μUI/ml, [OR 1.93, 95% confidence interval (CI) 1.41-2.64, p < 0.0001], male sex (OR 3.44, CI 1.48-8.02, p = 0.004) and HT (OR 3.14; CI 1.08-9.31, p < 0.05). Malignant histology (mostly PTC) was confirmed higher in HTN+ (48/70, 68.6%) compared to NG (15/37, 40.5%; p < 0.05). Higher prevalence of extrathyroidal infiltration (24/48, 50%) and vascular invasion (25/48, 52%) was found in HTN+ vs NG (2/15, 1.3% p < 0.01), (3/16, 1.8% p < 0.05), respectively.

CONCLUSIONS

This study confirms higher prevalence of suspicious/malignant cytology and PTC at histology in nodular HT compared to NG, without evidence of malignancy in non-nodular HT patients during the follow-up.

Thyroid functional parameters and correlative autoantibodies as prognostic factors for differentiated thyroid cancers

To evaluate the effect of preoperative thyroid functional parameters and thyroid autoantibodies on aggressive clinicopathologic features and lymph node metastasis (LNM) of differentiated thyroid cancer patients. Four hundred twenty consecutive patients with initial surgery were enrolled from July 2010 to July 2015. The associations between aggressive clinicopathologic and LNM factors and thyroid functional & autoantibodies parameters were analyzed. Higher levels of TSH, TGAb or TMAb were found in patients with tumor size≥1 cm (all P<0.05), especially when TSH≥2.5 ulU/ml (P=0.03) and TGAb≥1 (P=0.01). Higher levels of TSH and TGAb and lower levels of T3 and T4 were found in patients with capsular invasion (all P<0.05), particularly when TSH≥2.5ulU/ml (P=0.03) and TGAb≥1 (P=0.005). The patients with multifocality had higher TAbs level (TAbs>1). Higher level of TSH was also found in patients with central LNM (P=0.001) and lateral LNM (P=0.002), especially with TSH≥2.5ulU/ml (P=0.003 and P=0.03). TGAb level was also found higher in patients with central LNM (P=0.02) and lateral LNM (P=0.01), especially with TGAb≥1 (P<0.05 and P=0.01). Higher level of TMAb was found in patients with lateral LNM (P<0.05). Moreover, multivariable analysis revealed that only TGAb was an independently predictive factor for primary tumor size≥1cm (P=0.01); and TSH level (P=0.01) and TGAb≥1 (P<0.05) were associated independently with central LNM. Thus, TSH level and TGAb≥1 were significantly independent predictors for central LNM, and might help make the decision of central neck dissection.

Positive Antithyroid Antibodies and Nonsuppressed TSH Are Associated with Thyroid Cancer: A Retrospective Cross-Sectional Study

The relationship between Hashimoto's thyroiditis (HT) and thyroid cancer (TC) is a controversial topic; it remains unclear if HT acts as a risk factor of TC. The aim of our study was to compare the presence of HT and thyroid function in patients with TC and benign nodules. We analyzed 2571 patients after fine needle aspiration biopsy of thyroid nodule. Totally, 91 patients with primary TC and 182 sex- and age-matched controls were included. Positive antithyroid peroxidase (anti-TPO) and antithyroglobulin (anti-Tg) antibodies were associated with TC (anti-TPO 44% in TC vs. 27% in controls, P = 0.005, anti-TG 35% in TC group vs. 21% in controls, P = 0.018), and the TC group had significantly higher TSH (median 1.88 mIU/l vs. 1.21 mIU/l, P < 0.001). Using multiple logistic regression, positive anti-TPO was identified as an independent risk factor (OR 2.21, P = 0.018), while spontaneously suppressed TSH < 0.5 mIU/l was a protective factor (OR 0.3, P = 0.01) against TC. In conclusion, nodules in subjects with positive antithyroid antibodies could be considered to have a higher risk of malignancy. However, based on our results, it is not possible to declare that TC is triggered by HT.

Coexistence of Papillary Thyroid Carcinoma With Thyroid MALT Lymphoma in a Patient With Hashimoto's Thyroiditis: A Clinical Case Report

Papillary thyroid carcinoma (PTC) is the most common type of thyroid neoplasias; however, primary thyroid gland lymphoma (PTL) is uncommon and their simultaneous occurrence is very rare.Herein, we reported a 25-year-old female patient with Hashimoto's thyroiditis (HT), who developed a small goiter with a palpable 1.2-cm nodule in the right lobe. A fine-needle aspiration (FNA) biopsy revealed atypical follicular epithelial cells and lymphoid cells in a background of lymphocytic thyroiditis. A total thyroidectomy was performed. The pathology showed multicentric papillary thyroid carcinoma, concomitant thyroid mucosa-associated lymphoid tissue (MALT) lymphoma, and Hashimoto's thyroiditis. Postoperatively, he received chemotherapy and radioactive iodine ablation treatment. Nowadays the thyroglobulin of the patient is undetectable, without recurrences at 2 years of follow-up.It is concluded that the PTC and MALT lymphoma can exist concomitantly, especially in patients with HT. For the diagnostic workup and optional management of this rare coexistence, a multidisciplinary approach and close surveillance are needed.

Iodine, thyroid autoimmunity and cancer

This review focuses on two different topics: (a) iodine and autoimmune thyroid disease (AITD) and (b) AITD and papillary thyroid carcinoma (PTC). Iodine intake modifies the expression of thyroid diseases and has been associated with induction of AITD. Thyroglobulin (Tg) is an important target in iodine-induced autoimmune response due to post-translational modifications of iodinated Tg, as suggested in animal models. We have shown that the unmasking of a cryptic epitope on Tg contributes to iodine-induced thyroid autoimmunity in humans. The relationship between AITD and PTC has been suggested in many studies. The presence of two different mechanisms has been hypothesized, one typical of AITD and the other of an immune reaction to PTC. We have shown that in AITD, the pattern of Tg recognition by anti-Tg antibodies (TgAb) is 'restricted' to the immunodominant regions of Tg, while in patients with non-AITD, such as nodular goiter and PTC devoid of thyroid lymphocytic infiltration at histology, TgAb show a less restricted epitopic pattern and bind also to other regions of Tg. Thyroid function may also affect the frequency of PTC, the risk of cancer increasing with serum TSH levels. We have shown that this mechanism, rather than thyroiditis per se, plays a major role in the association of PTC with Hashimoto's thyroiditis, as a consequence of the autoimmune process leading to a progressive increase of serum TSH in these patients.

Peroxisome Proliferator-Activated Receptor- γ in Thyroid Autoimmunity

Peroxisome proliferator-activated receptor- (PPAR-) γ expression has been shown in thyroid tissue from patients with thyroiditis or Graves' disease and furthermore in the orbital tissue of patients with Graves' ophthalmopathy (GO), such as in extraocular muscle cells. An increasing body of evidence shows the importance of the (C-X-C motif) receptor 3 (CXCR3) and cognate chemokines (C-X-C motif) ligand (CXCL)9, CXCL10, and CXCL11, in the T helper 1 immune response and in inflammatory diseases such as thyroid autoimmune disorders. PPAR-γ agonists show a strong inhibitory effect on the expression and release of CXCR3 chemokines, in vitro, in various kinds of cells, such as thyrocytes, and in orbital fibroblasts, preadipocytes, and myoblasts from patients with GO. Recently, it has been demonstrated that rosiglitazone is involved in a higher risk of heart failure, stroke, and all-cause mortality in old patients. On the contrary, pioglitazone has not shown these effects until now; this favors pioglitazone for a possible use in patients with thyroid autoimmunity. However, further studies are ongoing to explore the use of new PPAR-γ agonists in the treatment of thyroid autoimmune disorders.

Biomarkers of thyroid function and autoimmunity for predicting high-risk groups of thyroid cancer: a nested case-control study

Background

A remarkable increase in the number of thyroid cancer cases has been reported in recent years; however, the markers to predict high-risk groups have not been fully established.

Methods

We conducted a case–control study (257 cases and 257 controls) that was nested in the Cancer Screenee Cohort Study between August 2002 and December 2010; the mean follow-up time for this study was 3.1 ± 2.2 years. The levels of total triiodothyronine (TT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), anti-thyroperoxidase antibody (TPOAb), and anti-thyroglobulin antibody (TgAb) were measured using samples with pre-diagnostic status. Logistic regression models were used to examine the association between thyroid function/autoimmunity and thyroid cancer risk.

Results

When the markers were categorized by the tertile distributions of the control group, the highest tertile of FT4 (OR = 1.73, 95% CI = 1.11 - 2.69) and the middle tertile of TSH (OR = 1.77, 95% CI = 1.14 - 2.74) were associated with an increased risk of thyroid cancer by multivariate analyses. In addition, an elevated risk for thyroid cancer was found in subjects with TPOAb levels above 30 IU/mL (OR = 8.47, 95% CI = 5.39 - 13.33 for 30–60 IU/mL and OR = 4.48, 95% CI = 2.59 - 7.76 for ≥60 IU/mL). Stratified analyses indicated that some of these associations differed by sex, BMI, smoking status, and the duration of follow-up.

Conclusions

This study demonstrated that the levels of biomarkers of thyroid function/autoimmunity, particularly the presence of TPOAb, might be used as diagnostic markers for predicting thyroid cancer risk. Our findings suggest that careful monitoring of thyroid biomarkers may be helpful for identifying Korean populations at high-risk for thyroid cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-873) contains supplementary material, which is available to authorized users.

Nodules in autoimmune thyroiditis are associated with increased risk of thyroid cancer in surgical series but not in cytological series: evidence for selection bias

BACKGROUND

The association of thyroid cancer and autoimmune thyroiditis (AIT) has been widely addressed, with conflicting results in surgical and cytological series, likely affected by selection bias.

OBJECTIVE

The objective of the study was to evaluate the association between the cytological features suggestive or indicative of malignancy and AIT in 2504 consecutive patients (2029 females and 475 males, mean age 58.3 ± 14.1 y) undergoing fine-needle aspiration cytology for thyroid nodules.

PATIENTS

Based on the clinical diagnosis, patients were divided into four groups: AIT with nodules (N-AIT, 14.9%); nodular Graves disease (N-GD, 2.8%); nodular goiter and negative thyroid antibodies (NGAb-, 68.4%); and nodular goiter with positive thyroid antibodies (NGAb+, 13.9%).

RESULTS

The prevalence of patients with cytological features suggestive (Thy4) or indicative of malignancy (Thy5) was 4.5 % in the N-AIT group, not different compared with the other groups (N-GD, 5.6%; NGAb-, 5.0%; NGAb+, 4.3%). No difference was also found in the other categories (Thy2 and Thy3). When the same analysis was performed in the subgroup of patients (14.3%) with a histological confirmation, we found that the prevalence of differentiated thyroid cancer was significantly higher (P = .01) in the N-AIT group (67.8%) compared with the other groups (N-GD, 40.0%; NGAb-, 37.2%; NGAb+, 36.9%).

CONCLUSIONS

The results of our cytological series do not support a link between N-AIT and thyroid cancer. The association between cancer and N-AIT found in the histology-based series is likely due to a selection bias represented by the fact that the prevalent indication for surgery in the N-AIT group was suspicious cytology (60.7% of patients) more frequently than in the other groups.

Coexistence of thyroglobulin antibodies and thyroid peroxidase antibodies correlates with elevated thyroid-stimulating hormone level and advanced tumor stage of papillary thyroid cancer

The correlation between thyroglobulin antibodies (TgAb) or thyroid peroxidase antibodies (TPOAb) and papillary thyroid cancer (PTC) remains controversial. This histological study aimed to explore the correlation between thyroid autoantibodies (TAb), thyroid-stimulating hormone (TSH), and PTC in patients with thyroid nodules (TN). This was a retrospective study. 2,132 non-autoimmune thyroid diseases (AITD) patients who underwent thyroidectomy were subdivided into: TgAb or TPOAb single positive (TgAb+ or TPOAb+) TN group; TgAb and TPOAb double positive or negative (TAb+ or TAb-) TN group. PTC patients showed a higher rate of TAb+ TN (10.24 vs. 4.89 %; P = 0.000) and a higher TSH level (1.83 ± 0.07 vs. 1.39 ± 0.03 mIU/L; P = 0.000) than patients with benign nodules. TAb+ TN patients showed a higher TSH level and PTC frequency than those with TAb- TN (1.91 ± 0.17 vs. 1.47 ± 0.03 mIU/L; P = 0.011) (41.35 vs. 22.08 %; P = 0.000). In PTC, TAb+ TN patients showed a higher TSH level (2.57 ± 0.35 vs. 1.79 ± 0.07 mIU/L; P = 0.032), a greater frequency of lymph node metastasis (52.73 vs. 36.51 %, P = 0.026), and a lower micro-PTC frequency (16.36 vs. 39.51 %; P = 0.001) than TAb- TN patients. PTC was correlated with TgAb+ TN (OR = 1.921, CI 1.431-2.580; P = 0.000), TPOAb+ TN (OR = 1.945, CI 1.195-3.165; P = 0.007), TAb+ TN (OR = 2.393, CI 1.635-3.501; P = 0.000), and serum TSH >1.35 mIU/L (OR = 1.742, CI 1.089-2.786; P = 0.021). Serum positive TgAb or TPOAb is an independent predictor for PTC regardless of AITD. The coexistence of TgAb and TPOAb confers a greater risk for PTC than isolated positive TgAb or TPOAb, and is correlated with elevated TSH level and advanced PTC stage.

Papillary Thyroid Cancer and Hashimoto's Thyroiditis: An Association Less Understood

Hashimoto's thyroiditis (HT), part of the spectrum of autoimmune thyroid diseases is a major cause of thyroid hypofunction worldwide. Papillary thyroid carcinoma (PTC), the most prevalent of all thyroid carcinomas has been associated with HT. Literature on this association are based on preoperative FNA or post thyroidectomy histopathology reports, which are subject to potential biases. Molecular, hormonal and histopathalogical basis of this association has been hypothesized, however a definite causal association has not been proved till date. This review aims to study the basis of this association and clinical features and management of HT concurrent with PTC. There are no distinctive clinical or radiological features that categorically differentiates HT concurrent with PTC from PTC or which can pick up a nodule harboring PTC in setting of HT. Smaller nodule size and radiological features like hypoechogenecity; hyper vascularity and calcification in a clinical setting of hypothyroidism have a higher odds ratio for malignancy and merit further investigations. PTC associated with HT has been seen to be less aggressive with earlier presentation with lesser chances of extra thyroidal extension and lymph nodal metastasis. The management and follow up of PTC in HT is no different from that of PTC alone. The prognosis of PTC concurrent with HT is better compared to age and stage matched PTC in terms of lower recurrence and disease free and overall survival.

Hashimoto's thyroiditis pathology and risk for thyroid cancer

BACKGROUND

Hashimoto's thyroiditis (HT) has been found to coexist with differentiated thyroid cancer (DTC) in surgical specimens, but an association between the two conditions has been discounted by the medical literature. Therefore, we performed this study to determine any potential relationship between HT and the risk of developing DTC.

METHODS

We collected data for thyrotropin (TSH), thyroxine (T4), thyroid peroxidase antibody (TPO-Ab) titers, surgical pathology, and weight-based levothyroxine (LT4) replacement dose for patients who were referred for thyroid surgery. Patients with HT at final pathology were studied further. To estimate thyroid function, patients with preoperative hypothyroid HT (Hypo-HT) were divided into three equal groups based on their LT4 replacement: LT4-Low (<0.90 μg/kg), LT4-Mid (0.90-1.43 μg/kg), and LT4-High (>1.43 μg/kg). A group of preoperatively euthyroid (Euth-HT) patients but with HT by pathology was also studied. All subjects were also grouped based on their TPO-Ab titer in TPO-high (titer >1:1000) or TPO-low/negative (titer <1:1000 or undetectable) groups. The relationship of HT and DTC was studied extensively.

RESULTS

Of 2811 subjects, 582 had HT on surgical pathology, 365 of whom were Euth-HT preoperatively. DTC was present in 47.9% of the Euth-HT, in 59.7% of LT4-Low, 29.8% of LT4-Mid, and 27.9% of LT4-High groups. The relative risk (RR) for DTC was significantly elevated for the Euth-HT and LT4-Low groups (p<0.001), but not for the LT4-Mid or LT4-High replacement dose groups. TPO-low/negative status conferred an increased RR in the Euth-HT and LT4-Low replacement dose groups (p<0.001 both), while TPO-high status decreased it in Euth-HT group (p<0.05) and made it nonsignificant in the LT4-Low group.

CONCLUSIONS

HT pathology increases the risk for DTC only in euthyroid subjects and those with partially functional thyroid glands (LT4-Low) but not in fully hypothyroid HT (LT4-Mid and LT4-High). High TPO-Ab titers appear to protect against DTC in patients with HT.

Selenite supplementation in euthyroid subjects with thyroid peroxidase antibodies

CONTEXT

Euthyroid thyroid peroxidase (TPO-Ab)-positive subjects are at risk for progression to subclinical and overt autoimmune hypothyroidism. Previous studies have shown a decrease in TPO-Ab and improvement of quality-of-life (QoL) in L-T4-treated hypothyroid patients upon selenium supplementation.

OBJECTIVES

To evaluate in euthyroid TPO-Ab-positive women without thyroid medication whether selenite decreases TPO-Ab and improves QoL.

DESIGN

Randomized, placebo-controlled, double-blind study.

PATIENTS AND METHODS

Euthyroid (TSH 0·5-5·0 mU/l, FT4 10-23 pm) women with TPO-Ab ≥ 100 kU/l were randomized to receive 200 mcg sodium selenite daily (n = 30) or placebo (n = 31) for 6 months. TSH, FT4, TPO-Ab, selenium (Se), selenoprotein P (SePP) and QoL were measured at baseline, 3, 6 and 9 months.

RESULTS

There were no differences in baseline characteristics between the Se group and the placebo group. During selenite supplementation, serum Se and SePP did not change in the placebo group, but increased in the Se group. TPO-Ab and TSH did not change significantly in any group. TPO-Ab in the Se group were 895 (130-6800) at baseline, 1360 (60-7050) kU/l at 6 months, in the placebo group 1090 (120-9200) and 1130 (80-9900) kU/l, respectively (median values with range). TSH in the Se group was 2·1 (0·5-4·3) at baseline, 1·7 (0·0-5·3) mU/l at 6 months, in the placebo group 2·4 (0·7-4·4) and 2·5 (0·2-4·3) mU/l, respectively. QoL was not different between the groups.

CONCLUSION

Six months selenite supplementation increased markers of selenium status but had no effect on serum TPO-Ab, TSH or quality-of-life in euthyroid TPO-Ab-positive women.

Both thyroid autoimmunity and increased serum TSH are independent risk factors for malignancy in patients with thyroid nodules

AIM

To assess the relevance of thyroid autoimmunity and TSH as risk factors for malignancy in thyroid nodules (TN).

SUBJECTS AND METHODS

Retrospective analysis on 2053 patients with single/prevalent TN submitted to fine needle aspiration cytology (FNAC). Anti-thyroid autoantibodies (ATA) [anti-thyroperoxidase (TPOAb), anti-thyroglobulin (TgAb)] and TSH were measured. Cytology was classified as benign (class II), indeterminate (class III), and suspicious or malignant (class IV). Histology was available in 301 patients. Associations of malignancy with independent variables were determined by multivariate logistic regression analysis.

RESULTS

Higher prevalence of class IV (14.2% vs 6.8%: p<0.001) and class III (23.5% vs 17.1%: p<0.001) were found in ATA+ vs ATA- TN. Histology confirmed increased prevalence of cancer in ATA+ (p<0.05) TN and in those with diffuse lymphocytic thyroid infiltration (p<0.05). Interestingly, the prevalence of malignancies observed in operated class III nodules was strikingly lower in ATA+ (1/20, 5%), than in ATA- patients (34/67, 50.7%; p<0.001). Increased independent odds ratio (OR) for malignancy was conferred by any ATA [OR 2.21; 95% confidence interval (CI)=1.49-3.29, p<0.0001]; TPOAb (OR 2.15; CI=1.42-3.25, p<0.0001) and TgAb (OR 1.67; CI=1.05-2.67, p<0.05), by serum TSH>1.0 μUI/ml (OR 1.95; CI=1.01-3.76, p<0.05), and by young age (10-29 yr: OR 2.09; CI=1.02-4.26, p<0.05). A formula was calculated to assess the relative contribution of ATA, TSH, and age to the risk of TN malignancy.

CONCLUSIONS

Both thyroid autoimmunity and increased TSH represent independent risk factors for TN malignancy.

Revisiting immune-based therapies for aggressive follicular cell-derived thyroid cancers

BACKGROUND

With our growing understanding of the immune system and mechanisms employed by tumors to evade destruction, the field of cancer immunotherapy has been revitalized. Concurrent inflammation has long been associated with follicular cell-derived thyroid cancer (FDTC). In the last decade, much research has focused on characterizing the tumor-associated immune response in patients with FDTC.

SUMMARY

Mast cells, natural killer cells, macrophages, dendritic cells, B cells, and T cells have been identified within FDTC-associated immune infiltrate. Collectively, these findings suggest that the immune response to FDTC is compromised and may even promote tumor progression. A more thorough characterization of the tumor-associated immune response in FDTC may lead to the development of immune-based adjuvant therapies for patients with aggressive disease.

CONCLUSIONS

Immune-based therapies could provide essential alternatives to patients that cannot be treated surgically, those with recurrent or persistent lymph node metastases, and those with anaplastic thyroid cancer.

Serum 8-OHdG and HIF-1α levels: do they affect the development of malignancy in patients with hypoactive thyroid nodules?

Aim of the study

This study aimed to evaluate 8-OHdG and hypoxia-inducible factor 1 (HIF-1α) levels in patients with hypoactive thyroid nodules (toxic multi-nodular goiter, Graves’ disease, and Hashimoto's thyroiditis), as these parameters may be related to oxidative stress and the pathogenesis of cancer.

Material and methods

The study included patients diagnosed with Graves’ disease (n = 20), toxic multinodular goiter (n = 20), and Hashimoto thyroiditis (n = 20), and 20 healthy controls. HIF-1α levels were measured in blood samples and 8-OHdG levels were measured in urine – both via ELISA.

Results

HIF-1α and 8-OHdG levels were significantly higher in the patient groups than in the control group (p < 0.05). In the Hashimoto's thyroiditis patients a correlation was observed between 8-OHdG and thyroglobulin antibodies (p = 0.03). A significant relation was found between 8-OHdG and HIF-1α in the patient group (p < 0.01). Carcinoma was detected in 7 of 43 female patients, but not in any of the male patients. No difference was observed in 8-OHdG or HIF-1α levels between the patients with and without papillary carcinoma (p > 0.05). There was no significant difference in 8-OHdG or HIF-1α levels between the patients with biopsy results that were benign, malignant, and non-diagnostic (p > 0.05).

Conclusions

Serum HIF-1α and urine 8-OHdG levels were significantly higher in the patients with thyroid diseases; however, a relationship with cancer was not observed.

The association between papillary thyroid carcinoma and histologically proven Hashimoto's thyroiditis: a meta-analysis

OBJECTIVE

No consensus exists on the association between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT). To resolve this controversy, this study aimed to evaluate the relationship between the two conditions using a meta-analysis.

METHODS

We searched relevant published studies using citation databases including PubMed, Embase, and ISI Web of Science. The effect sizes of clinicopathologic parameters were calculated by odds ratio (OR), weighted mean difference, or hazard ratio (HR). The effect sizes were combined using a random-effects model.

RESULTS

Thirty-eight eligible studies including 10 648 PTC cases were selected. Histologically proven HT was identified in 2471 (23.2%) PTCs. HT was more frequently observed in PTCs than in benign thyroid diseases and other carcinomas (OR=2.8 and 2.4; P<0.001). PTCs with coexisting HT were significantly related to female patients (OR=2.7; P<0.001), multifocal involvement (OR=1.5; P=0.010), no extrathyroidal extension (OR=1.3; P=0.002), and no lymph node metastasis (OR=1.3; P=0.041). Moreover, PTCs with HT were significantly associated with long recurrence-free survival (HR=0.6; P=0.001).

CONCLUSIONS

Our meta-analysis showed that PTC is significantly associated with pathologically confirmed HT. PTC patients with HT have favorable clinicopathologic characteristics compared with PTCs without HT. However, patients with HT need to be carefully monitored for the development of PTC.

Thyroglobulin autoantibodies in patients with papillary thyroid carcinoma: comparison of different assays and evaluation of causes of discrepancies

CONTEXT

Thyroglobulin autoantibodies (TgAb) have been proposed as a surrogate marker of thyroglobulin in the follow-up of differentiated thyroid carcinoma. Commercially available TgAb assays are often discordant. We investigated the causes of discrepancy.

DESIGN

TgAb were measured by three noncompetitive immunometric assays and three competitive RIA in 72 patients with papillary thyroid carcinoma and associated lymphocytic thyroiditis (PTC-T), 105 with papillary thyroid carcinoma and no lymphocytic thyroiditis (PTC), 160 with Hashimoto's thyroiditis, and in 150 normal subjects. The results of the six assays were correlated. TgAb epitope pattern, evaluated by inhibition of serum TgAb binding to thyroglobulin by TgAb-Fab regions A, B, C, and D, were compared in sera which were positive in all six assays (concordant sera) and positive in only one to five assays (discordant sera) were compared. TgAb International Reference Preparation (IRP) was measured in 2007 and 2009.

RESULTS

The correlations of the six assays ranged from -0.01 to 0.93 and were higher in PTC-T and Hashimoto's thyroiditis than in PTC and normal subjects. Two uncorrelated components, one including the three immunometric assays, the other the three RIA, explained 40 and 37% of the total variance of the results of the six assays. The levels of inhibition were higher in concordant sera than in discordant sera by TgAb-Fab region B (27.0%, 21.2-34.0 vs. 6.0%, and 2.7-12.7%) and region C (30.5%, 21.3-37.7 vs. 4.0%, and 1.0-6.5%); thus, the epitope pattern was more homogeneous in concordant sera than in discordant sera. TgAb IRP ranged from 157 to 1088 (expected 1000) IU/ml in 2009; results in 2007 were similar in all but two assays.

CONCLUSIONS

TgAb assays are highly discordant. Discrepancy is lower when comparing assays with similar methodology. Results of TgAb from PTC-T are more concordant than those from PTC because their epitope pattern is more restricted. The internal standardization of TgAb is generally, but not completely, satisfactory.

Serum TSH and risk of papillary thyroid cancer in nodular thyroid disease

CONTEXT

TSH is the main factor involved in the control of proliferation of thyrocytes. Recently, a strong relationship between serum TSH and risk of thyroid malignancy has been reported.

OBJECTIVES

The aim was to review published papers about the relationship between serum TSH and frequency of differentiated thyroid cancer.

EVIDENCE ACQUISITION

PubMed was used to identify studies focused on the relationship between TSH and differentiated thyroid cancer.

EVIDENCE SYNTHESIS

In patients with nodular thyroid disease, the risk of thyroid malignancy increases with serum TSH, and even within normal ranges, higher TSH values are associated with a higher frequency and more advanced stage of thyroid cancer. The likelihood of papillary thyroid carcinoma is reduced when TSH is lower, as in thyroid autonomy, and increased when TSH is higher, as in thyroid autoimmunity. Treatment with l-thyroxine (LT4), which reduces serum TSH, is associated with significantly lower risk of developing clinically detectable thyroid cancer.

CONCLUSIONS

TSH plays a key role in the development of clinically detectable thyroid cancer, and LT4 treatment reduces the risk of thyroid malignancy in patients with nodular thyroid disease. According to the guidelines of the main scientific societies, LT4 therapy is not currently recommended for the treatment of patients with nodular goiter. Even if the available data are not sufficient to advise LT4 treatment in all patients with nodular goiter with the aim of reducing the risk of papillary thyroid carcinoma, we propose that this indication should be reconsidered, taking into account recent evidence reported in the literature.

Hashimoto's thyroiditis is associated with papillary thyroid carcinoma: role of TSH and of treatment with L-thyroxine

The possible association between Hashimoto's thyroiditis (HT) and papillary thyroid carcinoma (PTC) is a still debated issue. We analyzed the frequency of PTC, TSH levels and thyroid autoantibodies (TAb) in 13 738 patients (9824 untreated and 3914 under l-thyroxine, l-T(4)). Patients with nodular-HT (n=1593) had high titer of TAb and/or hypothyroidism. Patients with nodular goiter (NG) were subdivided in TAb-NG (n=8812) with undetectable TAb and TAb+NG (n=3395) with positive TAb. Among untreated patients, those with nodular-HT showed higher frequency of PTC (9.4%) compared with both TAb-NG (6.4%; P=0.002) and TAb+NG (6.5%; P=0.009) and presented also higher serum TSH (median 1.30 vs 0.71 μU/ml, P<0.001 and 0.70 μU/ml, P<0.001 respectively). Independently of clinical diagnosis, patients with high titer of TAb showed a higher frequency of PTC (9.3%) compared to patients with low titer (6.8%, P<0.001) or negative TAb (6.3%, P<0.001) and presented also higher serum TSH (median 1.16 vs 0.75 μU/ml, P<0.001 and 0.72 μU/ml, P<0.001 respectively). PTC frequency was strongly related with serum TSH (odds ratio (OR)=1.111), slightly related with anti-thyroglobulin antibodies (OR=1.001), and unrelated with anti-thyroperoxidase antibodies. In the l-T(4)-treated group, when only patients with serum TSH levels below the median value (0.90 μU/ml) were considered, no significant difference in PTC frequency was found between nodular-HT, TAb-NG and TAb+NG. In conclusion, the frequency of PTC is significantly higher in nodular-HT than in NG and is associated with increased levels of serum TSH. Treatment with l-T(4) reduces TSH levels and decreases the occurrence of clinically detectable PTC.

Clinical and pathological implications of concurrent autoimmune thyroid disorders and papillary thyroid cancer

Cooccurrences of chronic lymphocytic thyroiditis (CLT) and thyroid cancer (DTC) have been repeatedly reported. Both CLT and DTC, mainly papillary thyroid carcinoma (PTC), share some epidemiological and molecular features. In fact, thyroid lymphocytic inflammatory reaction has been observed in association with PTC at variable frequency, although the precise relationship between the two diseases is still debated. It also remains a matter of debate whether the association with a CLT or even an autoimmune disorder could influence the prognosis of PTC. A better understanding about clinical implications of autoimmunity in concurrent thyroid cancer could raise new insights of thyroid cancer immunotherapy. In addition, elucidating the molecular mechanisms involved in autoimmune disease and concurrent cancer allowed us to identify new therapeutic strategies against thyroid cancer. The objective of this article was to review recent literature on the association of these disorders and its potential significance.

Complex thyroid nodules with nondiagnostic fine needle aspiration cytology: histopathologic outcomes and comparison of the cytologic variants (cystic vs. acellular)

Management of complex thyroid nodules (CTN) is a common dilemma due to their high prevalence and frequent nondiagnostic fine needle aspiration cytology (FNAC). In order to know the rate of malignancy, we reviewed our experience about histopathologic diagnosis of CTN with nondiagnostic FNAC, and we analyzed if cytological variants of nondiagnostic FNAC indicated different histopathologic outcomes. We conducted a review of 927 consecutive aspirations performed between 2003 and 2008. We selected patients without history of radiation, with echographic CTN, and nondiagnostic FNAC, who underwent surgery. We analyzed histopathologic results and compared patients with benign and malignant nodules, and searched for differences between patients with cystic changes in FNAC (C-FNAC), and patients with acellular or only bloody FNAC (A-FNAC). Thirty-six patients were included (mean age 45.7 ± 13 years; 30 females). Four patients had malignant nodules; all were papillary carcinomas. Patients with benign nodules had a similar profile to patients with malignant nodules. Patients with C-FNAC (n = 21) were younger (41.3 ± 12.6 vs. 51.8 ± 11.2 years; P < 0.02), had more lymphocytic thyroiditis (33.3 vs. 0%; P < 0.02), a slightly higher rate of carcinoma in the nodule (14.3 vs. 6.6%; P: ns), and also of papillary microcarcinoma outside the nodule (9.6 vs. 0%; P: ns) than patients with A-FNAC. In conclusion, we report an 11.1% malignancy rate in CTN with nondiagnostic FNAC. Nodules with C-FNAC variant had a slightly higher rate of malignancy than A-FNAC, which may be in relation with younger age and higher prevalence of lymphocytic thyroiditis in this group of patients.

Hashimoto's thyroiditis is not associated with increased risk of thyroid cancer in patients with thyroid nodules: a single-center prospective study

BACKGROUND

The risk of thyroid carcinoma in patients with thyroid nodules associated with Hashimoto's thyroiditis (HT) is a debatable issue. The studies defining the true risk of thyroid malignancy are scanty and mainly depend on retrospective series. To eliminate inherent bias of retrospective studies, this prospective study was carried out to evaluate the true malignancy rate of unselected thyroid nodules in patients with HT who underwent fine-needle aspiration cytology (FNAC).

METHODS

These prospective data were gathered on all patients newly diagnosed with thyroid nodules who were sent for FNAC between May 2006 and August 2009. All patients were evaluated for the presence of HT diagnosis by measuring thyroid autoantibodies. If a patient had at least one positive thyroid autoantibody, then the patient was defined as HT with thyroid nodules. There were 164 patients (147 women and 17 men) with thyroid nodules associated with HT (HT group). There were 551 patients (432 women and 119 men) with thyroid nodules without HT (control group). All patients underwent FNAC and ultrasonography (US).

RESULTS

The malignancy rate was 1.0% in HT group (2 out of 191 nodules) and 2.7% in the control group (19 out of 713 nodules), a not significant (p = 0.19) difference. In the two cytologically malignant nodules in HT group and 19 in the control group, papillary thyroid carcinoma was diagnosed after thyroidectomy and histopathological examination. US features of nodule echogenicity, structure, margin, and Doppler flow were similar between the two groups. US features of microcalcification and absence of peripheral halo were more prominent in the nodules of the control group (p = 0.002 and p < 0.001, respectively).

CONCLUSIONS

On the basis of cytopathological criteria, thyroid nodules in patients with HT are no more likely to be malignant than in those without HT. Many of the US features of benign thyroid nodules are similar in patients with and patients without HT.

Male sex, single nodularity, and young age are associated with the risk of finding a papillary thyroid cancer on fine-needle aspiration cytology in a large series of patients with nodular thyroid disease

OBJECTIVE

To evaluate the risk of papillary thyroid carcinoma (PTC) at fine-needle aspiration (FNA) cytology in 34 120 patients.

RESULTS

False positive and false negative rates of FNA cytology were 1.2 and 1.8% in comparison with the histology in 3406 nodules from 3004 patients who underwent surgery. PTC (901 cases) was more frequent in solitary nodule (SN; 446/13 549, 3.3%) than in multinodular goiter (MNG; 411/19 923, 2%, chi(2)=48.8; P<0.0001), and in males (209/6382, 3.3%) than in females (648/26 945, 2.40%, chi(2)=15.58; P<0.0001). PTC prevalence in Graves' disease (GD; 13/286, 4.5%) and Hashimoto's thyroiditis (HT; 31/508, 6.1%) was higher than in SN, this difference being significant in HT (chi(2)=8.7; P=0.003), but not in GD (chi(2)=1.6; P=0.2). Using the multiple logistic regression analysis, independent risk predictors of PTC were determined, which were younger age (odds ratio (OR)=0.97, confidence interval (CI) 0.964-0.974; P<0.0001), male gender (OR=1.44, CI 1.231-1.683; P<0.0001), and SN versus MNG (OR=0.63, CI 0.547-0.717; P<0.0001). The individual risk predictivity was highly improved by including serum TSH in the prediction model, which was measured at FNA in 11 919 patients.

CONCLUSION

A cytology suspicious or indicative of PTC was associated with younger age, male gender, and solitary versus multiple nodularity. These clinical parameters, together with serum TSH, may allow formulation of an algorithm that could be usefully applied to predict the risk of PTC in individual patients when cytology does not give a diagnostic result.

Measuring thyroglobulin autoantibodies by sensitive assay is important for assessing the presence of thyroid autoimmunity in areas with high iodine intake

There is some debate over the clinical utility of measuring serum TgAb to assess the presence of thyroid autoimmunity. To clarify the relationship between TgAb levels and thyroid autoimmunity, a histological examination of thyroid tissue was carried out on unselected living individuals with detectable serum TgAb. 146 patients with a pathological diagnosis of follicular adenoma were selected as subjects. Focal lymphocytic infiltration (FLI) was defined as lymphocytic aggregates of more than 200 in number. A thyroid gland in which 0-1 FLI was observed in a few visual fields of low magnification (20 x 4) in thyroid tissue adjacent to a tumor was judged to be normal and a thyroid gland in which 2 or more FLI were observed was diagnosed as focal lymphocytic thyroiditis (FLT). Serum levels of TgAb and TPOAb were measured by radioimmunoassay. Out of the 146 patients, 18 had detectable serum TgAb and 16 had detectable serum TPOAb. All but one (i.e. 94%) of the 18 TgAb positive patients had FLT and 14 out of the 16 TPOAb positive patients had FLT. The sensitivity (17/32; 53.1%) and specificity (113/114; 99.1%) of TgAb for detecting FLT were higher than those (14/32; 43.7% and 112/114; 98.2%) of TPOAb, but the differences were not significant. In 9 patients who were TgAb positive (but TPOAb negative), 8 (88.9%) had FLT. These results throw doubt on the Laboratory medicine practice guidelines published in Thyroid 2003, in which measuring TgAb is not usually necessary for detecting autoimmune thyroid disease. At least measuring TgAb by sensitive assay is useful for assessing the presence of thyroid autoimmunity in Japan, an area with high iodine intakes.