Associations between Hashimoto Thyroiditis and Clinical Outcomes of Papillary Thyroid Cancer: A Meta-Analysis of Observational Studies

Oncological impact of hypothyroidism and levothyroxine supplementation following hemithyroidectomy in patients with papillary thyroid carcinoma

BACKGROUND

We aimed to evaluate the oncological impact of hypothyroidism and levothyroxine (LT) supplementation after hemithyroidectomy in patients with papillary thyroid carcinoma (PTC).

METHODS

We retrospectively examined 401 patients who underwent hemithyroidectomy for classic PTC and who were postoperatively followed-up with ≥3 thyroid function measurements for ≥24 months.

RESULTS

During 77.4 months of follow-up, 268/401 patients (66.8%) developed hypothyroidism and 19/401 patients (4.7%) showed recurrence. Recurrence rates did not differ between the euthyroidism and hypothyroidism development groups. Recurrence rates were significantly lower in the LT group than in the no-LT group, although mean postoperative thyroid-stimulating hormone (TSH) levels were not different between the two groups. Univariate and multivariate analysis showed that tumors sized >1 cm and lack of LT supplementation were significantly associated with recurrence.

CONCLUSIONS

Postoperative hypothyroidism development was not a risk factor for PTC recurrence after hemithyroidectomy. Nevertheless, LT supplementation reduced recurrence risk without suppressing TSH.

Hashimoto's thyroiditis attenuates progression of papillary thyroid carcinoma: deciphering immunological links

Although some studies have investigated the clinicopathologic relationships between papillary thyroid carcinoma (PTC) and Hashimoto's thyroiditis (HT), there is still no clear understanding of differences in tumor immune microenvironment for PTC with coexisting HT and HT effect on PTC progression. The aim of this study was to clarify immune-mediated mechanisms of coexisting HT, which might influence PTC progression. 30 patients with histologically confirmed conventional-type PTC and 30 patients with PTC and coexisting HT were enrolled in the study. To analyze the role of immune-mediated links between PTC and HT, immunohistochemical investigation was conducted to count the number of different immune cells including T-cytotoxic cells (CD8), plasma cells (CD138), Treg cells (FOXP3), mast cells (MCT), and M2 macrophages (CD163). It was shown that despite the high number of immune cells in the intact thyroid tissues of PTC patients with coexisting HT there were no significant differences in M2 macrophages, mast cells and Treg counts inside PTC with or without HT. PTC with HT was associated with a higher number of CD8+ cells (P < 0.001) reflecting the ability of immune system to generate and recruit T-cytotoxic cells in tumor area, which can explain the protective effect of HT on PTC progression. Lymph node metastases development was associated with an increased number of mast cells, M2 macrophages and Treg along with a decreased plasma cells count regardless of coexisting HT. However, we did not find significant differences in T-cytotoxic cells quantity in node-positive and node-negative patients with or without HT, which encourages further investigation of immune escape mechanisms in PTC.

Correlation Between Hashimoto's Thyroiditis-Related Thyroid Hormone Levels and 25-Hydroxyvitamin D

Objective: The purpose of this study was to further clarify the association of Hashimoto's thyroiditis (HT) and vitamin D deficiency, and to seek the connection between them and related influencing factors. Methods: Data were obtained from subjects who underwent health examinations from January 2018 to December 2018. The diagnosis of HT was based on: antithyroid peroxidase antibody (TPO-Ab) levels >35 IU/ml and/or antithyroglobulin antibody (Tg-Ab) levels >40 IU/ml. Based on the Endocrine Society guidelines, 25-hydroxyvitamin D [25(OH)D] levels ≥30.0 ng/ml were classified as a vitamin D sufficiency; those between 20 and 29.9 ng/ml, as an insufficiency; and those <20 ng/ml, as a deficiency. All statistical analysis was performed by software R. Results: Of a total of 75,436 individuals who were physically examined, 5,656 of them had 25(OH)D levels tested at the same time; 5,230 were enrolled. The level of 25(OH)D in the non-HT group was higher than that in the HT group. Multiple regression analysis showed that HT was statistically significantly correlated with being male, body mass index (BMI), waist circumference, and thyroid-stimulating hormone (TSH). TSH levels in the insufficiency group and deficiency group were higher than those in the sufficiency group. Free triiodothyronine (FT3) and thyroxine (FT4) levels in the insufficiency group and deficiency group were lower than those in the sufficiency group. 25(OH)D increased by 1 ng/ml at the normal reference level, with an increase of 2.78 ng/dl in FT4 concentration and a decrease of 0.17 mIU/L in TSH. Conclusions: Patients with HT present with a reduced 25(OH)D level, and TSH is an independent risk factor for HT. TSH is negatively correlated with 25(OH)D level. FT3 and FT4 levels were positively correlated with 25(OH)D levels.

Suspicious ultrasound characteristics correlate with multiple factors that predict central lymph node metastasis of papillary thyroid carcinoma: Significant role of HBME-1

PURPOSE

Papillary thyroid carcinoma (PTC) is frequently associated with central lymph node metastasis (CLNM). In the present study, we aimed to identify possible risk factors for CLNM in PTC, including suspicious ultrasound (US) features coexisting with thyroid diseases, immunohistochemical markers, and BRAF_V600E. These were used to establish a model to predict the risk of CLNM.

METHODS

From January 2016 to March 2018, we identified a cohort of patients with classic PTC who underwent cervical US and were diagnosed by postoperative pathology. Fine-needle aspiration biopsies were analyzed for the presence ofBRAF_V600E, and immunohistochemistry was used to detect tumor markers. US imaging was performed in accordance with a standardized protocol. A model to determine the risk of CLNM was established using the outcomes of univariate and multivariate analyses.

RESULTS

Age of ≥45 years, male sex, mean tumor diameter of ≥1.0 cm, taller-than-wide tumor shape, multiple PTCs, capsule contact, and HBME-1 expression were significant independent risk predictors of CLNM. Hashimoto's thyroiditis, nodular goiter, andBRAF_V600E were not significantly associated with CLNM. The cutoff value (area under the curve = 0.760) for predicting risk was determined from receiver operating characteristic curves (sensitivity, 75.6 %; specificity, 60.7 %).

CONCLUSIONS

Male sex, age of ≥45 years, mean tumor diameter of ≥1.0 cm, taller-than-wide shape, multiple tumors, capsule contact, and HBME-1 expression were independent predictors of the risk of CLNM in patients with PTC. The risk model may be useful for evaluating patients' prognoses and selecting optimal surgical strategies.

Hashimotos' thyroiditis: Epidemiology, pathogenesis, clinic and therapy

Hashimoto's thyroiditis (HT), the most frequent autoimmune thyroid disorders (AITDs), is the leading cause of hypothyroidism in the iodine-sufficient areas of the world. About 20-30% of patients suffers from HT, whose cause is thought to be a combination of genetic susceptibility and environmental factors that causes the loss of immunological tolerance, with a consequent autoimmune attack to the thyroid tissue and appearance of the disease. The pathologic features of lymphocytic infiltration, especially of T cells, and follicular destruction are the histological hallmark of autoimmune thyroiditis (AIT), that lead to gradual atrophy and fibrosis. An important role in the immune-pathogenesis of AITDs is due to chemokines and cytokines. In about 20% of patients, AITDs are associated with other organ specific/systemic autoimmune disorders. Many studies have demonstrated the relationship between papillary thyroid cancer and AITD. The treatment of hypothyroidism, as result of AIT, consists in daily assumption of synthetic levothyroxine.

Unexpected high-risk pathologic features following thyroidectomy in the chinese immigrant population

OBJECTIVE

To compare rates of unexpected high-risk pathologic features between Chinese and non-Asian patients who underwent thyroidectomy for papillary thyroid cancer.

METHODS

This was a retrospective cohort study at a tertiary academic urban medical center. Patients who underwent thyroidectomy for papillary carcinoma from 2015 to 2017 were included. Patient demographics, tumor characteristics, and tumor histopathology were analyzed. Primary outcome was the presence of adverse histopathologic features such as lymphovascular invasion (LVI) or microscopic/minimal extrathyroidal extension (mETE). Differences between the groups were analyzed using multivariate logistical regression analysis and propensity score-weighted analysis.

RESULTS

One hundred seventy-nine patients were included: 58 Chinese-born and 121 non-Asian. The median age of the cohort was 47 years old (36-58). Twenty-nine percent of patients were male, and 71% were female. There was no statistically significant difference between the two cohorts in rates of LVI, multifocality, extent of surgery, or presence of thyroiditis. Patients with mETE were more likely to have larger tumors (P = 0.00247). Both the multivariate and propensity-weighted models demonstrated that Chinese ancestry was independently associated with an increased rate of unexpected mETE (adjusted prevalence ratio, 2.52; 95% confidence interval, 1.82-3.48).

CONCLUSION

mETE is significantly higher in the immigrant Chinese compared to the non-Asian population. Given the high prevalence of unexpected mETE in the Chinese population, the added risk of this finding should be brought into the discussion during initial surgical planning.

LEVEL OF EVIDENCE

3 Laryngoscope, 130:1844-1849, 2020.

Predictive Factors of Recurrence for Multifocal Papillary Thyroid Microcarcinoma With Brafv600e Mutation: A Single Center Study of 1,207 Chinese Patients

Background: The American Thyroid Association (ATA) guidelines risk stratify Braf^v600e mutated multifocal papillary thyroid microcarcinoma (BMPTMC) into different recurrence risk groups by the extent of extrathyroidal extension (ETE). These findings and modifications for BMPTMC need to be verified in additional studies. Methods: A retrospective cohort study was conducted in BMPTMC patients who underwent total thyroidectomy (TT) and central lymph node dissection (CLND) from 2008 to 2013. Overall, 1,207 patients were included, and predictive factors were identified by univariate and multivariate analysis over a mean 7.5-year follow up. Results: BMPTMC with ETE to capsule shows the same recurrence rate (3.8%) with intrathyroidal BMPTMC. Moreover, BMPTMC with ETE only to strap muscle, which belongs to high-risk group according to ATA guideline, shows relatively lower recurrence rate (13.3%) compared with some intermediate risk categories such as cN1 and >5 pN1. Multivariate analysis using a Cox proportional hazards regression model shows that total tumor diameter (TTD) is associated with significantly higher recurrence for BMPTMC with or without other risk factors (Hazard Ratio (HRO) = 9.86 [95%CI 5.35-18.20], p = 0.00; HRO = 2.32 [95%CI 1.12-4.85], p = 0.02; respectively), while Hashimoto thyroiditis (HT) is found to be protective against the recurrence (HRO = 0.51 [95%CI 0.33-0.79], p = 0.00; HRO = 0.47 [95%CI 0.25-0.89], p = 0.02; respectively). Conclusions: Taken together, capsular ETE and gross ETE to the strap muscles did not have the expected significant influence on recurrence for Chinese BMPTMC patients who underwent TT and CLND. Rather than the extent of ETE, TTD and the lack of HT were identified as predictors for recurrence among BMPTMC with or without other risk factors (vascular invasion, cN1, pN1>5, pN1>3 cm).