The impact of microscopic extrathyroidal extension on the clinical outcome of classic subtype papillary thyroid microcarcinoma: a multicenter study.

OBJECTIVES: Despite the presumed overdiagnosis of papillary thyroid microcarcinoma (PTMC) which has resulted in a new trend toward less-extensive surgery and a preference for active surveillance, the impact of microscopic extrathyroidal extension (mETE) on the clinical outcomes of PTMC is still controversial. This study assessed the impact of mETE on the clinical outcomes of patients with classic subtype PTMC. METHODS: The data of consecutive patients who underwent thyroidectomy and were histopathologically diagnosed as classic subtype PTMC were analyzed. Cox's proportional hazards model was used to assess the impact of contributing variables on persistent/recurrent disease. Disease-free survival was estimated using the Kaplan-Meier method. RESULTS: This study included 1013 patients (84% females), with a mean follow-up period of 62.5 ± 35.3 months. Patients with mETE had a significantly higher rate of locoregional persistent/recurrent disease than patients without mETE (9.8% vs 2.1%, p < 0.001). The disease-free survival rate was significantly lower in patients with mETE than in those without (90.2% vs 97%, Log-Rank p < 0.001). Furthermore, mETE and neck lymph node involvement were independent predictors of persistent/recurrent disease in multivariate analysis (HR: 2.43, 95% CI:1.02-5.81, p = 0.043; HR: 4.38, 95% CI: 1.7-11.2, p = 0.002, respectively). CONCLUSIONS: In patients with the classic subtype of PTMC, mETE is an independent predictor of persistent/recurrent disease and is associated with a lower DFS rate. However, neck lymph node involvement is the strongest predictor of persistent/recurrent disease. Therefore, PTMCs with mETE and neck lymph node involvement are at a higher risk of persistent/recurrent disease than individuals lacking both characteristics.

Do Histologically Aggressive Subtypes of Papillary Thyroid Microcarcinoma have Worse Clinical Outcome than Non-Aggressive Papillary Thyroid Microcarcinoma Subtypes? A Multicenter Cohort Study.

Histologically aggressive micropapillary thyroid carcinomas (PTMC) subtypes are thought to be associated with an aggressive clinical course. However, evidence for unfavorable clinical outcomes in patients with aggressive PTMC subtypes is not clear. In this study, we intended to determine the difference in clinical outcomes between patients with aggressive and non-aggressive PTMC subtypes. In this multicenter cohort study, the computer-recorded clinical and histopathological data of patients who underwent thyroid surgery between January 2000 - January 2021 in 9 referral centers and were diagnosed as PTMC were analyzed. A total of 1585 patients [female 1340 (84.5%), male 245 (15.5%), mean age 47.9±11.63 years), with a mean follow-up time of 66.55±37.16 months], were included in the study. Ninety-eight cases were diagnosed as aggressive and 1487 as non-aggressive subtypes. Persistent/recurrent disease was observed in 33 (33.7% )and 41 (2.8%) patients with aggressive and non-aggressive subtypes (p<0.001). Diseases-free survival rates were markedly lower in patients with aggressive than in those with non-aggressive PTMC subtypes (66.3 vs. 94.8%, log-rank p<0.001). Moreover, in multivariate analysis, aggressive histology was an independent predictor of persistent/recurrent disease, after controlling for other contributing factors (HR 5.78, 95% CI 3.32-10, p<0.001). Patients with aggressive PTMC subtypes had higher rates of incomplete biochemical and structural response than patients with non-aggressive subtypes as well (p<0.001). Aggressive PTMC subtypes share many characteristics with histologically identical tumors>1 cm in size. Therefore, the histopathological subtype of PTMC should be taken into consideration to tailor a personalized management plan.

Can Age at Diagnosis and Sex Improve the Performance of the American Thyroid Association Risk Stratification System for Prediction of Structural Persistent and Recurrent Disease in Patients With Differentiated Thyroid Carcinoma? A Multicenter Study.

OBJECTIVE: Although the age at diagnosis has been suggested as a major determinant of disease-specific survival in the recent TNM staging system, it is not included in the recent American Thyroid Association (ATA) guidelines to estimate the risk of recurrence. Nevertheless, the effect of sex on differentiated thyroid carcinoma (DTC) recurrence is controversial. Therefore, this multicenter study was conducted to assess whether age at diagnosis and sex can improve the performance of the ATA 3-tiered risk stratification system in patients with DTC with at least 5 years of follow-up. METHODS: In this study, the computer-recorded data of the patients diagnosed with DTC between January 1985 and January 2016 were analyzed. Only patients with proven structural persistent/recurrent disease were selected for comparisons. RESULTS: This study consisted of 1691 patients (female, 1367) with DTC. In Kaplan-Meier analysis, disease-free survival (DFS) was markedly longer in females only in the ATA low-risk category (P = .045). Nevertheless, a markedly longer DFS was observed in patients aged <45 years in the ATA low- and intermediate-risk categories (P = .004 and P = .009, respectively), whereas in patients aged <55 years, DFS was markedly longer only in the ATA low-risk category (P < .001). In the Cox proportional hazards model, ages of ≥45 and ≥55 years at diagnosis and the ATA risk stratification system were all independent predictors of persistent/recurrent disease. CONCLUSION: Applying the age cutoff of 45 years in the ATA intermediate- and low-risk categories may identify patients at a higher risk of persistence/recurrence and may improve the performance of the ATA risk stratification system, whereas sex may improve the performance of only the ATA low-risk category.

The association of TSH-receptor antibody with the clinical and laboratory parameters in patients with newly diagnosed Graves' hyperthyroidism: experience from a tertiary referral center including a large number of patients with TSH-receptor antibody-negative patients with Graves' hyperthyroidism.

INTRODUCTION: Although the TSH-receptor antibody (TRAb) plays a central role in the pathogenesis of Graves' disease (GD), the association between TRAb at first diagnosis and clinical and laboratory parameters is not well known. On the other hand, a minority of patients with GD may be TRAb negative, and there is a lack of adequate evidence to demonstrate the clinical and laboratory characteristics of these patients. Therefore, we aimed to investigate the association of TRAb at the initial diagnosis of GD with the clinical and laboratory parameters in a large number of patients with GD and to compare the clinical and laboratory parameters between patients with high TRAb levels and TRAb-negative patients. MATERIAL AND METHODS: This study included 440 patients [326 (74%) female, 114 (26%) male]. All patients were classified according to gender, age, smoking habit, and TRAb levels. RESULTS: TRAb levels were significantly higher in male compared to female patients and in smokers compared to non-smokers. Smoking male patients had the highest TRAb levels. In regression analysis, goiter size, male gender, cigarette smoking, Graves' orbitopathy, fT3, and anti-TPO antibody levels were independently associated with high TRAb levels, while age at diagnosis and fT4 levels were not independently associated with high TRAb levels. TRAb-negative GD was diagnosed in 80 (18%) patients. TRA-negative patients had markedly less severe clinical and laboratory hyperthyroidism compared to patients with high TRAb levels. Moreover, the smoking habit was significantly lower in patients with TRAb-negative GD. CONCLUSIONS: According to our study results, TRAb levels at the initial diagnosis of GD are differently associated with clinical and laboratory parameters. Male patients and smoking patients with GD tended to have markedly higher TRAb levels and more severe clinical hyperthyroidism. Therefore, besides other contributing factors, male gender and smoking may affect TRAb levels and consequently the severity of hyperthyroidism in patients with GD. Furthermore, male gender and smoking may have a synergistic effect on TRAb levels and consequently on the severity of hyperthyroidism in patients with GD.