Bo Youn Cho

The association of the BRAFV600E mutation with prognostic factors and poor clinical outcome in papillary thyroid cancer

The effects of the BRAFV600E mutation on prognostic factors and poor clinical outcomes in papillary thyroid cancer (PTC) have not been fully quantified. The authors performed comprehensive meta‐analysis to assess the strength of associations between these conditions and the BRAFV600E mutation.

Detection of BRAFV600E mutation on fine needle aspiration specimens of thyroid nodule refines cyto‐pathology diagnosis, especially in BRAFV600E mutation‐prevalent area

Background  Between 10 and 30% of the fine needle aspiration biopsies (FNABs) of thyroid nodules are diagnosed as ‘indeterminate’. A molecular diagnostic method is needed to reduce unnecessary surgery in this group. In Korea, most thyroid cancer is the classic papillary type and the BRAFV600E mutation is highly prevalent.

Clinical significance of elevated level of serum antithyroglobulin antibody in patients with differentiated thyroid cancer after thyroid ablation

objective This study was designed to investigate whether an elevated serum antithyroglobulin antibody (TgAb) reflects cancer recurrence in thyroglobulin (Tg)‐undetectable patients with differentiated thyroid carcinoma (DTC) after thyroid ablation.

Changes in the Clinicopathological Characteristics and Outcomes of Thyroid Cancer in Korea over the Past Four Decades

BACKGROUND Thyroid cancer has increased globally, with a prominent increase in small, papillary thyroid cancers (PTC). The Korean population has a high iodine intake, high prevalence of BRAF V600E mutations, and family histories of thyroid cancer. We examined the clinicopathological characteristics and outcomes of thyroid cancers in Korean patients over four decades. METHODS The medical records of 4500 thyroid cancer patients, between 1962 and 2009 at a single center, including 3147 PTC patients, were reviewed. RESULTS The mean age of the patients was 46.8±13.2 years; women accounted for 82.9% of the patients, and the median follow-up duration was 4.8 years (mean 7.0±5.8 years, range 1-43 years). The number of patients visiting the clinic increased from 411 during 1962-1990 to 2900 during 2000-2009. Age at diagnosis increased from 39.6±12.9 to 48.6±12.4 years. The male to female ratio increased from 1:6 to 1:4.5. The proportion of small (<1 cm) tumors increased from 6.1% to 43.1%, and the proportion of cancers with lymph node (LN) involvement or extrathyroidal extension (ETE) decreased from 76.4% to 44.4% and from 65.5% to 54.8% respectively. Although there were decreases in the proportion of LN involvement and ETE, these decreasing rates were not proportional to the expected rates based on the decreased proportion of large tumors. The overall recurrence and mortality rates were 13.3% and 1.4%. The five-year recurrence rate significantly decreased (from 11% to 5.9%), and the five-year mortality also improved (from 1.5% to 0.2%). CONCLUSIONS The incidence of thyroid cancer has rapidly increased, with a decrease in tumors of large size, LN involvement, and ETE, although the decreasing rates of LN involvement and ETE were not as prominent as decreasing rates of large size tumors. The mortality and recurrence rates have also decreased. Future long-term follow-up of patients diagnosed in the most recent decade is needed to confirm the prognostic characteristics of Korean PTC patients.

Relationship between expression of the sodium/iodide symporter and 131I uptake in recurrent lesions of differentiated thyroid carcinoma

Abstract. The sodium/iodide symporter (NIS) is known to be responsible for the active accumulation of iodide within the thyroid gland. We evaluated the relationship between the expression of NIS in primary or lymph node lesions and iodine-131 uptake in recurrent lesions of differentiated thyroid cancer. In 67 patients with differentiated thyroid cancer (5 follicular and 62 papillary carcinomas), the expression of NIS was analysed by immunohistochemical staining using polyclonal antibodies against human NIS. We used paraffin block tissues of primary tumours or metastatic lesions, and also assessed 131I uptake in recurrent lesions of thyroid cancer on postoperative 131I whole-body scan. Immunohistochemical staining was positive in 22 patients (32.8%), including 2 of 5 follicular and 20 of 62 papillary carcinomas. Recurrence was confirmed in 40 patients pathologically or clinically by serum thyroglobulin, 131I scan, fluorine-18 fluorodeoxyglucose positron emission tomography and/or computed tomography. Among these 40 patients, 28 showed positive uptake on 131I scan. Fourteen tumour specimens out of 28 (50%) were positive by NIS immunohistochemical staining. The remaining 12 patients with recurrent cancer showed negative 131I scans, and all specimens were negative by NIS immunohistochemical staining. Thus, NIS immunohistochemical staining predicted 131I uptake in recurrent cancer with a 100% positive predictive value and a 46.2% negative predictive value. There was no difference in the positivity of NIS according to the site of recurrence on 131I scan. Outcome of 131I therapy could be assessed in 22 of the 28 patients who showed 131I uptake in recurrent lesions. Patients with positive NIS immunostaining responded to 131I therapy better than did patients with negative immunostaining (P<0.05). In conclusion, NIS immunohistochemical staining showed a high positive predictive value in predicting iodine uptake. Positive immunohistochemical staining of human NIS in primary or lymph node lesions may predict 131I accumulation and effectiveness of 131I therapy in recurrent lesions.

Diagnostic Value of Galectin-3, HBME-1, Cytokeratin 19, High Molecular Weight Cytokeratin, Cyclin D1 and p27kip1 in the Differential Diagnosis of Thyroid Nodules

The distinction between benign and malignant thyroid tumors is critical for the management of patients with thyroid nodules. We applied immunohistochemical staining for galectin-3, HBME-1, cytokeratin 19 (CK19), high molecular weight cytokeratin (HMWCK), cyclin D1 and p27kip1 in 295 thyroid lesions to determine their diagnostic accuracy. The expression of all markers was significantly associated with differentiated thyroid carcinoma (DTC).The sensitivity for the diagnosis of DTC was 94.7% with galectin-3, 91.3% with HBME-1, and 90.3% with CK19. The specificities of these markers were 95.5%, 69.7%, and 83.1%, respectively. Combining these markers, co-expression of galectin-3 and CK19 or galectin-3 and HBME-1 was seen in 93.2% of carcinomas but in none of the benign nodules. Comparing follicular variant of papillary carcinoma (FVPC) with follicular carcinoma (FC), the expression of galectin-3, CK19, and HMWCK was significantly higher in FVPC. When comparing FC with FA, the expression of galectin-3 and HBME-1 was significantly higher in FC. These results suggest that 1) galectin-3 is a useful marker in the distinction between benign and malignant thyroid tumors, 2) the combined use of HBME-1 and CK19 can increase the diagnostic accuracy, and 3) the use of CK19 and HMWCK can aid in the differential diagnosis between PC and FC.

Elevated risk of papillary thyroid cancer in Korean patients with Hashimoto's thyroiditis†

Hashimotos thyroiditis (HT) and higher levels of thyroid‐stimulating hormone (TSH) have been proposed as risk factors for papillary thyroid cancer (PTC), but this issue is still being debated. The purpose of this study was whether HT was related to the risk of PTC over TSH.

Subclinical hypothyroidism (SCH) is not associated with metabolic derangement, cognitive impairment, depression or poor quality of life (QoL) in elderly subjects.

The objective of this study was to examine the relationship between SCH and metabolic and neuropsychiatric derangements in Korean elderly subjects. Nine hundred and eighteen euthyroid and SCH subjects aged 65 years and older were enrolled in the present study. We compared anthropometric (age, sex, blood pressure, body mass index=BMI, body fat contents=BF, waist circumference=WC and hip circumference=HC), laboratory (glucose and lipid profile, renal and liver functions, and C-reactive protein=CRP levels), and neuropsychiatric (neuropsychological function, mood, and QoL) parameters of SCH subjects with those of euthyroid subjects. Associated metabolic disorders of the subjects were also compared between the euthyroid and SCH groups. We could not observe any differences between the SCH group and the euthyroid group with regards to metabolic parameters as well as neuropsychiatric parameters. These findings may suggest that SCH does not appear to be associated with metabolic and neuropsychiatric derangement in elderly subjects.

Prognostic factors for Korean patients with anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC), although rare, is one of the most aggressive human cancers, and patients with ATC have extremely poor prognoses despite various therapeutic measures. We wished to determine the prognostic factors of survival and effect of treatment on survival rate in patients with ATC.

S100A4 expression is associated with lymph node metastasis in papillary microcarcinoma of the thyroid

The detection of papillary microcarcinomas of the thyroid is increasing due to frequent use of ultrasound and fine-needle aspiration biopsy. Although most of the papillary microcarcinomas remain quiescent and follow an indolent clinical course, some behave aggressively and metastasize early, giving rise to clinically significant disease. There have been few studies concerning factors predictive of lymph node metastasis in papillary microcarcinomas. We analyzed the expression of S100A4, cyclin D1, p27 and MUC1, the presence of the BRAFV600E mutation and the clinicopathological features of the tumors, including patient age, tumor size (≥5 vs <5 mm), extrathyroidal extension, multifocality, histological subtype, sclerosis and encapsulation, in a series of 198 papillary microcarcinomas in relation to lymph node metastasis to determine the predictive factors of lymph node metastasis. On univariate analysis, tumor size of 5 mm or more, extrathyroidal extension, multifocality, sclerosis and the expression of S100A4 and cyclin D1 predicted lymph node metastasis, whereas patient age, expression of p27 and MUC1 and the BRAFV600E mutation did not. Moreover, tumor size 5 mm or more, multifocality and expression of S100A4, especially its strong expression in the invasive fronts, were significantly associated with macrometastasis and lateral node metastasis. On multivariate analysis, multifocality and expression of S100A4 were found to be common independent predictive factors of lymph node metastasis, macrometastasis and lateral node metastasis. In conclusion, S100A4 expression in papillary microcarcinomas may indicate the presence of nodal metastasis. Thus, S100A4 immunohistochemistry may be valuable for predicting metastatic potential in papillary microcarcinomas.