• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1267-1272
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• 2012

Background and Objective: The optimal resection extent for clinically unilateral papillary thyroid microcarcinoma (PTMC) remains controversial. The objective was to investigate risk factors associated with occult contralateral carcinoma, and put emphasis on the predictive value of preoperative BRAF mutation. Materials and Methods: 100 clinically unilateral PTMC patients all newly diagnosed, previously untreated were analyzed in a prospective cohort study. We assessed the T1799A BRAF mutation status in FNAB specimens obtained from all PTMC patients before undergoing total thyroidectomy (TT) and central lymph node dissection (CLND) for PTMC. Univariate and multivariate analyses were used to reveal the incidence of contralateral occult cancer, difference of risk factors and predictive value, with respect to the following variables: preoperative BRAF mutation status, age, gender, tumor size, multifocality of primary tumor, capsular invasion, presence of Hashimoto thyroiditis and central lymph node metastasis. Results: 20 of 100 patients (20%) had occult contralateral lobe carcinoma. On multi-variate analysis, preoperative BRAF mutation (p = 0.030, OR = 3.439) and multifocality of the primary tumor (p = 0.004, OR = 9.570) were independent predictive factors for occult contralateral PTMC presence. However, there were no significant differences between the presence of occult contralateral carcinomas and age, gender, tumor size, capsular invasion, Hashimoto thyroiditis and central lymph node metastasis. Conclusions: Total thyroidectomy, including the contralateral lobe, should be considered for the treatment of unilateral PTMC if preoperative BRAF mutation is positive and/or if the observed lesion presents as a multifocal tumor in the unilateral lobe.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3361-3363
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• 2015

Background: Despite the majority of papillary thyroid microcarcinoma (PTMC) patients having an excellent prognosis, cervical lymph node metastases are common. The purpose of this study was to investigate the incidence and the predictive risk factors for occult central compartment lymph node metastasis (CLNM) in PTMC patients. Materials and Methods: 178 patients with clinically node-negative (cN0) PTMC undergoing prophylactic central compartment neck dissection in our hospital from January 2008 to Jun 2010 were enrolled. The relationship between CLNM and the clinical and pathological factors such as gender, age, tumor size, tumor number, tumor location, extracapsular spread (ECS), and coexistance of chronic lymphocytic thyroiditis was analyzed. Results: Occult CLNM was observed in 41% (73/178) of PTMC patients. Multivariate analysis showed that male gender, tumor size (${\geq}6mm$) and ECS were independent variables predictive of CLNM in PTMC patients. Conclusions: Male gender, tumor size (${\geq}6mm$) and ECS were risk factors of CLNM. We recommend a prophylactic central lymph node dissection (CLND) should be considered in PTMC patients with such risk factors.

• Korean Journal of Head & Neck Oncology
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• v.27 no.1
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• pp.38-41
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• 2011

Background and Objectives : Although it is well established that patients with papillary thyroid microcarcinoma (PTMC) have a highly favorable prognosis, the extent of thyroid surgery for PTMC remains unclear. According to the 2011 revised Korean Thyroid Association guideline, the choice of surgical strategy(total thyroidectomy versus lobectomy) for PTMC depends on solely preoperative diagnostic scrutinies-ultrasonography and fine needle aspiration cytology. We want to know how accurately these preoperative diagnostic scrutinies define the choice of surgical strategy for PTMC. Materials and Methods : For 119 patients who underwent total thyroidectomy with central neck dissection for PTMC, retrospectively, we compared the choice of surgery according to preoperative work up and postoperative pathologic findings. Results : Overall accuracy of the choice of surgery by preoperative work up was 61%. Among patients recommended lobectomy on preoperative work up, completion thyroidectomy on postoperative pathology might be necessary for 60% of patients and hidden central node metastasis was revealed in 31% of patients. Conclusions : The results of this study compel us to reinvestigate the current treatment guideline for PTMC. On current guideline according to the sonography and fine needle aspiration cytology, it might be thought to be better to choose more aggressive surgical strategy.

• Korean Journal of Head & Neck Oncology
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• v.24 no.1
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• pp.47-52
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• 2008

Purpose：The incidence of papillary thyroid microcarcinoma(PTMC) has increased due to the widespread use of high resolution ultrasonography and fine-needle aspiration biopsy. However, the clinical and biologic behaviors of PTMC is debatable. The aim of this study was to describe clinicopathologic features of PTMC and to suggest whether tumor size(5mm) might prove the useful parameter for determining the surgical strategy in PTMC. Material and Methods：From Jan. 2000 to Dec. 2005, 1355 of 2678 patients with papillary thyroid carcinoma were identified as having PTMC, based on tumor size${\leq}$10mm(50.6%). Among patients with PTMC, we further separated tumors<5mm(minute group：group M) from those 5 to 10mm(tiny group：group T). We compared the clinicopathological characteristics and the TNM stagings between two groups. Results：There were 114(8.4%) men and 1241(91.6%) women with a median age of 47 years(range；13-79). During a mean follow-up of 47.3(range；22-93), 13 patients(1.0%) developed locoregional recurrences and 3 patients(0.2%) showed distant metastases at initial presentation. Statistical analysis revealed that the presence of extracapsular invasion(p<0.0001), invasion to adjacent structure(p<0.0001), multifocality(p<0.0001), central lymph node metastasis(p<0.0001), and lateral lymph node metastasis(p<0.0001) were all significantly higher in tiny group(tumor${\geq}$5mm). Furthermore, minute group demonstrated a significantly lower tumor stage(AJCC TNM classification) compared with tiny group(p<0.0001). Conclusion：Patients with PTMC have a favorable treatment outcomes, although the distinction needs to be made with reference to the clinicopathologic behaviors. It would be reasonable to consider that tumor size(5mm) would be useful parameter for the treatment strategy of PTMC.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.2947-2951
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• 2015

Background: The phenomenon of occult carcinoma maybe observed in patients with clinically unilateral papillary thyroid microcarcinoma (PTMC). Although many studies have reported that the $BRAF^{T1799A}$ mutation is associated with aggressive PTMC, the relationship between $BRAF^{T1799A}$ mutation and occult carcinoma is unclear. The aim of this study was to investigate the risk factors, including $BRAF^{T1799A}$ mutation, for occult contralateral carcinoma in clinically unilateral PTMC accompanied by benign nodules in the contralateral lobe. Materials and Methods: From January 2011 to December 2013, we prospectively enrolled 89 consecutive PTMC patients with clinically unilateral carcinoma accompanied by benign nodules in the contralateral lobe who received a total thyroidectomy and cervical lymph node dissection. $BRAF^{T1799A}$ mutation was tested by pyrosequencing on postoperative paraffin specimens. The frequency and predictive factors for occult contralateral carcinoma were analyzed with respect to the following variables: age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or $BRAF^{T1799A}$ mutation. Results: A total of 36 patients (40.4%) had occult PTMC in the contralateral lobe. The median diameter of the occult tumors was $0.33{\pm}0.21cm$. The $BRAF^{T1799A}$ mutation was found in 38 cases (42.7%). According to the univariate analysis, there were no significant differences between the presence of occult contralateral carcinoma and age, gender, family history, tumor size, presence of Hashimoto thyroiditis, extrathyroidal extension, central lymph node metastasis, multifocality of primary tumor, or $BRAF^{T1799A}$ mutation. Conclusions: Using current methods, it is difficult to preoperatively identify patients with PTMC, and further research is needed to determine predictive factors for the presence of occult contralateral carcinoma in patients with unilateral PTMC.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1605-1608
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• 2015

Purpose: To investigate the expression of Ki67 protein in papillary thyroid microcarcinoma(PTMC), and to analyze its clinical significance. Materials and Methods: Ki67 protein expression was evaluated in the tissues of 108 human PTMC and 50 other benign papillary hyperplasia of thyroid specimens using immunohistochemistry. Results: The expression intensity of Ki67 in PTMC and benign papillary hyperplasia of thyroid specimens were $1.45{\pm}1.83%$ and $0.46{\pm}0.46%$.The positive expression rates were 46.3% and 14%. There were significant differences between these two groups (p<0.01). There was no significant variation of the expression intensity and positive expression rates of Ki67 in PTMC with gender, age, position of the tumor and the level of TSH pre-operation (p>0.05), but these parameters varied with tumor size, invasion by membrane and cervical lymph node metastasis (p<0.05 or p<0.01). Conclusions: The expression of Ki67 in PTMC was related to tumor size, invasion by membrane and cervical lymph node metastasis, and could be the important indicator for judging clinical progress and estimating prognosis.

• Korean Journal of Head & Neck Oncology
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• v.31 no.2
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• pp.6-10
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• 2015

Background and Objective : Papillary thyroid microcarcinoma(PTMC) is known as slow growing cancer with good prognosis. However, extrathyroidal extension may increase the risk of cervical lymph node metastasis and local invasion to surrounding structures. The aim of this study was to assess the characteristic features of the tumor invading the posterior thyroid capsule. Material and Methods : We made a retrospective review of 123 PTMC patients with thyroid capsule invasion, pathologically staged as T3 or T4. 74 patients (60.2%) had invasion to posterior thyroid capsule (group A) while 49 patients (39.8%) had invasion to-anterior thyroid capsule or anterior wall of trachea (group B). We assessed the clinicopathologic factors of the patients according to the location of capsular invasion of PTMC. Results : There was no difference regarding age, gender, T and N classification and incidence of lymph node metastasis between two groups. Local invasion rate to recurrent laryngeal nerve was 6.8% in patients with posterior thyroid capsule invasion, while the incidence was zero in those with capsular invasion to other locations Conclusion : Increased risk of local invasion to the recurrent laryngeal nerve should be considered in patients with PTMC presenting invasion of the posterior capsule.

• Journal of Korean Traditional Oncology
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• v.19 no.1
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• pp.53-59
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• 2014

Objectives : Thyroid cancer is one of the most common and rapid increases of malignancy worldwide. It is the aim of the present a case of papillary thyroid microcarcinoma (PTMC) treated with acupuncture alone to derive further studies of the determination of treatment options for PTMC, such as surgery, acupuncture and observation alone, etc. Method : A 51-year-old woman with malignancy of thyroid nodule ($0.89{\times}0.59cm$) was referred to our hospital on January 2010. We applied to the acupuncture alone three times weekly by the patient's decision from January 2010 to November 2014. Blood tests were conducted three times during the treatment period and ultrasonography was performed every 6 months. Results : Both laboratory data and tumor size results showed no deteriorations as compared with those of initial examination. The patients has been survived in healthy state without any metastasis or disease progression on November, 2014. Conclusion : This case presents a possibility that acupuncture or observation alone can be provided as an option in the treatment means for patients with PTMC. Further study will need to study more longer follow-up and a large number of patients for PTMC using acupuncture or observation alone.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.8613-8616
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• 2014

Background: The diagnostic approach to thyroid nodules involves ultrasound-guided fine needle aspiration biopsy (US-FNAB). We especially aimed to evaluate the contribution and the place of US-FNAB in preoperative evaluation of the malignant cases and draw attention to discordant cases diagnosed with papillary thyroid microcarcinoma (PTMC). Materials and Methods: A total of 276 cases were retrospectively reviewed who were subsequently diagnosed with a malignancy and who underwent US-FNAB. Results: Some 45 were found to have previously undergone the US-FNAB procedure. Of the patients in whom the surgical specimen was diagnosed with a malignancy, 21 (46.7%) were diagnosed as malignant or suspicious for malignancy, and 24 (53.3%) were concluded as benign or insufficient for diagnosis. Patients with the diagnosis of PTMC outnumbering the others was a striking finding (11 cases, 24%). Conclusions: We suggest performing repeat aspiration biopsy considering sampling errors in cases where inconsistency exists between clinical findings and cytological results in thyroid nodules smaller than 10 mm in diameter and with suspicious findings on ultrasonography.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.341-344
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• 2001

Over the last 20 years, biodegradable materials in medical applications have been studied extensively. Among these materials, poly(ε-caprolactone) and poly(trimethylene carbonate)(PTMC) are attractive biopolymers to be used as biodegradable sutures, artificial skin, drug release system. It was known that PCL is a nontoxic biocompatible semicrystalline polymer with melting point of 63℃, and PTMC is an amorphous or little crystaline polymer. (omitted)