Yul Ri Chung

MicroRNA-9 is associated with epithelial-mesenchymal transition, breast cancer stem cell phenotype, and tumor progression in breast cancer

MicroRNAs (miRNAs) are involved in the progression of breast cancer. Some miRNAs, especially the miR-200 family, miR-9, and miR-155 have been reported to be associated with epithelial-mesenchymal transition (EMT) and breast cancer stem cell (BCSC) phenotypes. This study was designed to evaluate the expression levels of these miRNAs in human breast cancer samples and analyzed their relationship with clinicopathologic features of the tumor including breast cancer subtype, EMT, BCSC phenotype, and prognosis. Expression levels of the miR-200 family, miR-9, and miR-155 were quantified using qRT-PCR. Breast cancer subtype, BCSC phenotype (CD44+/CD24− and ALDH1+), and expression of EMT markers (vimentin expression and E-cadherin loss) were evaluated by immunohistochemistry. miR-9 was more highly expressed in HER2+ and triple-negative subtypes than in luminal subtypes. Its expression level was significantly higher in tumors with high T stage, high histologic grade, p53 overexpression, and high proliferation index. Expression of miR-9 was also higher in tumors showing the CD44+/CD24− phenotype, vimentin expression, and E-cadherin loss. Furthermore, high level of miR-9 expression was found to be an independent prognostic factor for poor disease-free survival of the patients. Expression of miR-200a and miR-141 was highest in luminal A subtype, and miR-155 expression was highest in triple-negative subtype. Although the expression levels of some miR-200 family members and miR-155 showed difference with regard to EMT or BCSC phenotype, they were not associated with patients’ prognosis. In conclusion, overexpression of miR-9 is found in tumors with aggressive phenotypes and is associated with poor prognosis in breast cancer, suggesting that it may serve as a potential biomarker for breast cancer progression and a target for treatment.

MicroRNA-222 Expression as a Predictive Marker for Tumor Progression in Hormone Receptor-Positive Breast Cancer

Purpose The microRNA-221/222 (miR-221/222) gene cluster has been reported to be associated with the promotion of epithelial-mesenchymal transition (EMT), downregulation of estrogen receptor-α, and tamoxifen resistance in breast cancer. We studied the expression of miR-222 in human breast cancer samples to analyze its relationship with clinicopathologic features of the tumor, including estrogen receptor status, expression of EMT markers, and clinical outcomes. Methods Quantitative real-time polymerase chain reaction was performed to detect the expression of miR-222 in 197 invasive breast cancers. Expression of EMT markers (vimentin, smooth muscle actin, osteonectin, N-cadherin, and E-cadherin) was evaluated using immunohistochemistry. Results High miR-222 levels were associated with high T stage, high histologic grade, high Ki-67 proliferation index, and HER2 gene amplification. Its expression was significantly higher in the luminal B and human epidermal growth factor receptor 2-positive (HER2+) subtypes than in the luminal A and triple-negative subtypes. In the hormone receptor-positive subgroup, there was a significant negative correlation between miR-222 and estrogen receptor expression, and miR-222 expression was associated with EMT marker expression. In the group as a whole, high miR-222 expression was not associated with clinical outcome. However, subgroup analyses by hormone receptor status revealed that high miR-222 expression was a poor prognostic factor in the hormone receptor-positive subgroup, but not in the hormone receptor-negative subgroup. Conclusion This study showed that miR-222 is associated with down-regulation of the estrogen receptor, EMT, and tumor progression in hormone receptor-positive breast cancer, indicating that miR-222 might be associated with endocrine therapy resistance and poor clinical outcome in hormone receptor-positive breast cancer.

Prognostic value of microRNA-9 and microRNA-155 expression in triple-negative breast cancer

MicroRNAs (miRNAs) are involved in regulation of epithelial-mesenchymal transition (EMT) during breast cancer progression. The purpose of this study was to analyze the clinicopathologic significance of expression of EMT-related miRNAs, miR-9 and miR-155, in triple-negative breast cancers (TNBCs). We analyzed relative expression levels of miR-9 and miR-155 in 190 surgically resected TNBC specimens using quantitative real-time polymerase chain reaction. Then we analyzed the relationship between these miRNA expression levels and EMT marker expression (vimentin, smooth muscle actin [SMA], osteonectin, N-cadherin, E-cadherin, CD146, and ZEB1) assessed by immunohistochemistry. We also evaluated the prognostic significance of these miRNA expression levels. While miR-9 expression level showed a positive correlation with pT category, miR-155 expression level did not correlate with any clinicopathologic features of TNBCs. In relation to EMT phenotype, miR-9 expression was not associated with EMT marker expression except for SMA. However, miR-155 expression level correlated inversely with the expression of several EMT markers including SMA, osteonectin, and CD146. We observed that both miR-9 and miR-155 could be prognostic markers in TNBC in opposite ways; high level of miR-9 expression showed significant association with poor disease-free survival and distant metastasis-free survival (DMFS) in TNBC, while high level of miR-155 expression was associated with better DMFS. Our study suggests that expression levels of both miR-9 and miR-155 can serve as candidates for prognostic biomarkers in TNBCs.

A Pilot Study Evaluating Fine-Needle Aspiration Cytology of Clear-Cell Renal Cell Carcinoma: Comparison of Ancillary Immunocytochemistry and Cytomorphological Characteristics of SurePath™ Liquid-Based Preparations with Conventional Smears.

Objective: Fine-needle aspiration cytology (FNAC) based on a liquid-based preparation is a safe and valuable diagnostic tool. However, due to unfamiliarity with this method and the considerably altered morphology that is associated with it, diagnosing renal cell carcinoma (RCC) from this type of preparation remains a challenge for cytopathologists. The aim of this study was to evaluate the cytomorphological characteristics of SurePath™ (SP)-based preparations compared with conventional smear (CS), and also the role of SP-based FNAC in the diagnosis of clear-cell RCC (CRCC), the most common primary renal malignancy. Study Design: Ex vivo FNAC of both tumors and normal renal parenchyma was prepared from 73 cases. Comparative cytomorphological analysis between liquid-based cytology (LBC) and CS as well as Fuhrman nuclear grading (FNG) was carried out. Immunocytochemistry was performed from normal and CRCC cytology specimens. Results: Normal renal cytology (NRC) showed no significant morphological differences between LBC and CS. For CRCC, LBC showed small, fragmented cell clusters, a 3-dimensional configuration, distinct cytoplasmic vacuoles, and irregular nuclear contours when compared with CS. FNG was overgraded with LBC compared to with CS. AMACR was the most valuable immunocytochemical marker for distinguishing CRCC from NRC. Conclusion: Once cytopathologists become familiar with the altered cytomorphological features of CRCC, FNAC, along with immunocytochemistry, may prove helpful for diagnosis.

Expression of indoleamine 2,3-dioxygenase and infiltration of FOXP3+ regulatory T cells are associated with aggressive features of papillary thyroid microcarcinoma.

BACKGROUND Indoleamine 2,3-dioxygenase (IDO) is overexpressed in many different types of tumor and is associated with activation of FOXP3+ regulatory T cells (Treg cells) and downregulation of cytotoxic cellular immunity in the tumor microenvironment. It has been suggested that IDO inhibitors can be utilized as an effective therapeutic agent against human cancers. However, the expression of IDO and its association with tumor-infiltrating lymphocytes (TILs) remain unclear in papillary thyroid microcarcinoma (PTMC). METHODS Immunohistochemical staining for IDO expression was performed on 124 PTMC samples. TIL subsets (CD3+, CD8+, and FOXP3+ T cells) were counted in serial sections. The relationships between the expression of IDO and infiltration of TIL subsets, as well as the relationships between these immunomodulating factors and clinicopathologic parameters of PTMCs, were analyzed. RESULTS There was a significant correlation between IDO expression and reduced CD3+ TIL and increased FOXP3+ TIL. IDO expression was found in 31% of PTMC and was associated with aggressive clinicopathologic features of the tumor such as extrathyroidal extension (ETE) and multifocality. High infiltration of FOXP3+ Treg cells in the tumor was associated with lymph node metastasis, ETE, and multifocality. Furthermore, high FOXP3/CD8+ ratio was associated with multifocality and lymph node metastasis, and high FOXP3+/CD3+ ratio was related to ETE and multifocality. In multivariate analyses, IDO expression was found to be an independent predictive factor for ETE and tumor multifocality. CONCLUSIONS IDO expression and infiltration of FOXP3+ Treg cells were closely related to each other and were associated with aggressive features of PTMC, suggesting that disruption of antitumor immunity by IDO expression, and thus, infiltration of FOXP3+ Treg cells may contribute to tumor progression in PTMC.

Interobserver Variability of Ki-67 Measurement in Breast Cancer.

Background: As measurement of Ki-67 proliferation index is an important part of breast cancer diagnostics, we conducted a multicenter study to examine the degree of concordance in Ki-67 counting and to find factors that lead to its variability. Methods: Thirty observers from thirty different institutions reviewed Ki-67–stained slides of 20 different breast cancers on whole sections and tissue microarray (TMA) by online system. Ten of the 20 breast cancers had hot spots of Ki-67 expression. Each observer scored Ki-67 in two different ways: direct counting (average vs. hot spot method) and categorical estimation. Intraclass correlation coefficient (ICC) of Ki-67 index was calculated for comparative analysis. Results: For direct counting, ICC of TMA was slightly higher than that of whole sections using average method (0.895 vs 0.858). The ICC of tumors with hot spots was lower than that of tumors without (0.736 vs 0.874). In tumors with hot spots, observers took an additional counting from the hot spot; the ICC of whole sections using hot spot method was still lower than that of TMA (0.737 vs 0.895). In categorical estimation, Ki-67 index showed a wide distribution in some cases. Nevertheless, in tumors with hot spots, the range of distribution in Ki-67 categories was decreased with hot spot method and in TMA platform. Conclusions: Interobserver variability of Ki-67 index for direct counting and categorical estimation was relatively high. Tumors with hot spots showed greater interobserver variability as opposed to those without, and restricting the measurement area yielded lower interobserver variability.

A comparison of Ki-67 counting methods in luminal Breast Cancer: The Average Method vs. the Hot Spot Method

In spite of the usefulness of the Ki-67 labeling index (LI) as a prognostic and predictive marker in breast cancer, its clinical application remains limited due to variability in its measurement and the absence of a standard method of interpretation. This study was designed to compare the two methods of assessing Ki-67 LI: the average method vs. the hot spot method and thus to determine which method is more appropriate in predicting prognosis of luminal/HER2-negative breast cancers. Ki-67 LIs were calculated by direct counting of three representative areas of 493 luminal/HER2-negative breast cancers using the two methods. We calculated the differences in the Ki-67 LIs (ΔKi-67) between the two methods and the ratio of the Ki-67 LIs (H/A ratio) of the two methods. In addition, we compared the performance of the Ki-67 LIs obtained by the two methods as prognostic markers. ΔKi-67 ranged from 0.01% to 33.3% and the H/A ratio ranged from 1.0 to 2.6. Based on the receiver operating characteristic curve method, the predictive powers of the KI-67 LI measured by the two methods were similar (Area under curve: hot spot method, 0.711; average method, 0.700). In multivariate analysis, high Ki-67 LI based on either method was an independent poor prognostic factor, along with high T stage and node metastasis. However, in repeated counts, the hot spot method did not consistently classify tumors into high vs. low Ki-67 LI groups. In conclusion, both the average and hot spot method of evaluating Ki-67 LI have good predictive performances for tumor recurrence in luminal/HER2-negative breast cancers. However, we recommend using the average method for the present because of its greater reproducibility.

Cytologic Diagnosis of Noninvasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features and Its Impact on the Risk of Malignancy in the Bethesda System for Reporting Thyroid Cytopathology: An Institutional Experience

Background This study was performed to analyze cytologic diagnosis of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) and its impact on the risk of malignancy (ROM) in the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). Methods Five thousand five hundred and forty-nine cases of thyroid fine-needle aspiration cytology (FNAC) diagnosed between 2012 and 2014 were included in this study. Diagnostic categories based on TBSRTC were compared with final surgical diagnoses, and the ROM in each category was calculated both when NIFTP was included in malignant lesions and when excluded from malignant lesions. Results Of the 5,549 thyroid FNAC cases, 1,891 cases underwent surgical resection. In final diagnosis, 1,700 cases were revealed as papillary thyroid carcinoma (PTC), and 25 cases were reclassified as NIFTP. The cytologic diagnoses of NIFTP were non-diagnostic in one, benign in five, atypia of undetermined significance (AUS) in 14, follicular neoplasm in two, and suspicious for malignancy in three cases. Collectively, NIFTP/encapsulated follicular variant of PTC (EFVPTC) were more frequently classified as benign, AUS, or follicular neoplasm and less frequently categorized as malignant compared to conventional PTCs. Exclusion of NIFTP from malignant diagnoses resulted in a slight decrease in malignancy rates in non-diagnostic, benign, AUS, follicular neoplasm, and suspicious for malignancy categories without any statistical significance. Conclusions The decrease in the ROM was not significant when NIFTP was excluded from malignant lesions. In thyroid FNACs, NIFTP/EFVPTCs were mostly classified into indeterminate categories. Therefore, it might be feasible to separate NIFTP/EFVPTC from conventional PTC on FNAC to guide clinicians to conservative management for patients with NIFTP/EFVPTC.

Diversity index as a novel prognostic factor in breast cancer

Intratumoral genetic heterogeneity leads to tumor progression and therapeutic resistance. However, due to the difficulty associated with its assessment, the use of this heterogeneity as a prognostic or predictive marker remains limited. To investigate the significance of the Shannon diversity index of gene copy number variation as a tool for measuring genetic heterogeneity in breast cancer, we performed fluorescence in situ hybridization of c-MYC in two sets of invasive breast cancer samples and correlated the Shannon index of c-MYC copy number variation with clinicopathologic features and patient survival. The Shannon index was correlated with average c-MYC copy number and was higher in tumors in which c-MYC was amplified and in those with c-MYC genetic or regional heterogeneity. A high Shannon index was associated with adverse pathologic features including high histologic grade, lymphovascular invasion, p53 overexpression, high Ki-67 proliferation index and negative hormone receptor status. It was also associated with poor disease-free survival in the whole group, in a subgroup excluding c-MYC-amplified cases, and in the hormone receptor-positive subgroup of both a test and a validation set. A high Shannon index for FGFR1 gene copy number variation was also an independent adverse prognostic factor. Our findings suggest that the Shannon diversity index is a measure of intratumoral heterogeneity and can be used as a prognostic factor in breast cancer.

Utility of a Formatted Pathologic Reporting System in Thyroid Core Needle Biopsy: a Validation Study of 1998 Consecutive Cases

Thyroid core needle biopsy (CNB) is increasingly being used as a tool for evaluating thyroid nodules; thus, standardization of its diagnostic terminology is called for. We aimed to analyse the pathologic reporting system of thyroid CNB based on the recently proposed protocol by the Korean Endocrine Pathology Thyroid Core Needle Biopsy Study Group and evaluate its usefulness.