Si-Hyong Jang

High EZH2 Protein Expression Is Associated with Poor Overall Survival in Patients with Luminal A Breast Cancer.

Purpose The enhancer of zeste homologue 2 (EZH2) is a catalytic subunit of the polycomb repressive complex 2, a highly conserved histone methyltransferase. EZH2 overexpression has been implicated in various malignancies, including breast cancer, where is associated with poor outcomes. This study aims to clarify nuclear EZH2 expression levels in breast cancers using immunohistochemistry (IHC) and correlate these findings with clinicopathologic variables, including prognostic significance. Methods IHC was performed on tissue microarrays of 432 invasive ductal carcinoma (IDC) tumors. Associations between EZH2 expression, clinicopathologic characteristics, and molecular subtype were retrospectively analyzed. The relationship between EZH2 protein expression in normal breast tissue and ductal carcinoma in situ (DCIS) was also assessed. Results High EZH2 expression was demonstrated in 215 of 432 tumors (49.8%). EZH2 was more frequently expressed in DCIS and IDC than in normal breast tissue (p=0.001). High EZH2 expression significantly correlated with high histologic grade (p<0.001), large tumor size (p=0.014), advanced pathologic stage (p=0.006), negative estrogen receptor status (p<0.001), positive human epidermal growth factor receptor 2 (HER2) status (p<0.001), high Ki-67 staining index (p<0.001), positive cytokeratin 5/6 status (p=0.003), positive epidermal growth factor receptor status (p<0.001), and positive p53 status (p<0.001). Based on molecular subtypes, high EZH2 expression was significantly associated with HER2-negative luminal B, HER2-positive luminal B, and HER2 type and triple-negative basal cancers (p<0.001). In patients with luminal A, there was a significant trend toward shorter overall survival for those with tumors having high EZH2 expression compared to those with tumors having low EZH2 expression (p=0.045). Conclusion EZH2 is frequently upregulated in breast malignancies, and it may play an important role in cancer development and progression. Furthermore, EZH2 may be a prognostic marker, especially in patients with luminal A cancer.

A Rare Case of Primary Tubular Adenocarcinoma of the Thymus, Enteric Immunophenotype: A Case Study and Review of the Literature

Thymic carcinomas are uncommon malignant tumors, and thymic adenocarcinomas are extremely rare. Here, we describe a case of primary thymic adenocarcinoma in a 59-year-old woman. Histological examination of the tumor revealed tubular morphology with expression of cytokeratin 20 and caudal-type homeobox 2 according to immunohistochemistry, suggesting enteric features. Extensive clinical and radiological studies excluded the possibility of an extrathymic primary tumor. A review of the literature revealed only two global cases of primary tubular adenocarcinomas of the thymus with enteric immunophenotype.

Loss of ARID1A Expression in Gastric Cancer: Correlation with Mismatch Repair Deficiency and Clinicopathologic Features

Purpose The AT-rich interactive domain 1A (ARID1A) gene encodes BRG1-associated factor 250a, a component of the SWItch/Sucrose NonFermentable chromatin remodeling complex, which is considered a tumor suppressor in many tumors. We aimed to investigate the prognostic significance of ARID1A expression in gastric cancers and explore its relationship with clinicopathologic parameters such as mismatch repair protein expression. Materials and Methods Four tissue microarrays were constructed from 191 resected specimens obtained at Soonchunhyang University Cheonan Hospital from 2006 to 2008. Nuclear expression of ARID1A was semiquantitatively assessed and binarized into retained and lost expression. Results Loss of ARID1A expression was observed in 62 cases (32.5%). This was associated with more frequent vascular invasion (P=0.019) and location in the upper third of the stomach (P=0.001), and trended toward more poorly differentiated subtypes (P=0.054). ARID1A loss was significantly associated with the mismatch repair-deficient phenotype (P=0.003). ARID1A loss showed a statistically significant correlation with loss of MLH1 (P=0.001) but not MSH2 expression (P=1.000). Kaplan-Meier survival analysis showed no statistically significant difference in overall survival; however, patients with retained ARID1A expression tended to have better overall survival than those with loss of ARID1A expression (P=0.053). In both mismatch repair-deficient and mismatch repair-proficient groups, survival analysis showed no differences related to ARID1A expression status. Conclusions Our results demonstrated that loss of ARID1A expression is closely associated with the mismatch repair-deficient phenotype, especially in sporadic microsatellite instability-high gastric cancers.

Prognostic and Clinicopathological Significance of Transducer-Like Enhancer of Split 1 Expression in Gastric Cancer

Purpose Transducer-like enhancer of split 1 (TLE1) is a member of the Groucho/TLE family of transcriptional co-repressors that regulate the transcriptional activity of numerous genes. TLE1 is involved in the tumorigenesis of various tumors. We investigated the prognostic significance of TLE1 expression and its association with clinicopathological parameters in gastric cancer (GC) patients. Materials and Methods Immunohistochemical analysis of six tissue microarrays was performed to examine TLE1 expression using 291 surgically resected GC specimens from the Soonchunhyang University Cheonan Hospital between July 2006 and December 2009. Results In the non-neoplastic gastric mucosa, TLE1 expression was negative. In GC, 121 patients (41.6%) were positive for TLE1. The expression of TLE1 was significantly associated with male gender (P=0.021), less frequent lymphatic (P=0.017) or perineural invasion (P=0.029), intestinal type according to the Lauren classification (P=0.024), good histologic grade (P<0.001), early pathologic T-stage (P=0.012), and early American Joint Committee on Cancer stage (P=0.022). In the Kaplan-Meier analysis, the TLE1 expression was significantly associated with longer disease-free (P=0.022) and overall (P=0.001) survival rates. Conclusions We suggested that TLE1 expression is a good prognostic indicator in GCs.

Mediastinal Glomus Tumor: A Case Report and Literature Review

A glomus tumor in the mediastinum is very uncommon, and only five cases have been reported in the English literature. We recently encountered a 21-year-old woman with an asymptomatic mediastinal mass that measured 5.3 × 4.0 cm. Surgical excision was performed, and the tumor was finally diagnosed as mediastinal glomus tumor with an uncertain malignant potential. After reviewing this case and previous reports, we analyzed the clinicopathologic features associated with progression of such a tumor.

Loss of FAT Atypical Cadherin 4 Expression Is Associated with High Pathologic T Stage in Radically Resected Gastric Cancer.

Purpose Recent studies have revealed recurrent alterations in the cell adhesion gene FAT4, a candidate tumor suppressor gene, in cancer. FAT atypical cadherin 4 (FAT4) is a transmembrane receptor involved in the Hippo signaling pathway, which is involved in the control of organ size. Here, we investigated the loss of FAT4 expression and its association with clinicopathological risk factors in gastric cancer. Materials and Methods We assessed the expression of FAT4 by using immunohistochemistry on three tissue microarrays containing samples from 136 gastric cancer cases, radically resected in the Soonchunhyang University Cheonan Hospital between July 2006 and June 2008. Cytoplasmic immunoexpression of FAT4 was semi-quantitatively scored using the H-score system. An H-score of ≥10 was considered positive for FAT4 expression. Results Variable cytoplasmic expressions of FAT4 were observed in gastric cancers, with 33 cases (24.3%) showing loss of expression (H-score <10). Loss of FAT4 expression was associated with an increased rate of perineural invasion (H-score <10 vs. ≥10, 36.4% vs. 16.5%, P=0.015), high pathologic T stage (P=0.015), high tumor-node-metastasis stage (P=0.017), and reduced disease-free survival time (H-score <10 vs. ≥10, mean survival 62.7±7.3 months vs. 79.1±3.1 months, P=0.025). However, no association was found between the loss of FAT4 expression and tumor size, gross type, histologic subtype, Lauren classification, lymphovascular invasion, or overall survival. Conclusions Loss of FAT4 expression appears to be associated with invasiveness in gastric cancer.

Overexpression of YAP1 in EGFR mutant lung adenocarcinoma prior to tyrosine kinase inhibitor therapy is associated with poor survival

EGFR tyrosine kinase inhibitor (EGFR TKI) is approved as first-line treatment for advanced-stage EGFR mutant lung adenocarcinoma (LADC). Yes-associated protein 1 (YAP1), a main effector of the Hippo pathway, is associated with adverse prognosis and disruption of EGFR TKI modulation of non-small cell lung cancer. In this study, we demonstrated a prognostic role of YAP1 in EGFR mutant LADC and efficacy of EGFR TKI therapy. A total of 63 patients, including 41 with paired lung cancer specimens before and after EGFR TKI therapy and 22 with non-paired lung cancer specimens prior to EGFR TKI, were enrolled for examination. Expression of YAP1 protein was evaluated using immunohistochemistry. Fifteen paired cases (36.6%) with high nuclear YAP1 expression were detected in the pre-EGFR TKI LADC group and 21 paired cases (52.5%) after treatment with EGFR TKI. Nuclear YAP1 expression was significantly upregulated after EGFR TKI therapy (P = .002). Fifteen paired cases with high nuclear YAP1 expression before EGFR TKI LADCs showed poorer overall survival (OS) (P = .023) and progression-free survival (PFS) (P = .041). Among the 63 patients under study, those with high nuclear YAP1 expression before EGFR TKI showed shorter OS (P = .038) and PFS (P < .001). High nuclear YAP1 expression in cases with acquired EGFR exon 20 T790 M mutant LADCs showed poorer OS (P < .001). We demonstrated that YAP1 burden before clinical application of EGFR TKI plays a crucial role in prognosis of EGFR mutant LADC treated using EGFR TKI.

Sarcomatoid carcinoma in the trachea: A case report and literature review

Tracheal sarcomatoid carcinoma is an extremely infrequent neoplasm with unclear pathogenesis and clinical outcomes. To date, only two cases have been described in English literature. We report a case of a 37‐year‐old patient complaining of hemoptysis, dyspnea, and cough. An intraluminal polypoid mass in the trachea was found and ultimately diagnosed as tracheal sarcomatoid carcinoma in the cervical trachea with both carcinomatous and sarcomatoid morphology. The patient is alive without recurrence after segmental resection of the trachea. We also present a comparative analysis of our case with a prior tracheal sarcomatoid carcinoma case.

Clinicopathological Significance of Large Tumor Suppressor (LATS) Expression in Gastric Cancer

Purpose The aims of this study were to evaluate the expression of the large tumor suppressor (LATS) genes LATS1 and LATS2 by immunohistochemical staining of gastric cancer, and to evaluate the clinicopathological significance of LATS expression and its correlation with overall survival (OS). Materials and Methods LATS1 and LATS2 expression in a tissue microarray was detected by immunohistochemistry, using 264 gastric cancer specimens surgically resected between July 2006 and December 2009. Results Low expression of LATS1 was significantly associated with more advanced American Joint Committee on Cancer (AJCC) stage (P=0.001) and T stage (P=0.032), lymph node (LN) metastasis (P=0.040), perineural invasion (P=0.042), poor histologic grade (P=0.007), and diffuse-type histology by the Lauren classification (P=0.033). Low expression of LATS2 was significantly correlated with older age (≥65, P=0.027), more advanced AJCC stage (P=0.001) and T stage (P=0.001), LN metastasis (P=0.004), perineural invasion (P=0.004), poor histologic grade (P<0.001), and diffuse-type histology by the Lauren classification (P<0.001). Kaplan-Meier survival analysis revealed significantly poor OS rates in the groups with low LATS1 (P=0.037) and LATS2 (P=0.037) expression. Conclusions Expression of LATS1 or LATS2 is a significant marker for a good prognosis in patients with gastric cancer.

Low angiomotin-p130 with concomitant high Yes-associated protein 1 expression is associated with adverse prognosis of advanced gastric cancer.

Angiomotin (AMOT) promotes angiogenesis and plays a role in neovascularization during tumorigenesis. Recently, the AMOT isoform, AMOT‐p130, was shown to exert a regulatory effect on Yes‐associated protein 1 (YAP1), a major downstream effector of the Hippo pathway. The specific roles of AMOT‐p130 and YAP1 in advanced gastric cancer (AGC) are yet to be established. In this study, a total of 166 patients with AGC were enrolled, and AMOT‐p130 and YAP1 levels were analyzed by immunohistochemistry using tissue microarrays. Low AMOT‐p130 together with high YAP1 expression (n = 30, 18.1%) was associated with high T stage (p = 0.042), high TNM stage (p = 0.025), and venous invasion (p = 0.048). A Kaplan–Meier survival analysis with log‐rank test revealed a significant correlation with decreased AMOT‐p130 coupled with high nuclear YAP1 expression with shorter overall survival (p = 0.0045) and disease‐free survival (p = 0.0028). Furthermore, multivariate analyses showed that the low AMOT‐p130/high YAP1 expression profile was an independent prognostic factor for disease‐free survival (p = 0.008, HR = 1.874, CI, 1.177–2.986) and overall survival (p = 0.012, HR = 1.903, CI, 1.152–3.143). Our findings collectively demonstrate that low AMOT‐p130 combined with high YAP1 expression is correlated with an unfavorable AGC prognosis.