Detection of TERT Promoter Mutations Using Targeted Next-Generation Sequencing: Overcoming GC Bias through Trial and Error / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Detection of telomerase reverse transcriptase (TERT) promoter mutations is a crucial process in the integrated diagnosis of glioblastomas. However, the TERT promoter region is difficult to amplify because of its high guanine-cytosine (GC) content (> 80%). This study aimed to analyze the capturing of TERT mutations by targeted next-generation sequencing (NGS) using formalin-fixed paraffin-embedded tissues. @*Materials and Methods@#We compared the detection rate of TERT mutations between targeted NGS and Sanger sequencing in 25 cases of isocitrate dehydrgenase (IDH)-wildtype glioblastomas and 10 cases of non-neoplastic gastric tissues. Our customized panel consisted of 232 essential glioma-associated genes. @*Results@#Sanger sequencing detected TERT mutations in 17 out of 25 glioblastomas, but all TERT mutations were missed by targeted NGS. After the manual visualization of the NGS data using an integrative genomics viewer, 16 cases showed a TERT mutation with a very low read depth (mean, 21.59; median, 25), which revealed false-negative results using auto-filtering. We optimized our customized panel by extending the length of oligonucleotide baits and increasing the number of baits spanning the coverage of the TERT promoter, which did not amplify well due to the high GC content. @*Conclusion@#Our study confirmed that it is crucial to consider the recognition of molecular bias and to carefully interpret NGS data.

Portal Biliopathy Misdiagnosed as Hilar Cholangiocarcinoma / 대한소화기학회지

Portal biliopathy refers to the changes in the bile duct caused by portal vein thrombosis or obstruction. It is assumed to be caused by cavernous transformation due to the development of the venous system surrounding the bile duct, but the exact pathology is still unknown. Biliary morphologic abnormalities of portal biliopathy are discovered incidentally on radiographic images, but it is sometimes difficult to differentiate them from cholangiocarcinoma. Given the poor prognosis of cholangiocarcinoma, a surgical approach can be considered when the diagnosis is uncertain. Herein, we report a case of portal biliopathy with bile ductal wall thickening, which was diagnosed after surgical resection was performed due to the presumed diagnosis of cholangiocarcinoma.

Evaluation of the American Joint Committee on Cancer (AJCC) 8th Edition Staging System for Hepatocellular Carcinoma in 1,008 Patients with Curative Resection / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Recently, the 8th edition staging system of the American Joint Committee on Cancer (AJCC) for hepatocellular carcinoma (HCC) was released, including a change in T category. We aimed to validate the new AJCC system. @*Materials and Methods@#The predictive value of the new AJCC was validated in comparison to the previous edition, in a total 1,008 patients who underwent curative resection for HCC as initial treatment. @*Results@#The 2-year area under the curve values for recurrence-free survival (RFS) and overall survival (OS) were comparable in the 7th and 8th editions. Stage migration was observed in 63 patients (6.3%); from T2 to T1a for 44 patients and from T3 to T4 for 19 patients. The RFS and OS were not different between T1a and T1b in the 8th edition. For solitary tumors ≤ 2 cm, those with microvascular invasion had lower RFS and OS values than those without although they were all classified as T1a in the 8th edition. Tumors involving a major branch of the portal or hepatic vein (T4 by the 8th edition and T3b by the 7th edition) had shorter RFS and OS than multifocal tumors, at least one of which was > 5 cm (T3 by the 8th edition and T3a by the 7th edition). @*Conclusion@#The AJCC 8th edition staging system for HCC showed comparable predictive performance to the 7th edition. It is desirable in a future revision to consider sub-stratification of solitary tumors ≤ 2 cm (T1a) depending on the presence of vascular invasion, which is not included in the 8th edition.

Investigating Trk Protein Expression between Oropharyngeal and Non-oropharyngeal Squamous Cell Carcinoma: Clinical Implications and Possible Roles of Human Papillomavirus Infection / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: The relationship between head and neck squamous cell carcinoma (HNSCC) and subtypes of tropomyosin-related kinase (Trk) has not been studied in-depth. In this study, we evaluated the expression patterns of TrkA, TrkB, and panTrk and their clinicopathological significance as well as association with p16 expression and human papilloma virus (HPV) status. MATERIALS AND METHODS: Total of 396 radically resected oropharyngeal (n=121) and non-oropharyngeal (n=275) HNSCCs were included. Immunohistochemistry for TrkA, TrkB, and panTrk was performed. In addition, p16 immunohistochemistry was performed to assess the HPV status. Using HPV-negative HNSCC cell lines, FaDu and CAL27, HPV type 16 E6/E7 gene was transfected, and then changes of TrkA and TrkB expression were analyzed. RESULTS: In the clinical samples of HNSCC, high expression of TrkA and panTrk were more associated with oropharyngeal and p16 positive squamous cell carcinoma (SCC). In patients with completely resected (R0-resected) oropharyngeal SCC, high TrkA expression was related to superior overall survival and recurrence-free survival (RFS). In patients with R0-resected oral cavity SCC, high panTrk was related to poor RFS. In HPV type E6/E7 gene-transfected FaDu and CAL27 cell lines, increase of TrkA expression was observed. CONCLUSION: It seems that expression pattern of panTrk and TrkA differed according to anatomical sites of HNSCC and was closely related to p16 expression and patient prognosis. Trk expression should be considered in the context of anatomical site, p16 expression or HPV status and Trk subtypes.

Recurrent Indeterminate Dendritic Cell Tumor of the Skin

Indeterminate dendritic cell tumor (IDCT) is a dendritic cell tumor that displays histologic features similar to those of Langerhans cells. The origin of the indeterminate cells may represent precursors of Langerhans cells or skin dendritic cells. IDCT is extremely rare, and tumor progression and predictive factors are not well known. Here, we report a case of a 61-year-old man who presented with a papule on his back and was finally diagnosed with IDCT based on histology and immunohistochemistry. The tumor recurred three months after surgical excision.

Upregulated Neuro-oncological Ventral Antigen 1 (NOVA1) Expression Is Specific to Mature and Immature T- and NK-Cell Lymphomas

BACKGROUND: Recent studies have revealed that the splicing factor neuro-oncological ventral antigen 1 (NOVA1) is enriched in fibroblasts and accumulated T cells of tertiary lymphoid structures. In the present study, we investigated NOVA1 expression in various subtypes of mature and immature T- and natural killer (NK)-cell lymphomas as well as in various B-cell lymphoma subtypes. METHODS: NOVA1 immunoexpression was evaluated in hyperplastic palatine tonsils (n = 20), T- and NK-cell lymphomas (n = 177), diffuse large B-cell lymphomas (n = 151), and other types of B cell lymphomas (n = 31). Nuclear staining intensity and percentage of positive tumor cells were graded. NOVA1 mRNA expression was analyzed in various lymphoma cell lines. RESULTS: Tumor cells of T- and NK-cell lymphomas showed higher expression levels of NOVA1 than did normal paracortical T cells, and 56.5% of T- and NK-cell lymphoma cases showed diffuse and strong expression. The NOVA1 expression level varied according to the subtype; it was higher in angioimmunoblastic T-cell lymphoma, anaplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL), and T lymphoblastic leukemia/lymphoma (T-LBL), but it was lower in ALK-positive ALCL. In almost all B-cell lymphomas, NOVA1 expression was very low or negative. NOVA1 mRNA was also expressed in Jurkat, a T-LBL cell line. CONCLUSIONS: The present findings suggest that NOVA1 upregulation may be involved in certain subtypes of T- and NK-cell lymphomas, but not in B-cell lymphomas. Upregulated NOVA1 expression seems to be a specific biological feature of activated T cells such as T- and NK-cell lymphomas.

Urachal Sinus Presenting with Periumbilicus Abscess / 대한소화기학회지

No abstract available.