Interpretation of PD-L1 expression in gastric cancer: summary of a consensus meeting of Korean gastrointestinal pathologists.

Nivolumab plus chemotherapy in the first-line setting has demonstrated clinical efficacy in patients with human epidermal growth factor receptor 2-negative advanced or metastatic gastric cancer, and is currently indicated as a standard treatment. Programmed death-ligand 1 (PD-L1) expression is an important biomarker for predicting response to anti-programmed death 1/PD-L1 agents in several solid tumors, including gastric cancer. In the CheckMate-649 trial, significant clinical improvements were observed in patients with PD-L1 combined positive score (CPS) ≥ 5, determined using the 28-8 pharmDx assay. Accordingly, an accurate interpretation of PD-L1 CPS, especially at a cutoff of 5, is important. The CPS method evaluates both immune and tumor cells and provides a comprehensive assessment of PD-L1 expression in the tumor microenvironment of gastric cancer. However, CPS evaluation has several limitations, one of which is poor interobserver concordance among pathologists. Despite these limitations, clinical indications relying on PD-L1 CPS are increasing. In response, Korean gastrointestinal pathologists held a consensus meeting for the interpretation of PD-L1 CPS in gastric cancer. Eleven pathologists reviewed 20 PD-L1 slides with a CPS cutoff close to 5, stained with the 28-8 pharmDx assay, and determined the consensus scores. The issues observed in discrepant cases were discussed. In this review, we present cases of gastric cancer with consensus PD-L1 CPS. In addition, we briefly touch upon current practices and clinical issues associated with assays used for the assessment of PD-L1 expression in gastric cancer.

Genetic landscape and PD-L1 expression in Epstein-Barr virus-associated gastric cancer according to the histological pattern.

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer. This study aims to investigate genomic and clinicopathological characteristics of EBVaGC according to the histological pattern. We retrospectively collected 18 specimens of surgically resected EBVaGCs. Whole-exome sequencing was performed for all cases. Moreover, PD-L1 expression and tumor-infiltrating lymphocyte (TIL) percentage were investigated. Among 18 EBVaGCs, 10 cases were of intestinal histology, 3 were of poorly cohesive histology, and the remaining 5 were of gastric carcinoma with lymphoid stroma histology. Whole-exome sequencing revealed that EBVaGCs with intestinal histology harbored pathogenic mutations known to frequently occur in tubular or papillary adenocarcinoma, including TP53, KRAS, FBXW7, MUC6, ERBB2, CTNNB1, and ERBB2 amplifications. One patient with poorly cohesive carcinoma histology harbored a CDH1 mutation. Patients with EBVaGCs with intestinal or poorly cohesive carcinoma histology frequently harbored driver mutations other than PIK3CA, whereas those with EBVaGCs with gastric carcinoma with lymphoid stroma histology lacked other driver mutations. Moreover, the histological pattern of EBVaGCs was significantly associated with the levels of TILs (P = 0.005) and combined positive score (P = 0.027). In conclusion, patients with EBVaGCs with different histological patterns exhibited distinct genetic alteration, PD-L1 expression, and degree of TILs.

Comparison of immunohistochemistry and next-generation sequencing results in oncogenic PTEN missense mutations.

BACKGROUND: Phosphatase and tensin homolog (PTEN) is one of the most frequently mutated tumor suppressor genes in malignant tumors. Oncogenic PTEN mutations have diagnostic, prognostic, and therapeutic implications. Similar to TP53 mutations, oncogenic PTEN mutations can result from nonsynonymous missense mutations. However, there has been no detailed study on the immunostaining pattern of oncogenic PTEN missense mutations. METHODS: We retrospectively selected 18 cancers (13 endometrial cancers, 2 brain tumors, 1 ovarian cancer, 1 lung cancer, and 1 cancer of unknown origin) harboring oncogenic PTEN missense mutations, which were confirmed by targeted next-generation sequencing. PTEN immunohistochemistry was conducted for all cases, and the results were compared with sequencing results. RESULTS: The immunostaining results of PTEN missense mutations revealed a diverse pattern depending on the site of mutation and co-occurring mutation. The most frequent oncogenic PTEN mutations were R130G (4/18, 22.2 %) and R130Q (3/18, 16.7 %). Eleven cases harbored PTEN missense mutations only, whereas the remaining seven cases harbored PTEN truncating mutations and PTEN missense mutations. Complete loss of cytoplasmic expression were found in five cases, of which three had missense mutation only. PTEN R130 residue mutation alone did not showed altered PTEN immunostaining pattern in this study. CONCLUSIONS: PTEN missense mutation, which comprises a portion of oncogenic PTEN mutation, can manifest as a diverse immunostaining pattern. Complementary testing using both immunostaining and next-generation sequencing should be conducted to accurately evaluate the PTEN status in malignancy.

Biomarkers for Predicting Response to Personalized Immunotherapy in Gastric Cancer.

Despite advances in diagnostic imaging, surgical techniques, and systemic therapy, gastric cancer (GC) is the third leading cause of cancer-related death worldwide. Unfortunately, molecular heterogeneity and, consequently, acquired resistance in GC are the major causes of failure in the development of biomarker-guided targeted therapies. However, by showing promising survival benefits in some studies, the recent emergence of immunotherapy in GC has had a significant impact on treatment-selectable procedures. Immune checkpoint inhibitors (ICIs), widely indicated in the treatment of several malignancies, target inhibitory receptors on T lymphocytes, including the programmed cell death protein (PD-1)/programmed death-ligand 1 (PD-L1) axis and cytotoxic T-lymphocyte-associated protein 4 (CTLA4), and release effector T-cells from negative feedback signals. In this article, we review currently available predictive biomarkers (including PD-L1, microsatellite instability, Epstein-Barr virus, and tumor mutational burden) that affect the ICI treatment response, focusing on PD-L1 expression. We further briefly describe other potential biomarkers or mechanisms for predicting the response to ICIs in GC. This review may facilitate the expansion of the understanding of biomarkers for predicting the response to ICIs and help select the appropriate therapeutic approaches for patients with GC.

Gastric cancer with distinct Epstein-Barr virus-positive and -negative tumor components and their whole exome sequencing result: a case Report.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric cancer exhibits distinct clinicopathologic characteristics, showing a good response to immune checkpoint inhibitors and a favorable prognosis. However, gastric cancer comprising distinct EBV-positive and -negative components in a single mass have been rarely reported, and their detailed genetic characteristics have not yet been investigated. Therefore, we reported the case of gastric cancer exhibiting distinct EBV-positive and -negative areas and further investigated its genetic characteristics. CASE PRESENTATIONS: A 70-year-old man underwent distal gastrectomy for gastric cancer, which was detected during a routine health check-up. EBV-encoded RNA in situ hybridization revealed distinct EBV-positive and -negative components at each other's borders, morphologically consistent with collision tumor. We separately sequenced EBV-positive and -negative tumor areas through whole exome sequencing (WES) with matched normal tissue. Remarkably, both EBV-positive and -negative areas shared pathogenic mutations of ARID1A, KCNJ2, and RRAS2. Furthermore, they shared 92 somatic single nucleotide variants and small insertion or deletion mutations, of which 32.7% and 24.5% are EBV-positive and -negative tumor components, respectively. CONCLUSIONS: WES results suggested that gastric cancer with distinct EBV-positive and -negative tumor components, formerly categorized as a collision tumor, can be clonally related. EBV-negative tumor component might be associated with loss of EBV during tumor progression.

Deep Learning Prediction of TERT Promoter Mutation Status in Thyroid Cancer Using Histologic Images.

Background and objectives: Telomerase reverse transcriptase (TERT) promoter mutation, found in a subset of patients with thyroid cancer, is strongly associated with aggressive biologic behavior. Predicting TERT promoter mutation is thus necessary for the prognostic stratification of thyroid cancer patients. Materials and Methods: In this study, we evaluate TERT promoter mutation status in thyroid cancer through the deep learning approach using histologic images. Our analysis included 13 consecutive surgically resected thyroid cancers with TERT promoter mutations (either C228T or C250T) and 12 randomly selected surgically resected thyroid cancers with a wild-type TERT promoter. Our deep learning model was created using a two-step cascade approach. First, tumor areas were identified using convolutional neural networks (CNNs), and then TERT promoter mutations within tumor areas were predicted using the CNN-recurrent neural network (CRNN) model. Results: Using the hue-saturation-value (HSV)-strong color transformation scheme, the overall experiment results show 99.9% sensitivity and 60% specificity (improvements of approximately 25% and 37%, respectively, compared to image normalization as a baseline model) in predicting TERT mutations. Conclusions: Highly sensitive screening for TERT promoter mutations is possible using histologic image analysis based on deep learning. This approach will help improve the classification of thyroid cancer patients according to the biologic behavior of tumors.

Validation and Clinical Application of ONCOaccuPanel for Targeted Next-Generation Sequencing of Solid Tumors.

PURPOSE: Targeted next-generation sequencing (NGS) is widely used for simultaneously detecting clinically informative genetic alterations in a single assay. Its application in clinical settings requires the validation of NGS gene panels. In this study, we aimed to validate a targeted hybridization capture-based DNA panel (ONCOaccuPanel) using the Illumina MiSeq sequencing platform. The panel allows the simultaneous detection of single-nucleotide variants (SNVs), insertions, deletions, and copy number changes of 323 genes and fusions of 17 genes in solid tumors. Materials and Methods: We used 16 formalin-fixed paraffin-embedded (FFPE) tumor samples with previously known genetic mutations and one reference material (HD827) for validation. Moreover, we sequenced an additional 117 FFPE tumor samples to demonstrate the clinical utility of this panel. RESULTS: Validation revealed a 100% positive percentage agreement and positive predictive value for the detection of SNVs, insertions, deletions, copy number changes, fusion genes, and microsatellite instability-high types. We observed high levels of reproducibility and repeatability (R2 correlation coefficients=0.96-0.98). In the limit of detection assessment, we identified all clinically relevant genes with allele frequencies > 3%. Furthermore, the clinical application of ONCOaccuPanel using 117 FFPE samples demonstrated robust detection of oncogenic alterations. Oncogenic alterations and targetable genetic alterations were detected in 98.2% and 27.4% cases, respectively. CONCLUSION: ONCOaccuPanel demonstrated high analytical sensitivity, reproducibility, and repeatability and is feasible for the detection of clinically relevant mutations in clinical settings.

Clinicopathological Characteristics of Advanced Epstein-Barr Virus-associated Gastric Cancer Highlighting Aberrant p53 Expression.

BACKGROUND/AIM: Epstein-Barr virus (EBV)-associated gastric cancer is a distinct subtype of stomach adenocarcinoma. Although previous studies have investigated its clinicopathological characteristics, there is a lack of research focusing on advanced EBV-associated gastric cancer. In this study, we performed a comprehensive review of advanced EBV-associated gastric cancer cases. PATIENTS AND METHODS: We retrospectively collected 18 consecutive cases of surgically resected advanced EBV-associated gastric cancer. Clinicopathological parameters were investigated using histological review, immunohistochemistry, and a review of the electronic medical records of the hospital. RESULTS: The predominant histological pattern of advanced EBV-associated gastric cancer, according to the Laurén classification, was intestinal-type adenocarcinoma with varying degrees of differentiation. However, focal areas showing conventional gastric carcinoma with a lymphoid stromal pattern were found in all cases except one. In addition to the previously described histological patterns of EBV-associated gastric cancer, one case displayed chronic granulomatous inflammation-like histology with barely identifiable malignant epithelial cells. Another case had a pure signet-ring cell carcinoma component showing nuclear positivity for the EBV-encoded RNA in situ hybridization assay. Remarkably, five out of 18 cases (27.8%) showed aberrant p53 expression on immunostaining, which is known to occur rarely in EBV-associated gastric cancer. All cases with aberrant p53 expression had intestinal-type adenocarcinoma-like components. CONCLUSION: Advanced EBV-associated gastric cancer had distinct histology and a higher rate of aberrant p53 immunostaining pattern than conventional EBV-associated gastric cancer. Therefore, their biological behavior should be investigated separately.

Molecular Pathology of Gastric Cancer.

Gastric cancer (GC) is one of the most common lethal malignant neoplasms worldwide, with limited treatment options for both locally advanced and/or metastatic conditions, resulting in a dismal prognosis. Although the widely used morphological classifications may be helpful for endoscopic or surgical treatment choices, they are still insufficient to guide precise and/or personalized therapy for individual patients. Recent advances in genomic technology and high-throughput analysis may improve the understanding of molecular pathways associated with GC pathogenesis and aid in the classification of GC at the molecular level. Advances in next-generation sequencing have enabled the identification of several genetic alterations through single experiments. Thus, understanding the driver alterations involved in gastric carcinogenesis has become increasingly important because it can aid in the discovery of potential biomarkers and therapeutic targets. In this article, we review the molecular classifications of GC, focusing on The Cancer Genome Atlas (TCGA) classification. We further describe the currently available biomarker-targeted therapies and potential biomarker-guided therapies. This review will help clinicians by providing an inclusive understanding of the molecular pathology of GC and may assist in selecting the best treatment approaches for patients with GC.

Evaluation of the characteristics of multiple human papillomavirus (HPV) infections identified using the BD Onclarity HPV assay and comparison with those of single HPV infection.

BACKGROUND: Human papillomavirus (HPV) infection is a major cause of cervical cancer and associated precursor lesions. Multiple HPV genotype infections have been reported. However, their clinicopathological characteristics still remain elusive. METHODS: For this study, 814 consecutive patients who had undergone colposcopy and HPV genotyping test using BD Onclarity HPV assay were retrospectively selected. Clinicopathological parameters of multiple HPV infections were compared with those of single HPV infection. RESULTS: Multiple HPV infections were found in 110 out of 814 cases (13.5%). Multiple HPV infections were associated with a significantly higher incidence of high-grade intraepithelial lesions (HSILs) compared with single HPV infection. Other high-risk HPV genotypes, in addition to HPV 16, were found more frequently in the multiple HPV infections group; these included HPV 51, 52, 33/58, 56/59/66, and 35/39/68. No specific coinfection pattern was not identified. Additionally, the number of HPV genotypes in multiple HPV infections was not associated with the progression to HSIL or squamous cell carcinoma. CONCLUSIONS: Multiple HPV infections have distinct clinicopathological characteristics (compared with single HPV infection). As their biological behavior is uncertain, close and frequent follow-up is warranted.

Strategic Significance of Low Viral Load of Human Papillomavirus in Uterine Cervical Cytology Specimens.

Infection with high-risk (HR) Human Papillomavirus (HPV) is associated with the development of precancerous lesions or invasive carcinoma of the uterine cervix. Thus, the high viral load (VL) of HR-HPV DNA currently serves as a representative quantitative marker for cervical cancer. However, the clinical significance of low HPV DNA VL remains undetermined. This study aimed to evaluate the clinical association between the low HPV DNA VL and cytology/histologic diagnosis of cervical samples. We searched the electronic medical databases for the resultant analyses of HPV genotyping among patients who underwent treatment for any cervical lesion or who had undergone gynecological examinations with any positive HPV results according to the national cancer screening service between 2015 and 2016. HPV testing with genotyping and semi-quantitative VL measurement was conducted using an AnyplexTM II H28 Detection assay (H28 assay, Seegene, Seoul, Republic of Korea). The H28 assay is a multiplex semi-quantitative real-time PCR test using the tagging of oligonucleotide cleavage and extension (TOCE) technology. The VL was semi-quantified as high (3+; positive signal before 31 PCR cycles), intermediate (2+; positive between 31 and 39 PCR cycles), or low (1+; positive after 40 PCR cycles). Out of 5940 HPV VL analyses, 356 assays (5.99%) were reported as low VL (1+) of HPV DNA. Matched cytology diagnoses were mostly negative findings (n = 347, 97.5%), except for seven cases of atypical squamous cells of undetermined significance (1.9%) and two cases of atypical glandular cells (0.6%). During the follow-up periods, abnormal cytologic diagnoses were identified, including one case of high-grade squamous intraepithelial lesion (HSIL) and two low-grade squamous intraepithelial lesions (LSILs). The matched, confirmative histologic diagnosis of HSIL cytology was compatible with chronic inflammation, wherein the two LSILs had regular check-ups. None revealed clinically concerned outcomes associated with HPV-related squamous lesions. The cytology was most likely negative for malignancy when the VL of HPV DNA was low (1+). Additional strategic monitoring and management may thus be unnecessary.

Novel Animal Model of Spontaneous Cerebral Petechial Hemorrhage Using Focused Ultrasound in Rats.

Background and Objectives: Petechial cerebral hemorrhages can be caused by various factors, such as traumas, cerebral infarctions, and aging, and is related to the disruption of the blood-brain barrier or the cellular damage of blood vessels. However, there is no animal model that recapitulates cerebral petechial hemorrhages. Materials and Methods: Here, we implemented a petechial hemorrhage using a novel technology, i.e., microbubble-assisted focused ultrasound (MB + FUS). Results: This method increases the permeability of the blood-brain barrier by directly applying mechanical force to the vascular endothelial cells through cavitation of the microbubbles. Microbubble-enhanced cavitation has the advantage of controlling the degree and location of petechial hemorrhages. Conclusions: We thus generated a preclinical rat model using noninvasive focal MB + FUS. This method is histologically similar to actual petechial hemorrhages of the brain and allows the achievement of a physiologically resembling petechial hemorrhage. In the future, this method shall be considered as a useful animal model for studying the pathophysiology and treatment of petechial cerebral hemorrhages.

Comparison of Seegene Anyplex II HPV28 assay with BD Onclarity HPV assay for human papillomavirus genotyping.

Presently, human papillomavirus (HPV)-based cervical cancer screening is commonly used and is replacing conventional cytology screening tests. The HPV genotyping assay is useful for triage in cervical cancer screening and the evaluation of HPV vaccination effects. In this study, we evaluated the clinical performance of two HPV genotyping assays, BD Onclarity HPV (Onclarity) and Seegene Anyplex II HPV28 (Anyplex) in the detection of relevant cervical lesions and for HPV genotyping concordance. Anyplex and Onclarity assays were performed on 920 consecutive liquid-based specimens. Anyplex, sensitivity, specificity, and genotyping concordance with Onclarity were optimal when restricted to ≥2+ (medium) viral loads. HPV genotyping agreement between the two assays ranged between 0.75 and 0.9 (excellent), except for HPV 33/58, which was 0.73 (good). With Onclarity as a reference, the relative sensitivity of Anyplex for the detection of ≥CIN 2 was 1.05 (95% CI: 0.99-1.1) and the relative specificity for detection of negative for intraepithelial lesion and malignancy (NILM) was 0.89 (95% CI: 0.85-0.93). For most ≥CIN 2 lesions, high-risk HPV was detected by Onclarity (66/72) and Anyplex (69/72) assays. For high-risk HPV negative ≥CIN 2 lesions, possible high-risk HPV genotypes were detected by Anyplex. In conclusion, the genotyping agreement between the tests was good to excellent. Full genotyping with Anyplex might confer additional benefits to patients with ≥CIN 2, although the difference is small. We also suggest an optimal cutoff value when reporting HPV infections using the Anyplex assay (≥2+; medium viral loads).

Clinical Utility of Next-generation Sequencing in Real-world Cases: A Single-institution Study of Nine Cases.

BACKGROUND/AIM: Targeted next-generation sequencing (NGS) is a well-established technique to detect pathogenic alterations in tumors. Indeed, it is the cornerstone of targeted therapy in precision medicine. We investigated the clinical utility of next-generation sequencing in real-world cases. PATIENTS AND METHODS: We retrospectively selected six representative cancer cases, wherein targeted NGS played a pivotal role in the diagnosis and treatment of patients. Additionally, we analyzed three cases with rare, unusual pathogenic alterations. RESULTS: Our NGS analysis revealed that four patients had TPR-ROS1, EGFR-RAD51, and NCOA4-RET fusions and MET exon 14 skipping mutation, respectively, which can be treated with targeted therapy. Furthermore, we used NGS as a diagnostic tool to confirm the origin of unknown primary malignant tumors in two cases. Interestingly, NGS also helped us identify the following cases: patients exhibiting BRCA1 and TP53 mutations that exhibited histological and immunohistochemical characteristics consistent with endometrioid carcinoma, patients with high-grade serous carcinoma not possessing a TP53 mutation, and patients with small cell lung cancer with a ERBB2 mutation and displaying no loss of RB1. CONCLUSION: We recommend targeted NGS for the diagnoses and targeted therapy of cancer patients.

Expression of ICAM-1 in Blood Vascular Endothelium and Tissues in Human Premalignant Lesion and Gastric/Hepatocellular Carcinomas.

Background/Aims: Angiogenesis is essential for the outgrowth and metastasis of tumors. The structure and characteristics of tumor vasculature differ from those of normal vessels. We compared the characteristics of differentially expressed genes in endothelial cells (ECs) isolated from gastric and normal cells. Methods: Previously, we had isolated pure tumor ECs (TECs) and normal ECs (NECs) from advanced gastric cancer (AGC) lesions and normal mucosal tissues, respectively. Using the oligomer chip platform of the Affymetrix GeneChip technology, genes that were expressed more than three-fold with a significance of p≤0.001 were measured. The intercellular adhesion molecule 1 (ICAM-1) was found to be overexpressed in the TECs compared to the normal gastric ECs. In this study, the upregulation of ICAM-1 was confirmed in cultured TECs by immunofluorescence. Results: The expression of ICAM-1 was upregulated in the ECs, as well as in the stromal and immune cells, in early human gastric preneoplastic and hepatic fibrotic tissues. Upregulation of ICAM-1 was observed in the TECs, immune cells, and cancer epithelial cells in AGC and hepatocellular carcinoma (HCC). These results suggest that increased ICAM-1 expression in the ECs of the tissue microenvironment progressively contributes to the recruitment of immune cells to promote inflammation, leading to fibrosis and tumorigenesis. Conclusions: Therefore, upregulated ICAM-1 in the tissues in premalignant gastric diseases or hepatic fibrosis and their malignant cancers could be a promising target for disease prevention and treatment.

Genomic Profiling of Aggressive Thyroid Cancer in Association With its Clinicopathological Characteristics.

BACKGROUND/AIM: Poorly differentiated thyroid carcinoma (PDTC), anaplastic thyroid carcinoma (ATC), and advanced DTC have poor outcomes. MATERIALS AND METHODS: We performed next-generation sequencing in nine selected aggressive thyroid cancers. RESULTS: Among the nine patients, the driver gene mutations BRAF V600E (3/9) and NRAS Q61K (1/9) were detected. Other oncogenic mutations included ERBB2 (1/9) and CDK4 (1/9). Telomerase reverse transcriptase (TERT) promoter mutation was found in five cases. Among tumor suppressor genes, mutations in TP53 (3/9), ARID1A (1/9), APC (1/9), MEN1 (1/9), DICER1 (1/9), and MED12 (1/9) were identified. RET fusions were found in two cases, one with PTDC and the other with ATC. The ATC with RET fusion also harbored TP53 and TERT promoter mutations. None of the PDTC cases had BRAF or RAS gene alterations. CONCLUSION: Since genetic alterations with therapeutic and prognostic implications were detected using next-generation sequencing, this technique is recommended to be performed for patients with aggressive thyroid cancer.

Genomic characteristics of invasive mucinous adenocarcinoma of the lung with multiple pulmonary sites of involvement.

Invasive mucinous adenocarcinoma (IMA) of the lung frequently presents with diffuse pneumonic-type features or multifocal lesions, which are regarded as a pattern of intrapulmonary metastases. However, the genomics of multifocal IMAs have not been well studied. We performed whole exome sequencing on samples taken from 2 to 5 regions in seven patients with synchronous multifocal IMAs of the lung (24 regions total). Early initiating driver events, such as KRAS, NKX2-1, TP53, or ARID1A mutations, are clonal mutations and were present in all multifocal IMAs in each patient. The tumor mutational burden of multifocal IMAs was low (mean: 1.13/mega base), but further analyses suggested intra-tumor heterogeneity. The mutational signature analysis found that IMAs were predominantly associated with endogenous mutational process (signature 1), APOBEC activity (signatures 2 and 13), and defective DNA mismatch repair (signature 6), but not related to smoking signature. IMAs synchronously located in the bilateral lower lobes of two patients with background usual interstitial pneumonia had different mutation types, suggesting that they were double primaries. In conclusion, genomic evidence found in this study indicated the clonal intrapulmonary spread of diffuse pneumonic-type or multifocal IMAs, although they can occur in multicentric origins in the background of usual interstitial pneumonia. IMAs exhibited a heterogeneous genomic landscape despite the low somatic mutation burden. Further studies are warranted to determine the clinical significance of the genomic characteristics of IMAs in expanded cohorts.

Association of MGMT Gene Promoter Methylation With Clinicopathological Parameters in Patients With Wild-type IDH Glioblastoma.

BACKGROUND: The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter plays a key role in response to temozolomide chemotherapy and disease prognosis in patients with wild-type isocitrate dehydrogenase (IDH) glioblastoma (GBM). PATIENTS AND METHODS: The MGMT promoter methylation status and its association with clinicopathological parameters were retrospectively analysed in a cohort of 316 patients with GBM with wild-type IDH. RESULTS: MGMT methylation was significantly associated with ATRX chromatin remodeler (ATRX) loss and completion of the standard Stupp protocol. The median durations of overall and progression-free survival for the unmethylated, low-methylated (10-39%), and hypermethylated (≥40%) groups were 15, 23, and 30 months and 11, 18, and 21 months, respectively. However, the improvement in the survival of the hypermethylated group was not statistically significant. CONCLUSION: We suggest a possible association between MGMT methylation status and ATRX mutations in GBM with wild-type IDH.

Multiple Human Papilloma Virus (HPV) Infections Are Associated with HSIL and Persistent HPV Infection Status in Korean Patients.

Infections with multiple human papilloma virus (HPV) types have been reported, but their role in cervical carcinogenesis has not been fully elucidated. In this study, 236 cases with multiple HPV infection were examined and compared to 180 cases with single HPV infection. HPV genotyping was performed with cervico-vaginal swab specimens using multiplex (real-time) polymerase chain reaction (PCR). In multiple HPV infection, the most prevalent HPV genotype was HPV 53, followed by HPV 16, 58, 52, and 68. HPV 33, 35, 39, 51, 52, 53, 58, and 68 were high-risk-HPV (HR-HPV) genotypes that were more frequently detected in multiple HPV infection compared to that in single HPV infection. The association between multiple HPV infection and high-grade SIL (HSIL) was significantly stronger compared to that of single HPV infection and HSIL (p = 0.002). Patients with multiple HPV infection displayed persistent and longer duration of the HPV infection compared to patients with single HPV infection. Multiple HPV infections have distinct clinicopathologic characteristics. Since it is associated with persistent HPV infection, HSIL, and different HR-HPV strains in contrast to single HPV infection, the presence of multiple HPV infection should be reported; close follow up is warranted.

HNF-1ß as an immunohistochemical marker for distinguishing chromophobe renal cell carcinoma and hybrid oncocytic tumors from renal oncocytoma.

The histologic features of renal oncocytoma (RO) are similar to those for the more aggressive chromophobe renal cell carcinoma (ChRCC). To assess immunohistochemical markers of the two, the sensitivity and specificity of cytokeratin 7 (CK7) and C-kit, as well as hepatocyte nuclear factor-1ß (HNF-1ß), were analyzed. Typical cases of ChRCC and RO at Severance Hospital between July 2014 and July 2018 were selected retrospectively. Among 44 cases, 17 were unanimously compatible with ChRCC, 16 were RO, and 11 cases were indeterminate. Samples from all selected cases were used for immunostaining with antibodies against CK7, C-kit, HNF-1ß, and CD10. Immunostaining demonstrated complete loss of HNF-1ß expression in 11 out of 17 (64.7%) ChRCC cases and a partial, but significant loss in > 50% of tumor cells in the remaining 6 cases (35.3%). In contrast, HNF-1ß expression was preserved in tumor cells of RO cases. Fourteen of 17 ChRCC cases (82.4%) were diffusely positive for CK7, whereas cases of RO were focal positive or negative. C-kit staining did not show a significant difference between ChRCC and RO. Two of five ChRCC cases showing diffuse immunoreactivity for CD10 had poor prognoses of local invasion, distant metastasis, or death. Loss of HNF-1ß expression is a useful marker with which to diagnose ChRCC, especially in cases with confusing histologic findings or equivocal CK7 staining. Additionally, CD10 staining in high-grade ChRCC aids in diagnosis and prediction of the clinical prognosis.