Pathologic characteristics of histiocytic and dendritic cell neoplasms

Histiocytic and dendritic cell neoplasms comprise diverse tumors originating from the mononuclear phagocytic system, which includes monocytes, macrophages, and dendritic cells. The 5th edition of the World Health Organization (WHO) classification updating the categorization of these tumors, reflecting a deeper understanding of their pathogenesis.In this updated classification system, tumors are categorized as Langerhans cell and other dendritic cell neoplasms, histiocyte/macrophage neoplasms, and plasmacytoid dendritic cell neoplasms. Follicular dendritic cell neoplasms are classified as mesenchymal dendritic cell neoplasms within the stroma-derived neoplasms of lymphoid tissues.Each subtype of histiocytic and dendritic cell neoplasms exhibits distinct morphological characteristics. They also show a characteristic immunophenotypic profile marked by various markers such as CD1a, CD207/langerin, S100, CD68, CD163, CD4, CD123, CD21, CD23, CD35, and ALK, and hematolymphoid markers such as CD45 and CD43. In situ hybridization for EBV-encoded small RNA (EBER) identifies a particular subtype. Immunoprofiling plays a critical role in determining the cell of origin and identifying the specific subtype of tumors. There are frequent genomic alterations in these neoplasms, especially in the mitogen-activated protein kinase pathway, including BRAF (notably BRAF V600E), MAP2K1, KRAS, and NRAS mutations, and ALK gene translocation.This review aims to offer a comprehensive and updated overview of histiocytic and dendritic cell neoplasms, focusing on their ontogeny, morphological aspects, immunophenotypic profiles, and molecular genetics. This comprehensive approach is essential for accurately differentiating and classifying neoplasms according to the updated WHO classification.

A phase II open-label randomized clinical trial of preoperative durvalumab or durvalumab plus tremelimumab in resectable head and neck squamous cell carcinoma

PURPOSE

Clinical implications of neoadjuvant immunotherapy in patients with locally advanced but resectable head and neck squamous cell carcinoma (HNSCC) remain largely unexplored.

PATIENTS AND METHODS

Patients with resectable HNSCC were randomized to receive a single dose of preoperative durvalumab (D) with or without tremelimumab (T) before resection, followed by postoperative (chemo)radiation based on multidisciplinary discretion and 1-year D treatment. Artificial intelligence (AI)-powered spatial distribution analysis of tumor-infiltrating lymphocytes and high-dimensional profiling of circulating immune cells tracked dynamic intratumoral and systemic immune responses.

RESULTS

Of the 48 patients enrolled (D: 24 patients, D+T: 24 patients), 45 underwent surgical resection per protocol (D: 21 patients; D+T: 24 patients). D+/-T had a favorable safety profile and did not delay surgery. Distant recurrence-free survival (DRFS) was significantly better in patients treated with D+T than in those treated with D monotherapy. AI-powered whole-slide image analysis demonstrated that D+T significantly reshaped the tumor microenvironment toward immune-inflamed phenotypes, in contrast to D monotherapy or cytotoxic chemotherapy. High-dimensional profiling of circulating immune cells revealed a significant expansion of T cell subsets characterized by proliferation and activation in response to D+T therapy, which was rare following D monotherapy. Importantly, expansion of specific clusters in CD8+ T cells and non-regulatory CD4+ T cells with activation and exhaustion programs was associated with prolonged DRFS in patients treated with D+T.

CONCLUSIONS

Preoperative D+/-T is feasible and may benefit patients with resectable HNSCC. Distinct changes in the tumor microenvironment and circulating immune cells were induced by each treatment regimen, warranting further investigation.

Diagnosis of Primary Ciliary Dyskinesia via Whole Exome Sequencing and Histologic Findings

PURPOSE

To assess the diagnostic potential of whole-exome sequencing (WES) and elucidate the clinical and genetic characteristics of primary ciliary dyskinesia (PCD) in the Korean population.

MATERIALS AND METHODS

Forty-seven patients clinically suspected of having PCD were enrolled at a tertiary medical center. WES was performed in all patients, and seven patients received biopsy of cilia and transmission electron microscopy (TEM).

RESULTS

Overall, PCD was diagnosed in 10 (21.3%) patients: eight by WES (8/47, 17%), four by TEM. Among patients diagnosed as PCD based on TEM results, two patients showed consistent results with WES and TEM of PCD (2/4, 50%). In addition, five patients, who were not included in the final PCD diagnosis group, had variants of unknown significance in PCD-related genes (5/47, 10.6%). The most frequent pathogenic (P)/likely pathogenic (LP) variants were detected in DNAH11 (n=4, 21.1%), DRC1 (n=4, 21.1%), and DNAH5 (n=4, 21.1%). Among the detected 17 P/LP variants in PCD-related genes in this study, 8 (47.1%) were identified as novel variants. Regarding the genotype-phenotype correlation in this study, the authors experienced severe PCD cases caused by the LP/P variants in MCIDAS, DRC1, and CCDC39.

CONCLUSION

Through this study, we were able to confirm the value of WES as one of the diagnostic tools for PCD, which increases with TEM, rather than single gene tests. These results will prove useful to hospitals with limited access to PCD diagnostic testing but with relatively efficient in-house or outsourced access to genetic testing at a pre-symptomatic or early disease stage.

Clinical Practice Recommendations for the Use of Next-Generation Sequencing in Patients with Solid Cancer: A Joint Report from KSMO and KSP

In recent years, next-generation sequencing (NGS)-based genetic testing has become crucial in cancer care. While its primary objective is to identify actionable genetic alterations to guide treatment decisions, its scope has broadened to encompass aiding in pathological diagnosis and exploring resistance mechanisms. With the ongoing expansion in NGS application and reliance, a compelling necessity arises for expert consensus on its application in solid cancers. To address this demand, the forthcoming recommendations not only provide pragmatic guidance for the clinical use of NGS but also systematically classify actionable genes based on specific cancer types. Additionally, these recommendations will incorporate expert perspectives on crucial biomarkers, ensuring informed decisions regarding circulating tumor DNA panel testing.

Genetic characteristics of advanced oral tongue squamous cell carcinoma in young patients

OBJECTIVES

We aimed to investigate genetic alterations in oral tongue squamous cell carcinoma (OTSCC) based on age and the clinical significance of these alterations in young OTSCC patients.

MATERIALS AND METHODS

We detected genetic alterations in 44 cases of advanced OTSCC through next-generation sequencing and analyzed and compared patients either younger or older than 45 years. Further analysis was conducted on a validation group of 96 OTSCC patients aged ≤ 45 years to examine the clinical and prognostic associations of TERT promoter (TERTp) mutations.

RESULTS

TP53 mutation was the most common genetic alteration in advanced OTSCC (88.6%), followed by TERTp mutation (59.1%), CDKN2A mutation (31.8%), FAT1 mutation (9.1%), NOTCH1 mutation (9.1%), EGFR amplification (18.2%), and CDKN2A homozygous deletion (4.5%). TERTp mutation was the only genetic alteration significantly enriched in young patients (81.3% in young versus 46.4% in older; P < 0.024). Within the validation group of young patients, TERTp mutation was identified in 30 cases (30/96, 31.3%) and tended to be related to both smoking and alcohol consumption (P = 0.072), higher stage (P = 0.002), more frequent perineural invasion (P = 0.094), and worse overall survival (P = 0.012) than wild type.

CONCLUSION

Our findings suggest that TERTp mutation is more frequent in young patients with advanced OTSCC and is associated with worse clinical outcomes. Therefore, TERTp mutation may serve as a prognostic biomarker for OTSCC in young patients. The findings of this study may help in developing personalized treatment strategies for OTSCC based on age and genetic alterations.

Clinicopathologic characterization of cervical metastasis from an unknown primary tumor: a multicenter study in Korea

BACKGROUND

Research regarding cervical metastasis from an unknown primary tumor (CUP) according to human papillomavirus (HPV) and Epstein-Barr virus (EBV) status in Korea has been sporadic and small-scale. This study aims to analyze and understand the characteristics of CUP in Korea according to viral and p16 and p53 status through a multicenter study.

METHODS

Ninety-five cases of CUP retrieved from six hospitals in Korea between January 2006 and December 2016 were subjected to high-risk HPV detection (DNA in situ hybridization [ISH] or real-time polymerase chain reaction), EBV detection (ISH), and immunohistochemistry for p16 and p53.

RESULTS

CUP was HPV-related in 37 cases (38.9%), EBV-related in five cases (5.3%), and unrelated to HPV or EBV in 46 cases (48.4%). HPV-related CUP cases had the best overall survival (OS) (p = .004). According to the multivariate analysis, virus-unrelated disease (p = .023) and longer smoking duration (p < .005) were prognostic factors for poor OS. Cystic change (p = .016) and basaloid pattern (p < .001) were more frequent in HPV-related cases, and lymphoepithelial lesion was frequent in EBV-related cases (p = .010). There was no significant association between viral status and p53 positivity (p = .341), smoking status (p = .728), or smoking duration (p = .187). Korean data differ from Western data in the absence of an association among HPV, p53 positivity, and smoking history.

CONCLUSIONS

Virus-unrelated CUP in Korea had the highest frequency among all CUP cases. HPV-related CUP is similar to HPV-mediated oropharyngeal cancer and EBVrelated CUP is similar to nasopharyngeal cancer in terms of characteristics, respectively.

Investigation of somatic mutation profiles and tumor evolution of primary oropharyngeal cancer and sequential lymph node metastases using multiregional whole-exome sequencing

Lymph node (LN) metastasis is an important factor in determining the treatment and prognosis of oropharyngeal squamous cell carcinoma (OPSCC). Here, we compared the somatic mutational profiles and clonal evolution of primary and metastatic LNs using multiregion sequencing of human papilloma virus (HPV)-positive OPSCC and HPV-negative OPSCC. We performed high-depth whole-exome sequencing (200×) of 76 samples from 18 patients with OPSCC (10 HPV-positive and 8 HPV-negative), including 18 primary tumor samples, 40 metastatic LN samples, and 18 normal tissue samples. Among 40 metastatic LNs, 22 showed extranodal extension (ENE). Mutation profiles of HPV-positive OPSCC and HPV-negative OPSCC were similar to those reported previously. Somatic mutations in CDKN2A and TP53 were frequently detected in HPV-negative OPSCC. Somatic mutations in HPV-positive OPSCC samples showed APOBEC-related signatures. Somatic mutations from metastatic LNs showed a different pattern than the primary tumor. Somatic mutations acquired in the WNT pathway during metastasis showed a significant relationship with ENE. Clonal evolution analysis of primary and metastatic LNs showed that, in some cases, each metastatic LN originated from a different primary tumor sub-clone.

Role of postoperative radiotherapy in resected adenoid cystic carcinoma of the head and neck

PURPOSE

Although postoperative radiotherapy (PORT) is demonstrably effective in local control of head and neck adenoid cystic carcinoma (HNACC), its application is controversial and the subset of patients who would benefit most from PORT is unknown. Herein, we analyzed the data of HNACC patients to clarify the role of PORT.

METHODS

We retrospectively reviewed 187 patients with nonmetastatic HNACC who underwent surgical resection between 2005 and 2019. The study endpoints were locoregional failure-free survival (LRFFS), progression-free survival (PFS), and overall survival (OS). Subgroup analysis and recursive partitioning analysis (RPA) were performed to identify patients most likely to benefit from PORT.

RESULTS

With a median follow-up of 84.7 months, the 5-year LRFFS, PFS, and OS were 70.0%, 52.6%, and 86.4%, respectively. Survival was significantly shorter in patients who experienced local failure than in those who did not (5-year OS: 88.1% vs. 80.5%, P = 0.001). The local failure rate was significantly lower in patients who underwent PORT (16.9% vs. 31.0%, P = 0.021), despite the high frequency of adverse factors. Especially, significant decreases in local failure and similar OS rates could be obtained after PORT among patients with positive margins, T2-4 stage disease, and minor salivary gland tumors. The RPA model for PFS categorized patients into four groups according to three prognostic factors (T-stage, location, and sex). The RPA model for LRFFS and OS suggested three groups based on two factors (T-stage, margin for LRFFS; T-stage, grade 3 for OS).

CONCLUSION

PORT could prevent dismal survival, while significantly reducing local failures in high-risk HNACC patients.

Characterizing intrinsic molecular features of the immune subtypes of salivary mucoepidermoid carcinoma

INTRODUCTION

Characterizing the tumor microenvironment (TME) and immune landscape of cancer has been a promising step towards discovering new therapeutic biomarkers and guiding precision medicine; however, its application in mucoepidermoid carcinoma (MEC) has been sparse. Here, we conducted a comprehensive study to understand the properties of the TME and immune profiles of MEC.

METHOD

20 patients with MEC were collected from Yonsei Head and Neck Cancer Centre, Yonsei University, South Korea. Total RNA sequencing was conducted to determine gene expression profiles. Bioinformatic and immunoinformatic analyses were applied to characterize the TME and identify immunophenotypic subgroups, and to investigate the molecular features that explain the distinct phenotypes.

RESULTS

The MEC samples were subdivided into two groups, immune hot and immune cold, based on the heterogenous immune cell-infiltration and activation level. The immune-hot subgroup exhibited a higher level of immune activity, including T cell infiltration, cytolytic score, IFN-γ, antigen-presenting machinery, and immune modulator genes. Further characterizing molecular features of two subgroups, downregulation of lipid metabolic regulators, including MLXIPL and FASN, and the migration of chemokines and leukocytes were observed, respectively. And, Group-specific expression of immune checkpoint molecules, such as TIGIT, PD-L2, and CTLA-4, was observed in the immune-hot group, which can be exploited as a potential immunotherapeutic biomarker.

CONCLUSIONS

Immunophenotypically heterogeneous MEC subgroups analysis has shown distinctive molecular characteristics and provided potential treatment options. These findings yield new insights into TME of MEC and may help next step to study this uncharted cancer.

Primary Gastrointestinal T/NK Cell Lymphoma

Primary gastrointestinal T/NK cell lymphoma (GI-TNKL) is an uncommon and heterogeneous group of lymphoid malignancies. We aimed to investigate their subtype distribution, clinicopathologic characteristics, and clinical outcomes. A total of 38 GI-TNKL cases and their clinical and pathological characteristics were analyzed. GI-TNKL occurred in adults with a median patient age in the sixth decade of life and showed a slight male predominance. The most common histologic type was extranodal NK/T-cell lymphoma, nasal type (ENKTL; 34.2%), followed by monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL; 31.6%), intestinal T-cell lymphoma, NOS (ITCL, NOS, 18.4%), anaplastic large cell lymphoma, ALK-negative (ALCL, ALK-; 13.2%). The small intestine was the primary affected region. More than 90% of patients complained of various GI symptoms and cases with advanced Lugano stage, high IPI score, or bowel perforation that required emergent operation were not uncommon. GI-TNKL also showed aggressive behavior with short progression-free survival and overall survival. This thorough clinical and pathological descriptive analysis will be helpful for accurate understanding, diagnosis, and treatment.

Human herpesvirus 8-negative effusion-based lymphoma with indolent clinical behavior in an elderly patient: A case report and literature review

Primary effusion lymphoma (PEL) is a B-cell non-Hodgkin's lymphoma that is usually characterized by lymphomatous effusions in the body cavity without any detectable tumor masses. According to the World Health Organization (WHO) schema for tumor classification, PEL is defined by the presence of human herpesvirus 8 (HHV8) in malignant lymphoid cells. However, a subset of effusion-based B-cell lymphoma is not HHV8-positive and exhibits different clinicopathological characteristics. The 2017 WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues does not list HHV8-negative effusion-based lymphoma, which remains an underappreciated B-cell lymphoma, as an individual entity. The present study reports a case of this rare type of lymphoma with indolent clinical behavior in a 75-year-old male patient receiving only symptomatic treatment. Additionally, a review of similar cases reported in the English literature is presented.

Descriptive Analysis of Histiocytic and Dendritic Cell Neoplasms: A Single-Institution Experience

PURPOSE

Histiocytic and dendritic cell neoplasms are rare hematologic tumors. This study aimed to describe the epidemiologic features of the entire spectrum of histiocytic and dendritic cell neoplasms, including clinicopathological variables and patient outcomes.

MATERIALS AND METHODS

We comprehensively reviewed 274 patients who were diagnosed with histiocytic and dendritic neoplasms at Severance Hospital, Seoul, South Korea between 1995 and 2018.

RESULTS

The most common neoplasm was Langerhans cell histiocytosis (LCH), followed by dermal xanthogranuloma. Among non-LCH sarcomas, histiocytic sarcoma (HS) showed a relatively high prevalence, followed by follicular dendritic cell sarcoma (FDCS). Disseminated juvenile xanthogranuloma (DJG), Erdheim-Chester disease (ECD), indeterminate dendritic cell tumor (IDCT), and interdigitating dendritic cell sarcoma (IDCS) rarely occurred. Generally, these tumors presented in childhood, although the non-LCH sarcoma (HS/FDCS/IDCS/IDCT) group of tumors and ECD occurred in late adulthood. Multiorgan involvement and advanced Ann-Arbor stage, as well as recurrence and death of disease, were not uncommon. The non-LCH sarcoma group had the worst overall survival, compared to the DJG, ECD, and LCH groups.

CONCLUSION

Our findings indicate that histiocytic and dendritic cell neoplasms exhibit heterogeneous epidemiologic characteristics and that some patients may have unfavorable outcomes, especially those with non-LCH sarcoma.

Forkhead Box C1 (FOXC1) Expression in Stromal Cells within the Microenvironment of T and NK Cell Lymphomas: Association with Tumor Dormancy and Activation

PURPOSE

Forkhead box C1 (FOXC1) is critical for maintaining bone marrow microenvironments during hematopoiesis, but its role in hematological malignancies remains obscure. Here, we investigated whether FOXC1 regulates tumor dormancy and activation in the microenvironments of T and natural killer (NK) cell lymphomas.

Materials and Methods

One hundred and twenty cases of T and NK cell lymphomas were included; the immunohistochemical expression of FOXC1 was investigated in stromal cells, and numbers of FOXC1+ stromal cells were counted. Furthermore, the expression of phosphorylated p38 (p-p38) and phosphorylated ERK1/2 (p-ERK1/2) in tumor cells was investigated using immunohistochemistry.

RESULTS

FOXC1 was variably expressed in C-X-C motif chemokine 12-associated reticular stromal cells, histiocytes, (myo)fibroblasts, and endothelial cells. The phenotypes of cases were categorized as dormant (high p-p38/low p-ERK1/2; n=30, 25.0%), active (high p-ERK1/2/low p-p38; n=25, 20.8%), or intermediate (others; n=65, 54.2%). Lower FOXC1+ stromal cell infiltration was associated with the dormant phenotype, the precursor T lymphoblastic leukemia/lymphoma subtype, and inferior overall survival rates, whereas higher FOXC1+ stromal cell infiltration was associated with the active phenotype and favorable patient prognosis (p < 0.05 for all).

CONCLUSION

These results suggested that FOXC1+ stromal cells within the microenvironments of T and NK cell lymphomas might be related to tumor phenotypes.

Clinical-pathological prognostic factors and treatment failure patterns in T1-2 high-grade parotid gland cancer

OBJECTIVES

The purpose of this study was to evaluate the treatment outcomes of patients with T1-2, high-grade parotid cancer, and to analyze the prognostic factors and treatment failure patterns.

MATERIALS AND METHODS

Of the 101 patients who were diagnosed with high-grade parotid cancer from March 2003 to December 2018, a total of 39 males and 23 females who had T1-2 tumor were enrolled in this study.

RESULTS

The average follow-up period of patients in this study was 63.9 months. The 5-year overall survival rate was 73.0%, and the 5-year disease-free survival rate was 57.6%. Thirty-nine patients underwent less-than-total parotidectomies, and the remaining 23 patients underwent total parotidectomies. After surgery, 50 patients received adjuvant treatment. During the study, 25 recurrences were documented, including nine local recurrences and 16 distant metastases. The average time period between the end of initial treatment and disease relapse was 17.0 months. A total of 16 patients succumbed to disease progression. Multivariate Cox proportional regression analysis showed that lymphovascular invasion (LVI) was an independent prognostic factor affecting disease recurrence and patient deaths. Among various factors, LVI and lymph node (LN) metastasis showed statistically significant correlations with distant metastasis.

CONCLUSION

Although we achieved favorable therapeutic results using standard treatments in selected patients, T1-2 high-grade parotid cancers generally have poor prognosis. Distant metastases that occur during follow-up are a major factor in treatment failure and LVI and LN metastasis are significantly associated with distant metastasis.

Comprehensive Analysis of Clinicopathologic Factors Predictive of an Unfavorable Prognosis in Patients With Acinic Cell Carcinoma of the Parotid Gland

Objectives.

In subset of patients, acinic cell carcinoma (AcCC) exhibits aggressive features such as recurrence, distant metastasis, and mortality. This study aimed to investigate clinicopathologic factors influencing patients’ prognosis and to identify adverse features predictive of an unfavorable prognosis.

Methods.

Between January 2000 and December 2016, 59 patients with AcCC were enrolled in this study.

Results.

The patients’ 5-year overall survival rate was 93.3%, and their 5-year recurrence-free survival rate was 80.5%. During the study period, recurrence occurred in 10 patients. The mean time to recurrence after surgery was 26 months (range, 5–60 months). During the study period, three patients died from the disease. Univariate analysis showed that sex, surgical extent, extranodal extension, T classification, and TNM stage were significantly associated with disease recurrence. Multivariate analysis showed that, among the clinicopathologic factors included in the analysis, only TNM stage displayed a statistically significant correlation with disease recurrence.

Conclusion.

Surgical treatment alone yielded good results for AcCC, and additional treatment did not affect the recurrence-free survival rate or the overall survival rate, even when the resection margin was less than 1 mm. Other pathologic factors did not show prognostic significance for disease recurrence or death.

Upfront autologous hematopoietic stem cell transplantation for high-risk patients with double-expressor diffuse large B cell lymphoma

Although MYC and BCL2 co-expression in diffuse large B cell lymphoma (DLBCL) is associated with inferior prognosis, it remains uncertain whether upfront autologous hematopoietic stem cell transplantation (ASCT) is beneficial in this lymphoma. This study aimed to investigate whether ASCT consolidation could have a positive role for patients with MYC and BCL2 co-expression (double-expressor lymphoma, DEL). We retrospectively evaluated 67 DLBCL patients who underwent upfront ASCT following rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy. The 5-year overall survival (OS) and progression-free survival (PFS) were 82.3% and 79.2%, respectively. There were 23 (34.3%) patients with DEL and 51 (76.1%) patients with non-germinal center B cell (GCB) subtype. The 5-year OS and PFS of patients with DEL were not different from those with non-DEL (P = 0.429 and P = 0.614, respectively). No survival difference for OS and PFS was also observed between GCB and non-GCB subtypes (P = 0.950 and P = 0.901, respectively). The OS and PFS were comparable for patients with DEL and non-DEL and both GCB and non-GCB subtypes. In conclusion, MYC and BCL2 co-expression did not have a poor prognostic impact among high-risk patients with DLBCL treated with upfront ASCT regardless of molecular classification. This preliminary study suggested that the role of consolidative ASCT is needed to be evaluated in a prospective randomized clinical trial.

Prognostic implications of Fibroblast growth factor receptor 1 (FGFR1) gene amplification and protein overexpression in hypopharyngeal and laryngeal squamous cell carcinoma

Background

The gene encoding fibroblast growth factor receptor 1 (FGFR1) is emerging as a therapeutic and prognostic biomarker in various cancer types, including head and neck squamous cell carcinoma (SCC). Here, we investigated the clinicopathologic implication of FGFR1 gene amplification and protein overexpression in hypopharyngeal and laryngeal SCC.

Methods

Fluorescence in situ hybridization and immunohistochemistry were performed to determine FGFR1 gene amplification and protein overexpression in 209 surgically resected cases.

Results

FGFR1 amplification observed in 8 (8/66, 12.1%; 6 hypopharynx and 2 larynx) patients and high FGFR1 expression in 21 (21/199, 10.6%) patients significantly correlated with lymph node metastasis and advanced pathological stages. FGFR1 amplification was also associated with worse disease-free survival in multivariate analysis (hazard ratio = 4.527, P = 0.032). High FGFR1 expression was more frequently observed, consistent with the worsening of the degree of histologic differentiation.

Conclusions

FGFR1 amplification may serve as an independent prognostic factor for disease-free survival in hypopharyngeal and laryngeal SCC. Aberrant FGFR signaling caused by FGFR1 gene amplification or protein overexpression may play a crucial role in the malignant evolution and progression of hypopharyngeal and laryngeal SCC, and offer novel therapeutic opportunities in patients with hypopharyngeal and laryngeal SCC that usually lack specific therapeutic targets.

Establishment and characterization of patient-derived xenografts as paraclinical models for head and neck cancer

Background

We investigated whether head and neck squamous cell carcinoma (HNSCC) patient-derived xenografts (PDXs) reaffirm patient responses to anti-cancer therapeutics.

Methods

Tumors from HNSCC patients were transplanted into immunodeficient mice and propagated via subsequent implantation. We evaluated established PDXs by histology, genomic profiling, and in vivo anti-cancer efficacy testing to confirm them as the authentic in vivo platform.

Results

From 62 HNSCCs, 15 (24%) PDXs were established. The primary cancer types were tongue (8), oropharynx (3), hypopharynx (1), ethmoid sinus cancer (1), supraglottic cancer (1), and parotid gland (1); six PDXs (40%) were established from biopsy specimens from advanced HNSCC. PDXs mostly retained donor characteristics and remained stable across passages. PIK3CA (H1047R), HRAS (G12D), and TP53 mutations (H193R, I195T, R248W, R273H, E298X) and EGFR, CCND1, MYC, and PIK3CA amplifications were identified. Using the acquisition method, biopsy showed a significantly higher engraftment rate when compared with that of surgical resection (100% [6/6] vs. 16.1% [9/56], P < 0.001). Specimens obtained from metastatic sites showed a significantly higher engraftment rate than did those from primary sites (100% [9/9] vs. 11.3% [6/53], P < 0.001). Three PDX models from HPV-positive tumors were established, as compared to 12 from HPV-negative (15.8% [3/19] and 27.9% [12/43] respectively, P = 0.311), suggesting that HPV positivity tends to show a low engraftment rate. Drug responses in PDX recapitulated the clinical responses of the matching patients with pan-HER inhibitors and pan-PI3K inhibitor.

Conclusions

Genetically and clinically annotated HNSCC PDXs could be useful preclinical tools for evaluating biomarkers, therapeutic targets, and new drug discovery.

Characterization of novel genetic alterations in salivary gland secretory carcinoma

Secretory carcinoma is a salivary gland tumor with a characteristic chromosomal translocation that results in an ETV6-NTRK3 fusion gene. Secretory carcinoma shows relatively frequent rates of lymph-node metastasis and tumor recurrence and has a characteristic histology. Except for the ETV6 translocation, genomic alterations in secretory carcinoma have not been reported. In the present study, we characterized the novel recurrent genetic mutations of secretory carcinoma. On the basis of histology, immunohistochemistry, and ETV6 gene break-apart fluorescence in situ hybridization assays, 22 tumors were classified as secretory carcinomas (19 ETV6 translocation-positive and 3 ETV6 translocation-negative secretory carcinomas) and their clinicopathologic characteristics were reviewed. Targeted deep sequencing analyses were performed on 20 secretory carcinomas (17 ETV6 translocation-positive and 3 ETV6 translocation-negative secretory carcinomas) to investigate their genetic alterations. The A16V (C→T) mutation in PRSS1, which encodes a cationic trypsinogen and has a mutation associated with hereditary pancreatitis and pancreatic adenocarcinoma, was observed in 40% (8/20) (7/17 of ETV6 translocation-positive and 1/3 of ETV6 translocation-negative secretory carcinomas). Pathogenic variants of MLH1, MUTYH, and STK11 were also identified. Variants of uncertain significance included mutations in KMT5A. These novel characteristic genetic alterations may advance current understandings of secretory carcinoma tumorigenesis and progression, leading to improved diagnoses and treatment strategies.

Molecular subtypes of oropharyngeal cancer show distinct immune microenvironment related with immune checkpoint blockade response

Background

Oropharyngeal cancer (OPC) exhibits diverse immunological properties; however, their implications for immunotherapy are unknown.

Methods

We analysed 37 surgically resected and nine recurrent or metastatic anti-programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1)-treated OPC tumours. OPCs were classified into immune-rich (IR), mesenchymal (MS) and xenobiotic (XB) subtypes based on RNA-sequencing data.

Results

All IR type tumours were human papillomavirus (HPV) positive, most XB types were HPV negative, and MS types showed mixed HPV status. The IR type showed an enriched T cell exhaustion signature with PD-1⁺ CD8⁺ T cells and type I macrophages infiltrating the tumour nest on multiplex immunohistochemistry. The MS type showed an exclusion of CD8⁺ T cells from the tumour nest and high MS and tumour growth factor-β signatures. The XB type showed scant CD8⁺ T cell infiltration and focal CD73 expression. The IR type was associated with a favourable response signature during anti-PD-1/PD-L1 therapy and showed a high APOBEC mutation signature, whereas the MS and XB types showed resistance signature upregulation. Among anti-PD-1/PD-L1-treated OPC patients, the IR type showed a favourable clinical response (3/4 patients), whereas the XB type showed early progression (3/3 patients).

Conclusion

Our analysis classified OPCs into three subtypes with distinct immune microenvironments that are potentially related to the response to anti-PD-1/PD-L1 therapy.

Consequences of Metabolic Disruption in Alzheimer's Disease Pathology

Alzheimer's disease (AD) is an irreversible, progressive disease that slowly destroys cognitive function, such as thinking, remembering, and reasoning, to a level that one cannot carry out a daily living. As people live longer, the risk of developing AD has increased to 1 in 10 among people who are older than 65 and to almost 1 in 2 among those who are older than 85 according to a 2019 Alzheimer's Association report. As a most common cause of dementia, AD accounts for 60-80% of all dementia cases. AD is characterized by amyloid plaques and neurofibrillary tangles, composed of extracellular aggregates of amyloid-β peptides and intracellular aggregates of hyperphosphorylated tau, respectively. Besides plaques and tangles, AD pathology includes synaptic dysfunction including loss of synapses, inflammation, brain atrophy, and brain hypometabolism, all of which contribute to progressive cognitive decline. Recent genetic studies of sporadic cases of AD have identified a score of risk factors, as reported by Hollingworth et al. (Nat Genet 43:429-435, 2001) and Lambert et al. (Nat Genet 45:1452-1458, 2013). Of all these genes, apolipoprotein E4 (APOE4) still presents the biggest risk factor for sporadic cases of AD, as stated in Saunders et al. (Neurology 43:1467-1472, 1993): depending on whether you have 1 or 2 copies of APOE4 allele, the risk increases from 3- to 12-fold, respectively, in line with Genin et al. (Mol Psychiatry 16:903-907, 2011). Besides these genetic risk factors, having type 2 diabetes (T2D), a chronic metabolic disease, is known to increase the AD risk by at least 2-fold when these individuals age, conforming to Sims-Robinson et al. (Nat Rev Neurol 6:551-559, 2010). Diabetes is reaching a pandemic scale with over 422 million people diagnosed worldwide in 2014 according to World Health Organization. Although what proportion of these diabetic patients develop AD is not known, even if 10% of diabetic patients develop AD later in their life, it would double the number of AD patients in the world. Better understanding between T2D and AD is of paramount of importance for the future. The goal of this review is to examine our current understanding on metabolic dysfunction in AD, so that a potential target can be identified in the near future.

Clinicopathological and Preclinical Findings of NUT Carcinoma: A Multicenter Study

BACKGROUND

NUT carcinoma is a rare aggressive disease caused by BRD4/3-NUT fusion, and C-MYC upregulation plays a key role in the pathogenesis. Here, we report on the clinicopathological characteristics of Korean patients with NUT carcinoma and the in vitro efficacy of MYC-targeting agents against patient-derived NUT carcinoma cell lines.

MATERIALS AND METHODS

Thirteen patients with NUT carcinoma were evaluated for p53, C-MYC, epidermal growth factor receptor (EGFR), HER2, and programmed cell death ligand 1 (PD-L1) by immunohistochemistry. The half maximal inhibitory concentration (IC₅₀) values of NUT carcinoma cell lines (SNU-2972-1, SNU-3178S, HCC2429, and Ty-82) were determined using MYC-targeting agents, including bromodomain and extraterminal (BET) inhibitors (I-BET, OTX-015, AZD5153) and histone deacetylase (HDAC) inhibitors (vorinostat, romidepsin, panobinostat, CUDC-907).

RESULTS

Primary tumor sites included head and neck (n = 9) and lung (n = 4). The patient age ranged from 8 to 73 years with the male/female ratio of 1.2:1. Nine patients died at 3-23.6 months (median, 10.6) after diagnosis. Eight patients had been misdiagnosed initially with other diseases. One patient with metastatic NUT carcinoma who received mass excision plus metastasectomy followed by chemoradiotherapy was a long-term survivor (>27 months). Although expressions of C-MYC (8/12, 73%) and p53 (12/12, 100%) were commonly observed, EGFR, HER2, and PD-L1 expressions were observed in 2 of 7 (29%), 2 of 8 (25%), and 1 of 12 (8.3%) patients, respectively. BET and HDAC inhibitors showed variable but limited in vitro efficacy. However, a dual HDAC/PI3K inhibitor, CUDC-907, was most potent against NUT carcinoma cells, with an IC₅₀ of 5.5-9.0 pmol/L. Consistent with these findings, kinome short interfering RNA screening showed a positive hit for PI3KCA in NUT carcinoma cells. Panobinostat (IC₅₀, 0.4-1.3 nmol/L) and a bivalent BET inhibitor, AZD5153 (IC₅₀, 3.7-8.2 nmol/L), also showed remarkable efficacies.

CONCLUSION

East Asian patients with NUT carcinoma showed dismal survival outcomes like Western patients, and CUDC-907 might be promising in NUT carcinoma treatment.

IMPLICATIONS FOR PRACTICE

NUT carcinoma (NC) is a disease caused by BRD-NUT fusion leading to C-MYC upregulation. NC is often misdiagnosed and very aggressive, requiring development of effective therapeutic strategy. This article presents the clinicopathological features of the largest series of NCs in East Asians and preclinical sensitivities to MYC-targeting agents in NC cell lines. Patients with NC had grave outcomes and poor response to treatment. Among MYC-targeting agents, including BET and HDAC inhibitors, CUDC-907 (a dual PI3K/HDAC inhibitor) was most effective against NC cells, followed by panobinostat (an HDAC inhibitor) and AZD5153 (a bivalent BET inhibitor). CUDC-907 might be promising in NC treatment.

Expression of EpCAM in adenoid cystic carcinoma

The mutational landscape of adenoid cystic carcinoma (ACC) is currently being revealed, but further studies are needed to identify biomarkers as therapeutic targets or prognostic factors of ACC. In this study, we investigated the expression of epithelial cell adhesion molecule (EpCAM) in ACCs. We retrospectively collected 83 cases of surgically resected ACCs. Using tissue microarray, we conducted immunohistochemical staining using the anti-EpCAM antibody. EpCAM expression was analysed by intensity score and the total immunostaining score. The positivity was 97.6% (81/83 cases), regardless of the intensity score. A higher histological grade (p = 0.006) and specific tumour location (non-salivary gland origin, p = 0.02) showed a correlation with higher EpCAM intensity. Higher EpCAM expression by total immunostaining score was associated with histological grade (p = 0.004), distant metastasis (p = 0.004) and poorer prognosis (overall survival p = 0.015 and progression-free survival p = 0.033). We suggest EpCAM as a candidate prognostic marker and a putative therapeutic target in ACC. Also, ACCs arising from salivary gland and non-salivary gland sites, respectively, might display different pathophysiologies in which EpCAM could play a role.

Investigating Trk Protein Expression between Oropharyngeal and Non-oropharyngeal Squamous Cell Carcinoma: Clinical Implications and Possible Roles of Human Papillomavirus Infection

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.

Abstract 3990: Clinicopathologic findings and in vitro efficacy of MYC-targeting agentsin NUT midline carcinoma

Purpose: NUT midline carcinoma (NMC) is an aggressive and poorly differentiated carcinoma defined by chromosomal rearrangements of NUT gene, which is fused to the BET family genes (BRD3/4). Although NMC is extremely rare and mostly reported in a Western population, clinico-pathologic findings of Asian NMC patients are not well studied. Here, we performed the clinicopathologic analysis of Korean NMC cases and in vitro efficacy of MYC-targeting agents against patient-derived NMC cell lines.

Experimental Design: A total of 12 NMC patients (3 thoracic and 9 head and neck origins) were collected in Korean multi-centers by immunohistochemistry (IHC) and fluorescence in situ hybridization for NUT. IHC staining was performed for c-MYC, p53, EGFR, HER2, and PD-L1. NMC cell lines (SNU-2972-1, SNU-3178S, HCC2429, and Ty-82) were exposed to MYC-targeting agents including BET (I-BET, OTX-015, and AZD5153) and HDAC (vorinostat, romidepsin, panobinostat, and CUDC-907) inhibitors. Cell viability assays were performed and IC50 values were determined.

Results: Primary sites of tumor included sinonasal area (n=7), salivary gland (n=2), and thorax/lung (n=3). The median age was 47.5 years (range, 8-73 years) with equal male-to-female ratio. NUT immunostaining showed diffuse positivity in all except for one who had focal NUT positivity. C-MYC and p53 were expressed in all evaluated cases. PD-L1 expression was observed only in a patient (8.3%). Seven of 12 patients died at 3-24 months (median, 9 months) after diagnosis. Long-term survivor was observed in one patient with stage IV NMC who received mass excision plus metastasectomy followed by 6 cycles of docetaxel plus cisplatin and radiotherapy (survival &gt; 27 months). Although BET and HDAC inhibitors showed limited in vitro efficacies against NMC cells, a dual HDAC/PI3K inhibitor, CDUC-907 exhibited the most potent efficacy with the IC50 of 6.2 to 9 pmol/L.

Conclusions: Korean NMC patients pursued grave prognosis like Western patients except one long-term survivor who received tri-modality treatments. Dual HDAC/PI3K inhibitor might be promising in NMC treatment.

Citation Format: Soyeon Kim, Minsun Jung, Heae Surng Park, Sun Och Yoon, Soon Won Hong, Weon-Seo Park, Bhumsuk Keam, Hyun Jik Kim, Dong-Wan Kim, Young Tae Kim, Dae Seong Heo, Tae Min Kim, Yoon Kyung Jeon. Clinicopathologic findings and in vitro efficacy of MYC-targeting agentsin NUT midline carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3990.

The implications of TrkA and MET aberrations in de novo salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive carcinoma with poor prognosis. Although anti-HER2 therapy is a potential treatment option for HER2-positive SDC, other potential therapeutic targets are not known, in particular for HER2-negative cases. In this study, the recently identified receptors tyrosine kinases MET and tropomyosin-receptor kinase (Trk) were investigated as potential therapeutic targets. A total of 28 consecutive, surgically resected, de novo SDC cases were selected after evaluating histology and immunohistochemical expression of androgen receptor. Immunohistochemical expression of c-erb2, TrkA, TrkB, TrkC, and c-MET was analyzed, and the genetic status of the HER2 and MET genes was investigated through dual-color silver in situ hybridization. High expression of c-MET or Trk was defined as that above the median value. Among the 28 SDC cases, 64.3% (18/28) were HER2-positive. c-MET expression varied, with a median H-score of 65 (range, 0 to 200). Copy number gain and amplification of MET were noted in 57.1% (16/28) and 10.7% (3/28) of cases, respectively. TrkA was variably expressed, with a median H-score of 100 (range, 0 to250). High TrkA expression was significantly related to an inferior overall survival rate in HER2-negative SDC. High expression of TrkA and c-MET and MET copy number gain/amplification were frequent events in SDC, and high expression of TrkA revealed the tendency to be related to poor prognosis in HER2-negative SDC. TrkA and MET may be possible therapeutic targets in SDC, especially in HER2-negative SDC.

Association of the long non-coding RNA MALAT1 with the polycomb repressive complex pathway in T and NK cell lymphoma

Recently, various long non-coding RNAs (lncRNAs) have been reported to have significant therapeutic or prognostic value. However, the expression of lncRNAs has not been investigated in T and NK cell lymphoma. Thus, we evaluated the biological and prognostic role of lncRNAs related to the polycomb repressive complex (PRC) and PRC markers in tissue samples and cell lines of T and NK cell lymphoma. Among the tested lncRNAs, MALAT1 was most highly expressed in clinical samples and cell lines. High expression of MALAT1 as well as BMI1 was related to poor prognosis in patients with mature T cell lymphoma. In the tissue samples, BMI1 expression showed a positive correlation with EZH2, SUZ12, H3K27me3, and MALAT1. Multiple linear regression analysis showed that BMI1 expression was independently associated with H3K27me3. Direct binding of MALAT1 to the PRC2 components (EZH2 and SUZ12) was observed in a T cell lymphoma cell line; however, no direct binding of MALAT1 with H3K27me3 and BMI1 (a PRC1 component) was observed.

In T and NK cell lymphomas, MALAT1 was related to poor prognosis. MALAT1 directly binds to EZH2 and SUZ12, and BMI1 activation may be induced possibly through H3K27me3.

Acquired resistance to BRAF inhibition induces epithelial-to-mesenchymal transition in BRAF (V600E) mutant thyroid cancer by c-Met-mediated AKT activation

Previously, the authors have identified that c-Met mediates reactivation of the PI3K/AKT pathway following BRAF inhibitor treatment in BRAF (V600E) mutant anaplastic thyroid cancer, thereby contributing to the acquired drug resistance. Therefore dual inhibition of BRAF and c-Met led to sustained treatment response, thereby maximizing the specific anti-tumor effect of targeted therapy. The present study goes one step further and aims to investigate the effect of acquired resistance of BRAF inhibitor on epithelial-to-mesenchymal transition (EMT) in BRAF mutant thyroid cancer cells and the effect of dual inhibition from combinatorial therapy. Two thyroid cancer cell lines, 8505C and BCPAP were selected and treated with BRAF inhibitor, PLX4032 and its effect on EMT were examined and compared. Further investigation was carried out in orthotopic xenograft mouse models. Unlike BCPAP cells, the BRAF inhibitor resistant 8505C cells showed increased expressions of EMT related markers such as vimentin, β-catenin, and CD44. The combinatorial treatment of PLX4032 and PHA665752, a c-Met inhibitor reversed EMT. Similar results were confirmed in vivo. c-Met-mediated reactivation of the PI3K/AKT pathway contributes to the drug resistance to PLX4032 in BRAF (V600E) mutant anaplastic thyroid cancer cells and further promotes tumor cell migration and invasion by upregulated EMT mechanism. Dual inhibition of BRAF and c-Met leads to reversal of EMT, suggesting a maximal therapeutic response.

The long noncoding RNA HOXA11 antisense induces tumor progression and stemness maintenance in cervical cancer

Recent research has focused on the impact of long noncoding RNA (lncRNA) in cervical carcinogenesis. However, whether HOXA11 antisense (HOXA11-AS) is involved in cervical cancer remains to be elucidated. In the present study, we examined HOXA11-AS expression levels in cervical cancer patients and determined the relationships between HOXA11-AS expression and clinicopathological factors. We also investigated the bio-functional consequences of HOXA11-AS overexpression both in vitro and in vivo. HOXA11-AS expression was significantly greater in tissues from patients with cervical cancer than in control patients (P<0.001). Multivariate analysis showed that high HOXA11-AS was an independent prognosticator of overall survival (Hazard ratio=2.450, P=0.032). HOXA11-AS overexpression enhanced cell proliferation, migration, and tumor invasion in vitro, whereas HOXA11-AS knockdown inhibited these biologic aggressive features. These adverse changes were accompanied by characteristics of epithelial-mesenchymal transition (EMT). In vivo xenograft experiments using the siHOXA11-AS-transfected HeLa cells revealed that HOXA11-AS strongly induced tumor growth. Furthermore, we found that HOXA11-AS knockdown decreased cancer stemness and triggered the EMT program. In conclusion, HOXA11-AS overexpression correlated with poor survival in patients with cervical cancer. Thus, HOXA11-AS may be a pivotal target for exploring novel cervical cancer therapeutics.

Diagnostic Approaches for Salivary Gland Tumors with Secretory and Microcystic Features

Secretory carcinoma (SC) of the salivary gland is a new entity that shares the unique morphologic features and cytogenetic characteristics of the ETV6-NTRK3 fusion gene with its breast counterpart. Before identification of SC of the salivary gland, it was most frequently diagnosed as acinic cell carcinoma (AciCC). We retrospectively reviewed our own database of salivary gland tumors harboring microcystic and papillary architecture and/or secretory features that were originally diagnosed as AciCC. We selected nine cases of AciCC showing diffuse S-100 expression on immunohistochemistry (IHC). A recently diagnosed case of SC was included in the study as a reference sample. We performed IHC of S-100 and mammaglobin and ETV6 gene fluorescence in situ hybridization (FISH) in all cases. Seven cases were positive for both S-100 and mammaglobin, while five of the seven (71.4%) demonstrated ETV6 gene translocation by FISH. In the cases which did not co-express either S-100 or mammaglobin on IHC, ETV6 gene rearrangement was not shown on FISH. In conclusion, if a salivary gland tumor has morphologic features of SC with co-expression of S-100 and mammaglobin, ETV6 FISH can be performed to confirm the diagnosis of SC of the salivary gland.

Molecular Testing of Lymphoproliferative Disorders: Current Status and Perspectives

Molecular pathologic testing plays an important role for the diagnosis, prognostication and decision of treatment strategy in lymphoproliferative disease. Here, we briefly review the molecular tests currently used for lymphoproliferative disease and those which will be implicated in clinical practice in the near future. Specifically, this guideline addresses the clonality test for B- and T-cell proliferative lesions, molecular cytogenetic tests for malignant lymphoma, determination of cell-of-origin in diffuse large B-cell lymphoma, and molecular genetic alterations incorporated in the 2016 revision of the World Health Organization classification of lymphoid neoplasms. Finally, a new perspective on the next-generation sequencing for diagnostic, prognostic, and therapeutic purpose in malignant lymphoma will be summarized.

Implications of NOVA1 suppression within the microenvironment of gastric cancer: association with immune cell dysregulation

BACKGROUND

The neuronal splicing factor neuro-oncological ventral antigen 1 (NOVA1) is enriched in normal fibroblasts. Stromal spindle cells such as fibroblasts are major components of tissue inflammation and tertiary lymphoid structures within the microenvironment that contribute to the survival and growth of cancer cells. In the present study, we investigated changes of NOVA1 expression in tertiary lymphoid structures in early and advanced gastric cancer microenvironments in terms of tumor progression and immune regulation.

METHODS

Using immunohistochemistry, we analyzed NOVA1 expression in tumor cells, T cells, and stromal spindle cells as well as infiltrating densities of CD3⁺ T cells, forkhead box P3 positive (FOXP3⁺) regulatory T cells, CD68⁺ macrophages, CD163⁺ M2 macrophages, and myeloperoxidase-positive neutrophils in 396 surgically resected gastric cancer tissues.

RESULTS

Suppressed NOVA1 expression in tumor cells, T cells, and stromal spindle cells was closely related to decreased infiltration of FOXP3⁺ regulatory T cells, increased infiltration of CD68⁺ macrophages and CD163⁺ M2 macrophages, more advanced tumor stage, and inferior overall survival rate. In addition, low infiltration of CD3⁺ T cells and FOXP3⁺ regulatory T cells and high infiltration of CD68⁺ macrophages were associated with inferior overall survival. Specifically, weak NOVA1 expression in tumor cells was independently related to more advanced tumor stage and inferior overall survival.

CONCLUSIONS

NOVA1 suppression was frequently noted in the gastric cancer microenvironment, and attenuated NOVA1 expression in tumor cells was associated with tumor progression and poor prognosis. This finding seems to be related to immune dysfunction through changes in the immune cell composition of T cells and macrophages.

Implications of infiltrating immune cells within bone marrow of patients with diffuse large B-cell lymphoma

The implications of infiltrating immune cells, especially T cells and macrophages, in the bone marrow (BM) microenvironment of patients with diffuse large B-cell lymphoma (DLBCL) have rarely been studied. We aimed to investigate the significance of infiltrating immune cells in the BM microenvironment as a prognostic factor for DLBCL patients. Using the initial pretreatment BM biopsy obtained from 198 DLBCL patients, we semiquantitatively evaluated CD3+ T cells, CD8+ T cells, and CD163+ macrophages that infiltrate into the paratrabecular and interstitial areas of BM by immunohistochemistry and analyzed their clinicopathological and prognostic implications. Levels of infiltrating CD3+ T cells, CD8+ T cells, and CD163+ macrophages were significantly higher in BM with DLBCL involvement (BMI-positive group) than in that without DLBCL involvement (BMI-negative group). Infiltration of CD8+ T cells significantly increased in cases with advanced Ann Arbor stage, elevated lactate dehydrogenase level, extranodal site involvement ≥2 sites, higher Eastern Cooperative Oncology Group performance status, and higher International Prognostic Index (IPI) risk. High levels of CD3+ T cells were significantly associated with age ≤60, and high levels of CD163+ macrophages were associated with advanced Ann Arbor stage and higher IPI risk. High infiltration of CD8+ T cells was significantly related to inferior overall and recurrence-free survival rate, even in the BMI-negative group. High infiltration of CD8+ T cells within the pretreatment BM was related to poor prognosis, and might be a useful prognostic factor of DLBCL patients. Therefore, evaluation of CD8+ T cells is helpful for predicting prognosis in initial pretreatment BM biopsy of DLBCL patients.

Alteration status and prognostic value of MET in head and neck squamous cell carcinoma

The MET pathway plays a key role in various cancers, and its inhibition represents a potential treatment target. However, appropriate biomarkers are needed to facilitate the selection of patients who would benefit from MET inhibiting therapy. We herein conducted a robust confirmatory evaluation of the MET copy number alteration status and prognostic significance of c-Met expression in a large series of patients (n = 396) who underwent standard surgical resection and adjuvant chemoradiotherapy for head and neck squamous cell carcinoma (HNSCC). Surgically resected HNSCC samples were subjected to immunohistochemical and H-score analysis of c-Met expression and silver in situ hybridization analysis of MET amplification and copy number gains. c-Met expression varied, with mean and median H-scores (scale: 0-300 scale) of 61.2 and 60.0, respectively. The lowest and highest expression levels were observed in SCC of the larynx and oral cavity, respectively. MET copy number gains were observed in 16.9% of cases (67/339) and were associated with c-Met protein expression. High c-Met expression, determined according to MET gain status, was associated with an inferior overall survival rate, especially among completely resected cases. In conclusion, our robust analysis revealed that c-Met expression in HNSCCs varied according to anatomical site, correlated with MET copy number gains, and was associated with poor prognosis. This c-Met expression analysis method, which is based on the MET gain status, appears to appropriately predict high-risk HNSCC patients in the context of anti-MET therapeutic decisions.

Long Non-coding RNA HOTAIR Expression in Diffuse Large B-Cell Lymphoma: In Relation to Polycomb Repressive Complex Pathway Proteins and H3K27 Trimethylation

BACKGROUND

A long non-coding RNA hox transcript antisense intergenic RNA (HOTAIR) is involved in epigenetic regulation through chromatin remodeling by recruiting polycomb repressive complex 2 (PRC2) proteins (EZH2, SUZ12, and EED) that induce histone H3 trimethylation at lysine 27 (H3K27me3). Deregulation of c-MYC and interaction between c-MYC and EZH2 are well known in lymphomagenesis; however, little is known about the expression status of HOTAIR in diffuse large B-cell lymphomas (DLBCLs).

METHODS

The expression status of PRC2 (EZH2, SUZ12, and EED), H3K27me3, c-MYC, and BCL2 was analyzed using immunohistochemistry (n = 231), and HOTAIR was investigated by a quantification real-time polymerase chain reaction method (n = 164) in DLBCLs.

RESULTS

The present study confirmed the positive correlation among PRC2 proteins, H3K27me3, and c-MYC in DLBCLs. Expression level of HOTAIR was also positively correlated to EZH2 (p < .05, respectively). Between c-MYC and HOTAIR, and between c- MYC/BCL2 co-expression and HOTAIR, however, negative correlation was observed in DLBCLs (p < .05, respectively). High level of H3K27me3 was determined as an independent prognostic marker in poor overall survival (hazard ratio, 2.0; p = .023) of DLBCL patients. High expression of HOTAIR, however, was associated with favorable overall survival (p = .004) in the univariate analysis, but the impact was not significant in the multivariate analysis. The favorable outcome of DLBCL with HOTAIR high expression levels may be related to the negative correlation with c- MYC expression or c-MYC/BCL2 co-expression.

CONCLUSIONS

HOTAIR expression could be one of possible mechanisms for inducing H3K27me3 via EZH2-related PRC2 activation, and induced H3K27me3 may be strongly related to aggressive DLBCLs which show poor patient outcome.

The prognostic significance of monoclonal immunoglobulin gene rearrangement in conjunction with histologic B-cell aggregates in the bone marrow of patients with diffuse large B-cell lymphoma

Bone marrow involvement (BMI) is a well‐known poor prognostic factor in patients with diffuse large B‐cell lymphoma (DLBCL). This study robustly investigated the significance of monoclonal immunoglobulin gene rearrangement combined with histologic B‐cell aggregates in bone marrow (BM) in the detection of a poor prognostic group. Pretreatment BM samples of 394 DLBCL patients were analyzed via the immunoglobulin gene rearrangement study and the microscopic examination. Monoclonal immunoglobulin gene rearrangement was detected in 25.4% of cases. Histologic B‐cell aggregates with the features of large B‐cell lymphoma aggregates, small cell B‐cell lymphoma aggregates, or B‐cell aggregates of unknown biological potential were observed in 12% of cases (6.9%, 1.3%, and 3.8%, respectively). Histologic B‐cell aggregates were more associated with monoclonality than polyclonality. Cases with both monoclonality and histologic B‐cell aggregates demonstrated close association with poor prognostic factors such as a higher International Prognostic Index score and showed an inferior overall survival rate when compared to cases with only monoclonality or only histologic B‐cell aggregates. From the findings, a combination of monoclonality and histologic B‐cell aggregates within the bone marrow was highly associated with poor prognosis and could be used to determine high‐risk DLBLC patients with greater sensitivity and specificity than conventional microscopic examination or immunoglobulin gene rearrangement study alone.

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.

Overexpression of Endoplasmic Reticulum Oxidoreductin 1-α (ERO1L) Is Associated with Poor Prognosis of Gastric Cancer

Purpose

Gastric cancer is the second leading cause of cancer-related death worldwide. Although surgery is the standard curative treatment for gastric cancer, relapse occurs in a large number of patients, except in the case of early diagnosed gastric cancer. Following previous studies that identified endoplasmic reticulum oxidoreductin 1-α (ERO1L) as a potential marker for gastric cancer, we investigated the functional role of ERO1L in gastric cancer.

Materials and Methods

For validation of microarray data, the mRNA expression level of ERO1L was measured by quantitative real-time reverse transcription polymerase chain reaction in 56 independent stage III gastric cancer patients. Immunohistochemical staining was performed to examine the protein expression level of ERO1L in 231 gastric cancer patients. Correlation between gene expression and cancer prognosis was evaluated.

Results

Patients with high ERO1L expression had poorer survival than those with low expression (p < 0.01). Functional assays demonstrated that ERO1L knockdown inhibited cell proliferation, migration, invasion, and chemoresistance. In addition, involvement of inactivation of Akt and JNK signaling in molecular mechanisms of ERO1L inhibition was demonstrated.

Conclusion

High expression of ERO1L is associated with poor prognosis of patients with gastric cancer. These results indicate that ERO1L expression may be a clinically promising therapeutic target for prevention of gastric cancer.

NOVA1 inhibition by miR-146b-5p in the remnant tissue microenvironment defines occult residual disease after gastric cancer removal

Occult residual disease in remnant tissues could be the cause of tumor relapse. To identify signal molecules and target cells that may be indicative of occult residual disease within a remnant microenvironment, proximal resection margin tissues of gastric cancers were used, as these correspond to the nearest remnant tissues after gastrectomy. Increased miR-146b-5p in the remnant microenvironment was determined to be a strong risk factor for tumor relapse and poor survival rate. NOVA1, a target gene of miR-146b-5p, was decreased in remnant tissues of patients with a poor prognosis. NOVA1 was enriched in stromal spindle cells such as fibroblasts within normal tissues. In non-neoplastic inflammation, such as gastritis, NOVA1 was highly enriched in T lymphocytes and stromal spindle cells, while expression of this protein was frequently decreased in those types of cells within gastric cancer tissues. Particularly, decreased NOVA1 in T cells within the gastric cancer tissues was correlated with decreased FOXP3-positive regulatory T cells and was associated with poor patient prognosis. In vitro analysis showed that the NOVA1 gene was inhibited by miR-146b-5p. In immune cells as well as stromal spindle cells, decreased NOVA1, possibly inhibited by miR-146b-5p, is a candidate biomarker predicting poor prognosis of gastric cancer patients and is also a biomarker of occult residual disease in remnant tissues after gastric cancer removal.

Activation of the polycomb repressive complex pathway in the bone marrow resident cells of diffuse large B-cell lymphoma patients

The present study investigated the activation of polycomb repressive complex 2 (PRC2) pathway proteins in the resident cells within the bone marrow hematopoietic microenvironment of diffuse large B-cell lymphoma (DLBCL) patients. PRC2 proteins (enhancer of zeste homolog 2, suppressor of zeste 12 homolog, and embryonic ectoderm development), histone methylation mark (H3K27me3), and c-MYC activation were evaluated in pretreatment bone marrow from 208 DLBLC patients. Positive expression of the PRC2, H3K27me3, and c-MYC in the bone marrow resident cells was more frequent in cases with bone marrow involvement of tumor. The expression among PRC2, H3K27me3 mark, and c-MYC was closely correlated. Positive PRC2 expression in bone marrow resident cells was significantly associated with inferior progression-free survival (PFS) and overall survival (OS) and determined to be an independent prognostic factor of inferior PFS and OS. In conclusion, the PRC pathway was frequently activated in bone marrow resident cells of DLBCL patients, and PRC activation was tumor-related and associated with poor clinical outcomes.