Prognostic role of transcription factor ARID1A in patients with endometrial cancer of no specific molecular profile (NSMP) subtype

OBJECTIVE

As more than 50% of newly diagnosed endometrial cancers remain classified as 'no specific molecular subtype' (NSMP) due to a lack of established biomarkers to further improve molecular subtyping, this study aims to evaluate the prognostic value of ARID1A in endometrial cancers of NSMP subtype.

METHODS

Prospectively collected molecular profiling data of all consecutive patients with endometrial cancer who underwent primary surgery at our department between August 2017 and June 2022 and for whom both molecular profiling and clinical follow-up data were available were retrospectively evaluated. Tumor specimens were evaluated by combined mismatch repair protein immunohistochemistry and targeted next-generation hotspot sequencing. ARID1A mutational status, as defined by full-length gene sequencing, was matched with risk of recurrence, progression-free and disease-specific survival within the NSMP cohort.

RESULTS

A total of 127 patients with endometrial cancer were included. Among 72 patients with tumors of NSMP subtype (56.7%), ARID1A mutations were identified in 24 cases (33.3%). ARID1A mutations were significantly associated with a higher risk of recurrence (37.5% vs 12.5%, OR 4.20, 95% CI 1.28 to 13.80, p=0.018) and impaired progression-free survival (HR 3.96, 95% CI 1.41 to 11.15, p=0.009), but not with disease-specific survival. The results for both risk of recurrence (OR 3.70, 95% CI 1.04 to 13.13, p=0.043) and progression-free survival (HR 3.19, 95% CI 1.10 to 9.25, p=0.033) were confirmed in multivariable analysis compared with advanced tumor stage International Federation of Gynecology and Obstetrics (2009) (FIGO ≥III) and impaired Eastern Clinical Oncology Group performance status (ECOG ≥1).

CONCLUSION

ARID1A appears to identify patients with endometrial cancer of NSMP subtypes with a higher risk of recurrence and could be used as a future prognostic biomarker. After clinical validation, ARID1A assessment could help to further sub-classify selected endometrial cancers and improve personalized treatment strategies.

Biomarkers for checkpoint inhibitor therapy in mucinous epithelial ovarian cancer

OBJECTIVE

The prognosis of patients with advanced stage mucinous epithelial ovarian cancer remains poor due to a modest response to platinum-based chemotherapy and the absence of therapeutic alternatives. As targeted approaches may help to overcome these limitations, the present study evaluates biomarkers indicative of potential immune-checkpoint inhibitor therapy response.

METHODS

All patients who underwent primary cytoreductive surgery from January 2001 to December 2020 and for whom formalin-fixed paraffin-embedded tissue samples were available were included (n=35; 12 International Federation of Gynecology and Obstetrics (FIGO) stage ≥IIb). To define sub-groups potentially suitable for checkpoint inhibition, expression of programmed death-ligand 1 (PD-L1), tumor-infiltrating lymphocytes (CD3+, CD8+, CD20+, CD45+, CD68+, FoxP3+), and AT-rich interactive domain-containing protein 1A (ARID1A) immunostaining were evaluated in whole tissue sections and compared with clinicopathologic parameters and next-generation sequencing results, where available (n=11). Survival analyses were performed to assess whether identified sub-groups were associated with specific clinical outcomes.

RESULTS

In total, 34.3% (n=12/35) of tumors were PD-L1 positive. PD-L1 expression was associated with infiltrative histotype (p=0.027) and correlated with higher CD8+ (r=0.577, p<0.001) and CD45+ (r=0.424, p=0.011), but reduced ARID1A expression (r=-4.39, p=0.008). CD8+ expression was associated with longer progression-free survival (hazard ratio (HR) 0.85 (95% CI 0.72 to 0.99), p=0.047) and disease-specific survival (HR 0.85 (95% CI 0.73 to 1.00), p=0.044) in the sub-group with FIGO stage ≥IIb. Three (8.6%) samples demonstrated high PD-L1 expression at a combined positive score of >10, which was associated with increased CD8+ expression (p=0.010) and loss of ARID1A expression (p=0.034). Next-generation sequencing, which was available for all samples with a combined positive score of >10, showed KRAS mutations, BRCA wild-type status, and mismatch repair proficiency in all cases, but did not reveal genetic alterations potentially associated with a pro-immunogenic tumor environment.

CONCLUSIONS

A sub-group of mucinous ovarian cancers appear to demonstrate a pro-immunogenic tumor environment with high PD-L1 expression, decreased ARID1A expression, and characteristic tumor-infiltrating lymphocyte infiltration patterns. Further clinical validation of anti-PD-L1/PD-1 targeting in selected mucinous ovarian cancers appears promising.

Comparative analysis of prognostic histopathologic parameters in subtypes of epithelioid pleural mesothelioma

AIMS

Malignant pleural mesothelioma (MPM) is a rare malignancy with a dismal prognosis. While the epithelioid type is associated with a more favourable outcome, additional factors are needed to further stratify prognosis and to identify patients who can benefit from multimodal treatment. As epithelioid MPM shows remarkable morphological variability, the prognostic role of the five defined morphologies, the impact of the nuclear grading system and the mitosis-necrosis score were investigated in this study.

METHODS AND RESULTS

Tumour specimens of 192 patients with epithelioid MPM from five European centres were histologically subtyped. Nuclear grading and mitosis-necrosis score were determined and correlated with clinicopathological parameters and overall survival (OS). Digital slides of 55 independent cases from The Cancer Genome Atlas (TCGA) database were evaluated for external validation. Histological subtypes were collapsed into three groups based on their overlapping survival curves. The tubulopapillary/microcystic group had a significantly longer OS than the solid/trabecular group (732 days versus 397 days, P = 0.0013). Pleomorphic tumours had the shortest OS (173 days). The solid/trabecular variants showed a significant association with high nuclear grade and mitosis-necrosis score. The mitosis-necrosis score was a robust and independent prognostic factor in our patient cohort. The prognostic significance of all three parameters was externally validated in the TCGA cohort. Patients with tubulopapillary or microcystic tumours showed a greater improvement in OS after receiving multimodal therapy than those with solid or trabecular tumours.

CONCLUSIONS

Histological subtypes of epithelioid MPM have a prognostic impact, and might help to select patients for intensive multimodal treatment approaches.

DNA methylation profiling in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors

e18527

Background: Biomarkers for response prediction to immune checkpoint inhibitors in head and neck squamous cell carcinoma (HNSCC) patients are needed for a personalized therapy regimen. Therefore, we investigated the predictive potential of inflammatory biomarkers and DNA methylation. Methods: We profiled the methylation status of 850.000 CpG sites in formalin-fixed, paraffin-embedded primary HNSCC samples collected before ICI therapy start using Infinium Methylation EPIC microarrays. Tumor-infiltrating lymphocytes (TILs) and programmed cell death ligand 1 (PD-L1) expression were analyzed employing immunohistochemistry staining. Methylation profile, TIL density and PD-L1 expression were correlated with best radiological response to ICI treatment. Results: 29 patients (median age of 61; range 28-80) years; 8 (27.6%) females, 21 (72.4%) males) with HNSCC were included. Median number of prior systemic therapies was 1 (range 0-3). Median number of ICI applications was 6 (range 1-45). 2/29 (6.9%) patients achieved an objective response (complete response or partial response) under anti-PD-1 therapy. Median progression-free survival (PFS) and median overall survival (OS) were 3.3 months (range 0-28.8) and 7.2 months (range 0-29.4), respectively. 7/29 (24.1%) patients were still alive and one of these patients was still on ICI therapy at data cut-off. Methylation analyses revealed a combination of methylation changes (both hypo- and hypermethylation) that was predictive for response to ICI. 11/27 (40.7%) patients had PD-L1 expressing tumor cells ( > 1% PD-L1 expression). Median density of CD8+ TILs was 423.49 cells/mm2 tumor (range 5.71-11528.43 cells/mm2) and median density of CD3+ TILs was 794.82 cells/mm2 tumor (range 1.68-8811.74 cells/mm2). There was no correlation of PD-L1 expression, density of CD8+ or CD3+ TILs with response or disease control (p > 0.05). Conclusions: In contrast to PD-L1 expression and TIL density, methylation profiles were associated with response to ICI treatment in HNSCC patients.

Lymphocyte-activation gene 3 (LAG-3) expression in the inflammatory microenvironment of glioma

2553

Background: The blockade of lymphocyte-activation gene 3 (LAG-3), an inhibitory receptor on tumor-infiltrating lymphocytes, is currently under investigation in many extracranial tumor entities. Methods: 54 patients with diffuse glioma were included: 35 patients with glioblastoma (GBM, median age at diagnosis: 61 years) as well as 14 with WHO grade II and 5 with WHO grade III glioma (lower-grade glioma, LGG, median age at diagnosis: 45 years). Isocitrate dehydrogenase 1/2 mutations (IDH-mt) were present in 17/54 patients and 37/54 patients had IDH wildtype (IDH-wt) tumors. LAG-3 expression on tumor-infiltrating lymphocytes (TILs) was analyzed by immunohistochemistry (monoclonal anti-LAG-3 antibody, clone 17B4, LSBio Inc.). Results: LAG-3+ TILs could be observed in 5/54 (9.3%) samples, while CD3+ TILs were present in 32/54 (59.3%) and CD8+ TILs in 24/54 (44.4%) samples. Only IDH-wt glioma presented with LAG-3+ TILs (p = 0.168). Samples with LAG-3+ TILs presented with a numerical trend towards higher presence of CD3+ (5/27 CD3+ vs. 0/22 CD3−, p = 0.072) and CD8+ TILs (4/24 CD8+ vs. 1/30 CD8−, p = 0.159). 4/7 (57.1%) samples presenting with PD-1+ TILs also presented with LAG-3+ TILs (p = 0.001). Furthermore, glioma samples with LAG3+ TILs presented with higher expression of PD-L1 (median: 1% vs. 0%; p = 0.166). There was no difference in overall survival (OS) according to LAG-3+ TIL infiltration (median OS in LAG-3+: 21.7 months vs. LAG-3−: 41.4 months, p > 0.05). Conclusions: LAG-3+ TILs are rarely observed in IDH-wt and absent in IDH-mt glioma. Gliomas with an active inflammatory microenvironment present more frequently with LAG3+ TILs. The diverse composition of the inflammatory microenvironment and particular inflammatory subgroups should be considered in future clinical trials on immune-modulating therapies in glioma.

Abstract 4257: Genome-wide CpG island methylation analysis identifies tumor specifically methylated genes in non-small cell lung cancer patients

DNA methylation is part of the epigenetic gene regulation complex and it has been shown that methylation of certain genes occurs frequently in non-small cell lung cancers (NSCLC). We performed a genome-wide search for methylated CpG islands in primary tumors and corresponding non-malignant lung tissue samples of 101 stage I-III NSCLC patients by combining methylated DNA immunoprecipitation and microarray analysis using NimbleGen's 385K Human CpG Island plus Promoter arrays (MeDIP-chip). To test for differences in methylation between tumors and corresponding non-malignant lung tissues, we calculated paired t-statistics with permutation adjusted p-values for step down multiple testing. Overall, we identified 2.414 genomic positions differentially methylated between tumor and corresponding non-malignant lung tissue samples by MeDIP-chip analyses. Ninety-seven % of them were found to be tumor-specifically methylated. Annotation of these genomic positions resulted in the identification of 477 tumor-specifically methylated genes. These genes were classified according to Gene Ontology (GO) categories and over-representation of certain GO terms was calculated. Interestingly, we found that a large number of tumor-specifically methylated genes act as regulators of gene expression or mediate homophilic cell adhesion. Tumor-specific methylation of selected genes was confirmed by methylation-sensitive high-resolution melting analysis and ROC curve analyses revealed that primary tumors may be distinguished from non-malignant lung tissue samples by methylation of certain genes. In addition, in the majority of tumors methylation of certain genes was associated with loss of their protein expression determined by immunohistochemistry. Moreover, treatment of NSCLC cells with epigenetically active drugs resulted in upregulated expression of many tumor-specifically methylated genes analysed by gene expression microarrays. In conclusion, we identified a large number of tumor-specifically methylated genes in NSCLC patients. Expression of many of them is regulated by methylation. Overall, our findings emphasize the impact of methylation on the pathogenesis of NSCLCs.

Citation Format: Gerwin Heller, Valerie Babinsky, Barbara Ziegler, Marlene Weinzierl, Christian Noll, Corinna Altenberger, Leonhard Muellauer, Gerhard Dekan, Yuliya Grin, Gyoergy Lang, Adelheid End-Pfützenreuter, Irene Steiner, Sonja Zehetmayer, Balazs Doeme, Madeleine Arns, Kwun M. Fong, Casey M. Wright, Ian A. Yang, Walter Klepetko, Martin Posch, Christoph C. Zielinski, Sabine Zoechbauer-Mueller. Genome-wide CpG island methylation analysis identifies tumor specifically methylated genes in non-small cell lung cancer patients. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4257. doi:10.1158/1538-7445.AM2013-4257

Identification of basophils as a major source of hepatocyte growth factor in chronic myeloid leukemia: a novel mechanism of BCR-ABL1-independent disease progression

Chronic myeloid leukemia (CML) is a hematopoietic neoplasm characterized by the Philadelphia chromosome and the related BCR-ABL1 oncoprotein. Acceleration of CML is usually accompanied by basophilia. Several proangiogenic molecules have been implicated in disease acceleration, including the hepatocyte growth factor (HGF). However, little is known so far about the cellular distribution and function of HGF in CML. We here report that HGF is expressed abundantly in purified CML basophils and in the basophil-committed CML line KU812, whereas all other cell types examined expressed only trace amounts of HGF or no HGF. Interleukin 3, a major regulator of human basophils, was found to promote HGF expression in CML basophils. By contrast, BCR-ABL1 failed to induce HGF synthesis in CML cells, and imatinib failed to inhibit expression of HGF in these cells. Recombinant HGF as well as basophil-derived HGF induced endothelial cell migration in a scratch wound assay, and these effects of HGF were reverted by an anti-HGF antibody as well as by pharmacologic c-Met inhibitors. In addition, anti-HGF and c-Met inhibitors were found to suppress the spontaneous growth of KU812 cells, suggesting autocrine growth regulation. Together, HGF is a BCR-ABL1-independent angiogenic and autocrine growth regulator in CML. Basophils are a unique source of HGF in these patients and may play a more active role in disease-associated angiogenesis and disease progression than has so far been assumed. Our data also suggest that HGF and c-Met are potential therapeutic targets in CML.

High expression of Dicer reveals a negative prognostic influence in certain subtypes of primary cutaneous T cell lymphomas

BACKGROUND

Aberrant expression of microRNAs (miRNAs) has been implicated in oncogenesis of various tumors and primary cutaneous T cell lymphomas. Dicer, a ribonuclease III-like enzyme is essential for miRNA processing.

OBJECTIVE

We initiated a retrospective study to characterize the alterations in the expression profile of Dicer in patients with primary cutaneous T cell lymphomas (CTCL).

METHODS

A total of 50 consecutive patients with primary CTCL were studied, with the majority having mycosis fungoides (n=34). Five patients had primary cutaneous CD 30+ anaplastic large cell lymphoma, four patients each had lymphomatoid papulosis and primary cutaneous CD4-positive small/medium T-cell lymphoma, one primary cutaneous γδ T cell lymphoma, one Sézary syndrome and another subcutaneous panniculitis-like T cell lymphoma of αβ-phenotype. Immunohistochemistry was performed on paraffin sections using a commercially available antibody against Dicer. Intensity of expression was correlated with clinical parameters including disease specific survival (DSS) and time to progression (TTP).

RESULTS

After a median follow-up of 74 months (range: 1-271), 12/50 patients (24%) have died. Univariate and multivariate analysis for disease-specific survival showed Dicer expression and stage as a negative predictive factor in the sole group of MF patients (n=34) as well as in the heterogeneous group of patients (n=50), but not gender, histological subtype, primary localization of disease, age and recurrence of lymphoma (p>0.05).

CONCLUSION

Our data suggest Dicer expression as a possible molecular marker in patients with MF and apparently indicate that miRNA(s) might be of clinical relevance in CTCL.

Detection of gastric MALT lymphoma spreading to the small bowel by enteroscopy

Mucosa-associated lymphoid tissue (MALT) lymphoma is thought to be a multifocal disease with sometimes synchronous involvement of various mucosal structures. In this study we aimed to evaluate the potential involvement of the small bowel in patients suffering from gastric MALT lymphoma by analyzing the results of enteroscopy, a technique that allows easy and safe access to the small bowel with the potential for histological assessment of biopsy samples. We have retrospectively evaluated 347 enteroscopies and found nine patients with gastric MALT lymphoma who had undergone push enteroscopy with serial biopsies during staging. All patients tolerated enteroscopy without side effects, and no local complications occurred. In eight cases no evidence of duodenal or jejunal involvement was found macroscopically or by histological assessment of biopsies, while in one patient enteroscopy revealed jejunal MALT lymphoma infiltration with macroscopic accentuation of mucosal parts and consecutive histopathological verification more distal than 50 cm. This single-center retrospective analysis shows that enteroscopy can provide additional diagnostic information in patients with gastric MALT lymphoma, although the number of patients was small and only one out of nine patients showed hitherto undetected MALT lymphoma deposits. Further studies may quantify the additional diagnostic yield provided by this easy and safe endoscopic method.

90Y-ibritumomab tiuxetan (Zevalin) in heavily pretreated patients with mucosa associated lymphoid tissue lymphoma

Radioimmunotherapy using (90)Y-ibritumomab tiuxetan has predominantly been used in patients with follicular lymphoma, but little is known about its activity in patients with extranodal marginal zone lymphoma of the mucosa associated lymphoid tissue (MALT). A total of six patients progressing/relapsing following conventional therapy for MALT lymphoma were treated with (90)Y-ibritumomab tiuxetan at our institution. Two patients had gastric MALT lymphoma, one suffered from orbital MALT lymphoma, and two had cutaneous MALT lymphoma, while one patient had a widely disseminated lymphoma involving the stomach, lungs, lymph nodes, and salivary glands. All patients were at least in third relapse following various forms of therapy including Helicobacter pylori-eradication, radiation, chemotherapy, and application of rituximab. Following two doses of rituximab at 250 mg/m(2) at an interval of 1 week, (90)Y-ibritumomab tiuxetan was given immediately at a dose of 0.4 mCi/kg body weight. Treatment was well tolerated apart from one episode of pneumonia requiring hospitalization. Four patients developed a complete remission (ongoing now for 4, 16, 23, and 24 months), one patient had a partial response lasting for 5 months, and one patient had stable disease for 13 months. After a follow-up of 9-29 months, all patients are alive. Application of (90)Y-ibritumomab tiuxetan is active and safe in heavily pretreated patients with MALT lymphoma.

Assessment of the role of hepatitis C, Helicobacter pylori and autoimmunity in MALT lymphoma of the ocular adnexa in 45 Austrian patients

INTRODUCTION

A recent series from Italy has suggested a pathogenic link between hepatitis C virus and MALT lymphoma of the ocular adnexa. The hypothesis of our study was to prove this concept in Austrian patients with MALT lymphoma of the ocular adnexa.

MATERIALS AND METHODS

A total of 45 patients presenting with MALT lymphoma of the ocular adnexa were assessed for the presence of infection with hepatitis A, B and C. Furthermore, extensive staging to evaluate the extent of disease along with analysis of Helicobacter pylori-infection, the presence or absence of autoimmune diseases (AD) and assessment of MALT-lymphoma specific genetic changes was performed.

RESULTS

Only 2/45 (4%) patients were tested positive for hepatitis C, while 10/45 (22%) had an underlying AD and 15/39 (38%) had HP infection. Chromosomal aberrations were detected in 19 (54%) of 35 patients analyzed. Disseminated disease was a significant risk factor for relapse (p=0.014).

DISCUSSION

Our series suggests that infection with hepatitis C is not a significant contributor to the pathogenesis of ocular adnexal MALT lymphoma in the Austrian population, while a substantial proportion of these patients suffer from autoimmune conditions.

Rituximab monotherapy for primary cutaneous B-cell lymphoma: response and follow-up in 16 patients

BACKGROUND

We have carried out a retrospective analysis to evaluate the therapeutic value of the anti-CD20 antibody rituximab in 16 consecutive patients with primary cutaneous CD20+ B-cell lymphomas.

PATIENTS AND METHODS

Sixteen patients (4 females, 12 males) with a median age of 54 years received systemic therapy with rituximab 375 mg/m(2) once weekly for four or six consecutive weeks. Eleven patients had primary cutaneous follicle center cell lymphoma and five patients had a primary cutaneous marginal zone B-cell lymphoma.

RESULTS

Of the 16 patients with PCBCL, 14 patients (87.5%) achieved complete remission (CR). In two patients, partial remission was obtained and additional focal radiotherapy was applied, which resulted in final CR. Five to 14 (35%) patients with CR relapsed, in an interval between 6 and 37 months. There were no severe side-effects.

CONCLUSIONS

On the basis of our results, single-agent treatment with i.v. rituximab appears to be feasible and safe and results in a high rate of durable remissions. Judging from our data, it appears to be an attractive treatment option and should be directly compared with local radiotherapy.

Expression of Vascular Endothelial Growth Factor and its Receptors in Canine Lymphoma

Vascular endothelial growth factor (VEGF) stimulates endothelial cell proliferation and has a pivotal role in tumour angiogenesis. The expression of VEGF and its receptors VEGFR-1 and VEGFR-2 was examined immunohistochemically in 43 specimens of canine lymphoma and in six normal lymph nodes. Western blotting and reverse transcriptase polymerase chain reaction (RT-PCR) were performed to detect VEGF protein and mRNA, respectively. VEGF protein was expressed by 60% of the tumours with diffuse cytoplasmic labelling of the neoplastic cells. Endothelial cells, macrophages and plasma cells were also immunolabelled. VEGFR-1 was expressed by variable numbers of neoplastic cells in 54% of lymphoma specimens. VEGFR-1 was also expressed by macrophages, plasma cells, reticulum cells, and vascular endothelial cells. Macrophages and lymphocytes in germinal centres of normal lymph nodes were also immunoreactive with anti-VEGF and VEGFR-1. Most tumours did not express VEGFR-2 but in 7% of sections there was focal labelling of neoplastic and endothelial cells, with a cytoplasmic and perinuclear pattern. The observed variability in expression of VEGF and its receptors probably relates to the fact that lymphoma is a heterogeneous lymphoproliferative tumour. Individual differences in VEGF and VEGFR expression must be taken into account when VEGF and VEGFR-targeted approaches for anti-angiogenic therapy are considered in dogs.