Image-guided metabolomics and transcriptomics reveal tumour heterogeneity in luminal A and B human breast cancer beyond glucose tracer uptake.

BACKGROUND: Breast cancer is a metabolically heterogeneous disease, and although the concept of heterogeneous cancer metabolism is known, its precise role in human breast cancer is yet to be fully elucidated. METHODS: We investigated in an explorative approach a cohort of 42 primary mamma carcinoma patients with positron emission tomography/magnetic resonance imaging (PET/MR) prior to surgery, followed by histopathology and molecular diagnosis. From a subset of patients, which showed high metabolic heterogeneity based on tracer uptake and pathology classification, tumour centre and periphery specimen tissue samples were further investigated by a targeted breast cancer gene expression panel and quantitative metabolomics by nuclear magnetic resonance (NMR) spectroscopy. All data were analysed in a combinatory approach. RESULTS: [18 F]FDG (2-deoxy-2-[fluorine-18]fluoro-d-glucose) tracer uptake confirmed dominance of glucose metabolism in the breast tumour centre, with lower levels in the periphery. Additionally, we observed differences in lipid and proliferation related genes between luminal A and B subtypes in the centre and periphery. Tumour periphery showed elevated acetate levels and enrichment in lipid metabolic pathways genes especially in luminal B. Furthermore, serine was increased in the periphery and higher expression of thymidylate synthase (TYMS) indicated one-carbon metabolism increased in tumour periphery. The overall metabolic activity based on [18 F]FDG uptake of luminal B subtype was higher than that of luminal A and the difference between the periphery and centre increased with tumour grade. CONCLUSION: Our analysis indicates variations in metabolism among different breast cancer subtypes and sampling locations which details the heterogeneity of the breast tumours. Correlation analysis of [18 F]FDG tracer uptake, transcriptome and tumour metabolites like acetate and serine facilitate the search for new candidates for metabolic tracers and permit distinguishing luminal A and B. This knowledge may help to differentiate subtypes preclinically or to provide patients guide for neoadjuvant therapy and optimised surgical protocols based on individual tumour metabolism.

[Molecular diagnostics for vitreoretinal lymphoma]. / Molekulare Diagnostik des vitreoretinalen Lymphoms.

Primary vitreoretinal lymphoma (PVRL) represents a subtype of intraocular lymphomas, which are a subgroup of malignant lymphomas of the eye. PVRL is considered a special form of primary diffuse large cell lymphoma (DLBCL) of the CNS (central nervous system) (PCNSL) and arises primary or secondary to PCNSL. According to the cell of origin (COO) classification of DLBCL, PVRL largely belongs to the activated B­cell (ABC) type of DLBCL. Based on a recently established genetic-biological classification of DLBCL, PCNSL and thus also PVRL belong to a group of DLBCL of the MYD88/CD79B-mutated (MCD) or cluster 5 subtype, which often shows extranodal manifestations and MYD88 and CD79A mutations as well as CDKN2A deletions.PVRL diagnostics is often complicated as it represents a classic masquerade syndrome. Due to the usually limited material with often large numbers of reactive lymphocytes and/or degenerative changes in the cells, the results of diagnostic tests are difficult to interpret. Classic diagnostic tests include cytology on vitreous aspirates, immunocytochemistry, and clonality analysis.New insights into the spectrum of genetic alterations of vitreoretinal lymphomas (VRL) confirm the close relationship to PCNSL and could significantly improve pathological diagnosis. Next-generation sequencing panel-based diagnostics allow VRL diagnosis confirmation with little DNA in almost 100% of patients in cases with insufficient cytological evidence or lack of clonality detection. PVRL, as well as secondary vitreoretinal lymphomas after PCNSL or extracerebral DLBCL, have high mutation frequencies in characteristically mutated genes in PCNSL or MCD/cluster 5 type DLBCL. Supporting diagnostics, mutation detection can also be performed on cell-free DNA from the vitreous supernatant.

UV-radiation and MC1R germline mutations are risk factors for the development of conventional and spitzoid melanomas in children and adolescents.

BACKGROUND: Genomic characterisation has led to an improved understanding of adult melanoma. However, the aetiology of melanoma in children is still unclear and identifying the correct diagnosis and therapeutic strategies remains challenging. METHODS: Exome sequencing of matched tumour-normal pairs from 26 paediatric patients was performed to study the mutational spectrum of melanomas. The cohort was grouped into different categories: spitzoid melanoma (SM), conventional melanoma (CM), and other melanomas (OT). FINDINGS: In all patients with CM (n = 10) germline variants associated with melanoma were found in low to moderate melanoma risk genes: in 8 patients MC1R variants, in 2 patients variants in MITF, PTEN and BRCA2. Somatic BRAF mutations were detected in 60% of CMs, homozygous deletions of CDKN2A in 20%, TERTp mutations in 30%. In the SM group (n = 12), 5 patients carried at least one MC1R variant; somatic BRAF mutations were detected in 8.3%, fusions in 25% of the cases. No SM showed a homozygous CDKN2A deletion nor a TERTp mutation. In 81.8% of the CM/SM cases the UV damage signatures SBS7 and/or DBS1 were detected. The patient with melanoma arising in giant congenital nevus (CNM) demonstrated the characteristic NRAS Q61K mutation. INTERPRETATION: UV-radiation and MC1R germline variants are risk factors in the development of conventional and spitzoid paediatric melanomas. Paediatric CMs share genomic similarities with adult CMs while the SMs differ genetically from the CM group. Consistent genetic characterization of all paediatric melanomas will potentially lead to better subtype differentiation, treatment, and prevention in the future. FUNDING: Found in Acknowledgement.

A significant proportion of classic Hodgkin lymphoma recurrences represents clonally unrelated second primary lymphoma.

Despite high cure rates in classic Hodgkin lymphoma (cHL), relapses are observed. Whether relapsed cHL represents second primary lymphoma or an underlying T-cell lymphoma (TCL) mimicking cHL is underinvestigated. To analyze the nature of cHL recurrences, in-depth clonality testing of immunoglobulin (Ig) and T-cell receptor (TCR) rearrangements was performed in paired cHL diagnoses and recurrences among 60 patients, supported by targeted mutation analysis of lymphoma-associated genes. Clonal Ig rearrangements were detected by next-generation sequencing (NGS) in 69 of 120 (58%) diagnoses and recurrence samples. The clonal relationship could be established in 34 cases, identifying clonally related relapsed cHL in 24 of 34 patients (71%). Clonally unrelated cHL was observed in 10 of 34 patients (29%) as determined by IG-NGS clonality assessment and confirmed by the identification of predominantly mutually exclusive gene mutations in the paired cHL samples. In recurrences of >2 years, ∼60% of patients with cHL for whom the clonal relationship could be established showed a second primary cHL. Clonal TCR gene rearrangements were identified in 14 of 125 samples (11%), and TCL-associated gene mutations were detected in 7 of 14 samples. Retrospective pathology review with integration of the molecular findings were consistent with an underlying TCL in 5 patients aged >50 years. This study shows that cHL recurrences, especially after 2 years, sometimes represent a new primary cHL or TCL mimicking cHL, as uncovered by NGS-based Ig/TCR clonality testing and gene mutation analysis. Given the significant therapeutic consequences, molecular testing of a presumed relapse in cHL is crucial for subsequent appropriate treatment strategies adapted to the specific lymphoma presentation.

Fisetin overcomes non-targetability of mutated KRAS induced YB-1 signaling in colorectal cancer cells and improves radiosensitivity by blocking repair of radiation-induced DNA double-strand breaks.

BACKGROUND AND PURPOSE: KRAS is frequently mutated, and the Y-box binding protein 1 (YB-1) is overexpressed in colorectal cancer (CRC). Mutant KRAS (KRASmut) stimulates YB-1 through MAPK/RSK and PI3K/AKT, independent of epidermal growth factor receptor (EGFR). The p21-activated kinase (PAK) family is a switch-site upstream of AKT and RSK. The flavonoid compound fisetin inhibits RSK-mediated YB-1 signaling. We sought the most effective molecular targeting approach that interferes with DNA double strand break (DSB) repair and induces radiosensitivity of CRC cells, independent of KRAS mutation status. MATERIALS AND METHODS: KRAS activity and KRAS mutation were analyzed by Ras-GTP assay and NGS. Effect of dual targeting of RSK and AKT (DT), the effect of fisetin as well as targeting PAK by FRAX486 and EGFR by erlotinib on YB-1 activity was tested by Western blotting after irradiation in vitro and ex vivo. Additionally, the effect of DT and FRAX486 on DSB repair pathways was tested in cells expressing reporter constructs for the DSB repair pathways by flow cytometry analysis. Residual DSBs and clonogenicity were examined by γH2AX- and clonogenic assays, respectively. RESULTS: Erlotinib neither blocked DSB repair nor inhibited YB-1 phosphorylation under KRAS mutation condition in vitro and ex vivo. DT and FRAX486 effectively inhibited YB-1 phosphorylation independent of KRAS mutation status and diminished homologous recombination (HR) and alternative non-homologous end joining (NHEJ) repair. DT and FRAX486 inhibited DSB repair in CaCo2 but not in isogenic KRASG12V cells. Fisetin inhibited YB-1 phosphorylation, blocked DSB repair and increased radiosensitivity, independent of KRAS mutation status. CONCLUSION: Combination of fisetin with radiotherapy may improve CRC radiation response, regardless of KRASmut status.

Targeted NGS on sequential bone marrow biopsies aids in the evaluation of cytopenias and monocytosis and documents clonal evolution-a proof of principle study.

Differential diagnosis of clonal versus reactive cytopenia and monocytosis, respectively, frequently presents a diagnostic challenge. With the two recent classifications of myeloid disorders, mutational analysis has gained importance as a diagnostic tool. However, reports on its utility on trephine bone marrow biopsies (BMB) are sparse. The aim of our proof of principle study was to determine the suitability of targeted sequencing for the longitudinal evaluation of cytopenia and monocytosis and demonstration of clonal evolution on sequential BMB. Seventy-seven EDTA-decalcified BMB of 33 patients with peripheral cytopenia and/or monocytosis, including at least one follow-up biopsy/patient, were included. Initial morphological diagnoses were idiopathic cytopenia of undetermined significance (ICUS, 8 cases), MDS (without blast increase, 7 cases), MDS with increased blasts/excess blasts (MDS-IB/EB) (11 cases), and CMML (7 cases). Thirty-one genes relevant for myeloid disorders were examined using two custom AmpliSeq NGS panels. Mutations were found in the initial BMB of 5/8 cases of ICUS, thus changing the diagnosis to clonal cytopenia of unknown significance (CCUS), 5/7 MDS, 10/11 MDS-IB/EB, and 7/7 CMML. Clonal evolution was observed in 14/33 (42%) cases, mostly associated with disease progression. None of the wild-type patients acquired mutations during follow-up. NGS-based mutation profiling is a robust diagnostic tool for BMB and provides valuable additional information, especially for cases with no/minimal dysplasia, and for better risk stratification of MDS. Tracking variant allele frequency and appearance of mutations over time allows for observing clonal evolution or relapse.

Deep learning-based scoring of tumour-infiltrating lymphocytes is prognostic in primary melanoma and predictive to PD-1 checkpoint inhibition in melanoma metastases.

BACKGROUND: Recent advances in digital pathology have enabled accurate and standardised enumeration of tumour-infiltrating lymphocytes (TILs). Here, we aim to evaluate TILs as a percentage electronic TIL score (eTILs) and investigate its prognostic and predictive relevance in cutaneous melanoma. METHODS: We included stage I to IV cutaneous melanoma patients and used hematoxylin-eosin-stained slides for TIL analysis. We assessed eTILs as a continuous and categorical variable using the published cut-off of 16.6% and applied Cox regression models to evaluate associations of eTILs with relapse-free, distant metastasis-free, and overall survival. We compared eTILs of the primaries with matched metastasis. Moreover, we assessed the predictive relevance of eTILs in therapy-naïve metastases according to the first-line therapy. FINDINGS: We analysed 321 primary cutaneous melanomas and 191 metastatic samples. In simple Cox regression, tumour thickness (p < 0.0001), presence of ulceration (p = 0.0001) and eTILs ≤16.6% (p = 0.0012) were found to be significant unfavourable prognostic factors for RFS. In multiple Cox regression, eTILs ≤16.6% (p = 0.0161) remained significant and downgraded the current staging. Lower eTILs in the primary tissue was associated with unfavourable relapse-free (p = 0.0014) and distant metastasis-free survival (p = 0.0056). In multiple Cox regression adjusted for tumour thickness and ulceration, eTILs as continuous remained significant (p = 0.019). When comparing TILs in primary tissue and corresponding metastasis of the same patient, eTILs in metastases was lower than in primary melanomas (p < 0.0001). In therapy-naïve metastases, an eTILs >12.2% was associated with longer progression-free survival (p = 0.037) and melanoma-specific survival (p = 0.0038) in patients treated with anti-PD-1-based immunotherapy. In multiple Cox regression, lactate dehydrogenase (p < 0.0001) and eTILs ≤12.2% (p = 0.0130) were significantly associated with unfavourable melanoma-specific survival. INTERPRETATION: Assessment of TILs is prognostic in primary melanoma samples, and the eTILs complements staging. In therapy-naïve metastases, eTILs ≤12.2% is predictive of unfavourable survival outcomes in patients receiving anti-PD-1-based therapy. FUNDING: See a detailed list of funding bodies in the Acknowledgements section at the end of the manuscript.

Successful treatment of metastatic uveal melanoma with ipilimumab and nivolumab after severe progression under tebentafusp: a case report.

Metastatic uveal melanoma (UM) is a rare form of melanoma differing from cutaneous melanoma by etiology, prognosis, driver mutations, pattern of metastases and poor response rate to immune checkpoint inhibitors (ICI). Recently, a bispecific gp100 peptide-HLA-directed CD3 T cell engager, tebentafusp, has been approved for the treatment of HLA-A*02:01 metastatic or unresectable UM. While the treatment regime is complex with weekly administrations and close monitoring, the response rate is limited. Only a few data exist on combined ICI in UM after previous progression on tebentafusp. In this case report, we present a patient with metastatic UM who first suffered extensive progression under treatment with tebentafusp but in the following had an excellent response to combined ICI. We discuss possible interactions that could explain responsiveness to ICI after pretreatment with tebentafusp in advanced UM.

Detection of circulating cell-free HPV DNA of 13 HPV types for patients with cervical cancer as potential biomarker to monitor therapy response and to detect relapse.

BACKGROUND: HPV-related cervical cancer (CC) is the fourth most frequent cancer in women worldwide. Cell-free tumour DNA is a potent biomarker to detect treatment response, residual disease, and relapse. We investigated the potential use of cell-free circulating HPV-DNA (cfHPV-DNA) in plasma of patients with CC. METHODS: cfHPV-DNA levels were measured using a highly sensitive next-generation sequencing-based approach targeting a panel of 13 high-risk HPV types. RESULTS: Sequencing was performed in 69 blood samples collected from 35 patients, of which 26 were treatment-naive when the first liquid biopsy sample was retrieved. cfHPV-DNA was successfully detected in 22/26 (85%) cases. A significant correlation between tumour burden and cfHPV-DNA levels was observed: cfHPV-DNA was detectable in all treatment-naive patients with advanced-stage disease (17/17, FIGO IB3-IVB) and in 5/9 patients with early-stage disease (FIGO IA-IB2). Sequential samples revealed a decrease of cfHPV-DNA levels in 7 patients corresponding treatment response and an increase in a patient with relapse. CONCLUSIONS: In this proof-of-concept study we demonstrated the potential of cfHPV-DNA as a biomarker for therapy monitoring in patients with primary and recurrent CC. Our findings facilitate the development of a sensitive and precise, non-invasive, inexpensive, and easily accessible tool in CC diagnosis, therapy monitoring and follow-up.

FACILITATE: A real-world, multicenter, prospective study investigating the utility of a rapid, fully automated real-time PCR assay versus local reference methods for detecting epidermal growth factor receptor variants in NSCLC.

Accurate testing for epidermal growth factor receptor (EGFR) variants is essential for informing treatment decisions in non-small cell lung cancer (NSCLC). Automated diagnostic workflows may allow more streamlined initiation of targeted treatments, where appropriate, while comprehensive variant analysis is ongoing. FACILITATE, a real-world, prospective, multicenter, European study, evaluated performance and analytical turnaround time of the Idylla™ EGFR Mutation Test compared with local reference methods. Sixteen sites obtained formalin-fixed paraffin-embedded biopsy samples with ≥ 10% neoplastic cells from patients with NSCLC. Consecutive 5 µm sections from patient samples were tested for clinically relevant NSCLC-associated EGFR variants using the Idylla™ EGFR Mutation Test and local reference methods; performance (concordance) and analytical turnaround time were compared. Between January 2019 and November 2020, 1,474 parallel analyses were conducted. Overall percentage agreement was 97.7% [n = 1,418; 95% confidence interval (CI): 96.8-98.3], positive agreement, 87.4% (n = 182; 95% CI: 81.8-91.4) and negative agreement, 99.2% (n = 1,236; 95% CI: 98.5-99.6). There were 38 (2.6%) discordant cases. Ninety percent of results were returned with an analytical turnaround time of within 1 week using the Idylla™ EGFR Mutation Test versus ∼22 days using reference methods. The Idylla™ EGFR Mutation Test performed well versus local methods and had shorter analytical turnaround time. The Idylla™ EGFR Mutation Test can thus support application of personalized medicine in NSCLC.

Prevalence of IRF4 rearrangement in large B-cell lymphomas of the Waldeyer's ring in adults.

Diffuse large B-cell lymphoma (DLBCL) is the most common B-cell non-Hodgkin lymphoma (B-NHL) in adults. These lymphomas are classified according to gene expression profiling (GEP) into germinal center B-cell (GCB) and activated B-cell type (ABC). Recent studies have suggested new subtypes of large B-cell lymphoma, based on genetic and molecular alterations, among them is large B-cell lymphoma with IRF4-rearrangement (LBCL-IRF4). We used fluorescence in situ hybridization (FISH), GEP (using the DLBCL COO assay by HTG Molecular Inc), and next generation sequencing (NGS) to comprehensively characterize 30 cases of LBCLs located in Waldeyer's ring in adult patients and to identify LBCL-IRF4. FISH revealed breaks of IRF4 in 2/30 cases (6.7%), BCL2 breaks in 6/30 cases (20.0%), and IGH breaks in 13/29 cases (44.8%). GEP classified 14 cases each as GCB or ABC subtype, and 2 cases remained unclassified; this was concordant with the immunohistochemistry (IHC) in 25/30 cases (83.3%). A subgrouping, based on GEP, was performed: group 1 included 14 GCB cases with the most frequent mutations in BCL2 and EZH2 in 6/14 cases (42.8%). The two cases with IRF4 rearrangement were assigned to this group by GEP and showed IRF4 mutations, supporting the diagnosis of LBCL-IRF4. Group 2 included 14 ABC cases; the most frequent mutations were CD79B and MYD88 identified in 5/14 patients (35.7%). Group 3 included 2 unclassifiable cases in which no molecular patterns were detected. Overall, LBCLs of Waldeyer's ring in adult patients are a heterogeneous group, including LBCL-IRF4, which shares several features with cases in the pediatric population.

TMB and BRAF mutation status are independent predictive factors in high-risk melanoma patients with adjuvant anti-PD-1 therapy.

BACKGROUND: High tumor mutational burden (TMB) is associated with a favorable outcome in metastatic melanoma patients treated with immune checkpoint inhibitors. However, data are limited in the adjuvant setting. As BRAF mutated patients have an alternative with targeted adjuvant therapy, it is important to identify predictive factors for relapse and recurrence-free survival (RFS) in patients receiving adjuvant anti-PD-1 antibodies. METHODS: We evaluated 165 melanoma patients who started adjuvant anti-PD-1 antibody therapy at our center between March 2018 and September 2019. The initial tumor stage was assessed at the beginning of therapy according to the 8th edition of the AJCC Cancer Staging Manual. Tumor and normal tissue of the high-risk stages IIIC/D/IV were sequenced using a 700 gene NGS panel. RESULTS: The tumor stages at the beginning of adjuvant anti-PD-1 therapy were as follows: N = 80 stage IIIA/B (48%), N = 85 stage IIIC/D/IV (52%). 72/165 patients (44%) suffered a relapse, 44/72 (61%) with only loco regional and 28/72 (39%) with distant metastases. Sequencing results were available from 83 to 85 patients with stage IIIC/D/IV. BRAF mutation status (HR 2.12, 95% CI 1.12-4.08; p = 0.022) and TMB (HR 7.11, 95% CI 2.19-23.11; p = 0.001) were significant and independent predictive factors for relapse-free survival (RFS). CONCLUSION: BRAF mutation status and TMB were independent predictive factors for RFS. Patients with BRAF V600E/K mutation and TMB high had the best outcome. A classification based on BRAF mutation status and TMB is proposed to predict RFS in melanoma patients with adjuvant anti-PD-1 therapy.

Germline findings in patients with advanced malignancies screened with paired blood-tumour testing for personalised treatment approaches.

BACKGROUND: Sequencing of tumour tissue with comprehensive gene panels is increasingly used to guide treatment in precision oncology. Analysis of tumour-normal pairs allows in contrast to tumour-only assessment direct discrimination between somatic and germline alterations, which might have important implications not only for the patients but also their families. METHODS: We performed tumour normal sequencing with a large gene panel in 1048 patients with advanced cancer to support treatment decision. Sequencing results were correlated with clinical and family data. RESULTS: We identified 156 likely pathogenic or pathogenic (LP/P) germline variants in cancer predisposition genes (CPGs) in 144 cases (13.7%). Of all patients, 8.8% had a LP/P variant in autosomal-dominant cancer predisposition genes (AD-CPGs), most of them being genes with high or moderate penetrance (ATM, BRCA2, CHEK2 and BRCA1). In 48 cases, the P/LP variant matched the expected tumour spectrum. A second variant in tumour tissue was found in 31 patients with AD-CPG variants. Low frequency mutations in either TP53, ATM or DNMT3A in the normal sample indicated clonal haematopoiesis in five cases. CONCLUSIONS: Tumour-normal testing for personalised treatment identifies germline LP/P variants in a relevant proportion of patients with cancer. The majority of them would not have been referred to genetic counselling based on family history. Indirect functional readouts of tumour-normal sequencing can provide novel links between CPGs and unexpected cancers. The interpretation of increasingly complex datasets in precision oncology is challenging and concepts of interdisciplinary personalised cancer prevention are needed to support patients and their families.

Cuprizone feeding induces swollen astrocyte endfeet.

The cuprizone model is a widely used model to study the pathogenesis of multiple sclerosis (MS). Due to the selective loss of mature oligodendrocytes and myelin, it is mainly being used to study demyelination and the mechanisms of remyelination, as well as the efficiency of compounds or therapeutics aiming at remyelination. Although early investigations using high dosages of cuprizone reported the occurrence of hydrocephalus, it has long been assumed that cuprizone feeding at lower dosages does not induce changes at the blood-brain barrier (BBB). Here, by analyzing BBB ultrastructure with high-resolution electron microscopy, we report changes at astrocytic endfeet surrounding vessels in the brain parenchyma. Particularly, edema formation around blood vessels and swollen astrocytic endfeet already occurred after feeding low dosages of cuprizone. These findings indicate changes in BBB function that will have an impact on the milieu of the central nervous system (CNS) in the cuprizone model and need to be considered when studying the mechanisms of de- and remyelination.

The oncogenic fusion protein DNAJB1-PRKACA can be specifically targeted by peptide-based immunotherapy in fibrolamellar hepatocellular carcinoma.

The DNAJB1-PRKACA fusion transcript is the oncogenic driver in fibrolamellar hepatocellular carcinoma, a lethal disease lacking specific therapies. This study reports on the identification, characterization, and immunotherapeutic application of HLA-presented neoantigens specific for the DNAJB1-PRKACA fusion transcript in fibrolamellar hepatocellular carcinoma. DNAJB1-PRKACA-derived HLA class I and HLA class II ligands induce multifunctional cytotoxic CD8+ and T-helper 1 CD4+ T cells, and their cellular processing and presentation in DNAJB1-PRKACA expressing tumor cells is demonstrated by mass spectrometry-based immunopeptidome analysis. Single-cell RNA sequencing further identifies multiple T cell receptors from DNAJB1-PRKACA-specific T cells. Vaccination of a fibrolamellar hepatocellular carcinoma patient, suffering from recurrent short interval disease relapses, with DNAJB1-PRKACA-derived peptides under continued Poly (ADP-ribose) polymerase inhibitor therapy induces multifunctional CD4+ T cells, with an activated T-helper 1 phenotype and high T cell receptor clonality. Vaccine-induced DNAJB1-PRKACA-specific T cell responses persist over time and, in contrast to various previous treatments, are accompanied by durable relapse free survival of the patient for more than 21 months post vaccination. Our preclinical and clinical findings identify the DNAJB1-PRKACA protein as source for immunogenic neoepitopes and corresponding T cell receptors and provide efficacy in a single-patient study of T cell-based immunotherapy specifically targeting this oncogenic fusion.

[Lymphoma of the eye and its adnexa : Modern pathological diagnostics and systemic treatment]. / Lymphome des Auges und seiner Adnexe : Moderne pathologische Diagnostik und systemische Therapie.

BACKGROUND: Malignant lymphomas of the eye and its adnexal structures account for approximately 5-15% of extranodal lymphomas. According to anatomic and biological criteria, two large groups of lymphomas in and around the eye need to be distinguished: (1) primary lymphomas of intraocular structures and (2) primary lymphomas of ocular adnexa. Furthermore, there is a large spectrum of secondary manifestations of malignant lymphomas in ocular and periocular structures. OBJECTIVE: This article gives a summary of the classification and molecular pathology of various intraocular and periocular lymphomas as well as oncological systemic treatment with a focus on primary vitreoretinal lymphomas. METHODS: A selective literature search was carried out in PubMed on the topic of intraocular and periocular lymphomas and own experiences are presented. RESULTS: The treatment of primary vitreoretinal lymphomas (PVRL) is an interdisciplinary challenge and despite the apparently localized disease, systemic treatment concepts are necessary to reduce the high risk of secondary involvement of the central nervous system (CNS). Therefore, it is crucial that the substances used can penetrate the CNS, and protocols should be chosen in accordance with the treatment concepts for primary CNS lymphomas. The knowledge on the genetics and biology of ocular lymphomas generated by modern high throughput methods enable not only improved diagnostics using molecular methods but also provide rationales for targeted therapeutic approaches. CONCLUSION: A deep understanding of the biological and molecular principles of intraocular and periocular lymphomas forms a basic prerequisite for precise diagnostics and the use of targeted systemic treatment.

Multiparametric Classification of Non-Muscle Invasive Papillary Urothelial Neoplasms: Combining Morphological, Phenotypical, and Molecular Features for Improved Risk Stratification.

Diagnosis and grading of non-invasive papillary urothelial tumors according to the current WHO classification poses some challenges for pathologists. The diagnostic reproducibility of separating low-grade and high-grade lesions is low, which impacts their clinical management. Whereas papillary urothelial neoplasms with low malignant potential (PUN-LMP) and low-grade papillary non-invasive carcinoma (LG-PUC) are comparable and show frequent local recurrence but rarely metastasize, high-grade papillary non-invasive carcinoma (HG-PUC) has a poor prognosis. The main objective of this work is to develop a multiparametric classification to unambiguously distinguish low-grade and high-grade tumors, considering immunohistochemical stains for p53, FGFR3, CK20, MIB-1, p16, p21 and p-HH3, and pathogenic mutations in TP53, FGFR3, TP53, ERCC2, PIK3CA, PTEN and STAG2. We reviewed and analyzed the clinical and histological data of 45 patients with a consensus diagnosis of PUN-LMP (n = 8), non-invasive LG-PUC (n = 23), and HG-PUC (n = 14). The proliferation index and mitotic count assessed with MIB-1 and P-HH3 staining, respectively correlated with grading and clinical behavior. Targeted sequencing confirmed frequent FGFR3 mutations in non-invasive papillary tumors and identified mutations in TP53 as high-risk. Cluster analysis of the different immunohistochemical and molecular parameters allowed a clear separation in two different clusters: cluster 1 corresponding to PUN-LMP and LG-PUC (low MIB-1 and mitotic count/FGFR3 and STAG2 mutations) and cluster 2, HG-PUC (high MIB-1 and mitosis count/CK20 +++ expression, FGFR3 WT and TP53 mutation). Further analysis is required to validate and analyze the reproducibility of these clusters and their biological and clinical implication.

CD147 a direct target of miR-146a supports energy metabolism and promotes tumor growth in ALK+ ALCL.

We recently reported that miR-146a is differentially expressed in ALK+ and ALK- anaplastic large cell lymphoma (ALCL). In this study, the downstream targets of miR-146a in ALK+ ALCL were investigated by transcriptome analysis, identifying CD147 as potential target gene. Because CD147 is differentially expressed in ALK+ ALCL versus ALK- ALCL and normal T cells, this gene emerged as a strong candidate for the pathogenesis of this tumor. Here we demonstrate that CD147 is a direct target of miR-146 and contributes to the survival and proliferation of ALK+ ALCL cells in vitro and to the engraftment and tumor growth in vivo in an ALK+ ALCL-xenotransplant mouse model. CD147 knockdown in ALK+ ALCL cells resulted in loss of monocarboxylate transporter 1 (MCT1) expression, reduced glucose consumption and tumor growth retardation, as demonstrated by [18F]FDG-PET/MRI analysis. Investigation of metabolism in vitro and in vivo supported these findings, revealing reduced aerobic glycolysis and increased basal respiration in CD147 knockdown. In conclusion, our findings indicate that CD147 is of vital importance for ALK+ ALCL to maintain the high energy demand of rapid cell proliferation, promoting lactate export, and tumor growth. Furthermore, CD147 has the potential to serve as a novel therapeutic target in ALK+ ALCL, and warrants further investigation.

A unifying hypothesis for PNMZL and PTFL: morphological variants with a common molecular profile.

Pediatric nodal marginal zone lymphoma (PNMZL) is an uncommon B-cell neoplasm affecting mainly male children and young adults. This indolent lymphoma has distinct characteristics that differ from those of conventional nodal marginal zone lymphoma (NMZL). Clinically, it exhibits overlapping features with pediatric-type follicular lymphoma (PTFL). To explore the differences between PNMZL and adult NMZL and its relationship to PTFL, a series of 45 PNMZL cases were characterized morphologically and genetically by using an integrated approach; this approach included whole-exome sequencing in a subset of cases, targeted next-generation sequencing, and copy number and DNA methylation arrays. Fourteen cases (31%) were diagnosed as PNMZL, and 31 cases (69%) showed overlapping histologic features between PNMZL and PTFL, including a minor component of residual serpiginous germinal centers reminiscent of PTFL and a dominant interfollicular B-cell component characteristic of PNMZL. All cases displayed low genomic complexity (1.2 alterations per case) with recurrent 1p36/TNFRSF14 copy number-neutral loss of heterozygosity alterations and copy number loss (11%). Similar to PTFL, the most frequently mutated genes in PNMZL were MAP2K1 (42%), TNFRSF14 (36%), and IRF8 (34%). DNA methylation analysis revealed no major differences between PTFL and PNMZL. Genetic alterations typically seen in conventional NMZL were absent in PNMZL. In summary, overlapping clinical, morphologic, and molecular findings (including low genetic complexity; recurrent alterations in MAP2K1, TNFRSF14, and IRF8; and similar methylation profiles) indicate that PNMZL and PTFL are likely part of a single disease with variation in the histologic spectrum. The term "pediatric-type follicular lymphoma with and without marginal zone differentiation" is suggested.

The molecular hallmarks of primary and secondary vitreoretinal lymphoma.

Vitreoretinal lymphoma (VRL) is a rare subtype of diffuse large B-cell lymphoma (DLBCL) considered a variant of primary central nervous system lymphoma (PCNSL). The diagnosis of VRL requires examination of vitreous fluid, but cytologic differentiation from uveitis remains difficult. Because of its rarity and the difficulty in obtaining diagnostic material, little is known about the genetic profile of VRL. The purpose of our study was to investigate the mutational profile of a large series of primary and secondary VRL. Targeted next-generation sequencing using a custom panel containing the most frequent mutations in PCNSL was performed on 34 vitrectomy samples from 31 patients with VRL and negative controls with uveitis. In a subset of cases, genome-wide copy number alterations (CNAs) were assessed using the OncoScan platform. Mutations in MYD88 (74%), PIM1 (71%), CD79B (55%), IGLL5 (52%), TBL1XR1 (48%), ETV6 (45%), and 9p21/CDKN2A deletions (75%) were the most common alterations, with similar frequencies in primary (n = 16), synchronous (n = 3), or secondary (n = 12) VRL. This mutational spectrum is similar to MYD88mut/CD79Bmut (MCD or cluster 5) DLBCL with activation of Toll-like and B-cell receptor pathways and CDKN2A loss, confirming their close relationship. OncoScan analysis demonstrated a high number of CNAs (mean 18.6 per case). Negative controls lacked mutations or CNAs. Using cell-free DNA of vitreous fluid supernatant, mutations present in cellular DNA were reliably detected in all cases examined. Mutational analysis is a highly sensitive and specific tool for the diagnosis of VRL and can also be applied successfully to cell-free DNA derived from the vitreous.