Radiosensitizing Favors Response to Peptide Receptor Radionuclide Therapy in Patients With Highly Proliferative Neuroendocrine Malignancies: Preliminary Evidence From a Clinical Pilot Study

AIM/INTRODUCTION

Peptide receptor radionuclide therapy (PRRT) represents a cornerstone of treatment regimens for patients with low proliferative neuroendocrine tumors (NETs). However, in patients experiencing somatostatin receptor-positive NET with higher proliferation rates, a value and potential therapeutic benefit of PRRT as part of multimodal treatment approaches and potentially with addition of radiosensitizing agents has not yet been established.

PATIENTS AND METHODS

In this study, 20 patients with histologically confirmed gastroenteropancreatic (GEP) NET with proliferation rates (Ki67) between 15% and 55% were treated either with PRRT only (n = 10) or with a combination therapy (n = 10) comprising PRRT and capecitabine/temozolomide (CAP/TEM) for at least 2 consecutive cycles.

RESULTS

Disease control rate in patients treated with PRRT alone was 60% (40% stable disease and 20% partial response). Strikingly, in patients treated with PRRT in combination with radiosensitization (CAP/TEM), the disease control rate was 90% (20% stable disease and 70% partial response). The median progression-free survival in the PRRT only group was 12 months, whereas the median progression-free survival in the PRRT + CAP/TEM group was 26 months and has not been yet reached for all patients in the group during the observation period. The median disease-specific survival for patients with PRRT alone was 51 months, whereas this end point was not yet reached in the PRRT + CAP/TEM group. Moreover, the PRRT + CAP/TEM group showed a significantly higher reduction of SSTR-PET-based metabolic tumor volume and chromogranin A levels compared with the PRRT only group. Importantly, adverse events of all grades did not differ between both groups.

CONCLUSIONS

PRRT + CAP/TEM represents a highly promising and well-tolerated therapeutic regimen for patients experiencing somatostatin receptor-positive NET with higher (Ki67 ≥ 15%) proliferation rate. Prospective randomized clinical trials are warranted.

A novel approach to guide GD2-targeted therapy in pediatric tumors by PET and [64Cu]Cu-NOTA-ch14.18/CHO

Background: The tumor-associated disialoganglioside GD2 is a bona fide immunotherapy target in neuroblastoma and other childhood tumors, including Ewing sarcoma and osteosarcoma. GD2-targeting antibodies proved to be effective in neuroblastoma and GD2-targeting chimeric antigen receptors (CAR)- expressing T cells as well as natural killer T cells (NKTs) are emerging. However, assessment of intra- and intertumoral heterogeneity has been complicated by ineffective immunohistochemistry as well as sampling bias in disseminated disease. Therefore, a non-invasive approach for the assessment and visualization of GD2 expression in-vivo is of upmost interest and might enable a more appropriate treatment stratification. Methods: Recently, [64Cu]Cu-NOTA-ch14.18/CHO (64Cu-GD2), a radiolabeled GD2-antibody for imaging with Positron-Emission-Tomography (PET) was developed. We here report our first clinical patients' series (n = 11) in different pediatric tumors assessed with 64Cu-GD2 PET/MRI. GD2-expression in tumors and tissue uptake in organs was evaluated by semiquantitative measurements of standardized uptake values (SUV) with PET/MRI on day 1 p.i. (n = 11) as well as on day 2 p.i. (n = 6). Results: In 8 of 9 patients with suspicious tumor lesions on PET/MRI at least one metastasis showed an increased 64Cu-GD2 uptake and a high tracer uptake (SUVmax > 10) was measured in 4 of those 8 patients. Of note, sufficient image quality with high tumor to background contrast was readily achieved on day 1. In case of 64Cu-GD2-positive lesions, an excellent tumor to background ratio (at least 6:1) was observed in bones, muscles or lungs, while lower tumor to background contrast was seen in the spleen, liver and kidneys. Furthermore, we demonstrated extensive tumor heterogeneity between patients as well as among different metastatic sites in individual patients. Dosimetry assessment revealed a whole-body dose of only 0.03 mGy/MBq (range 0.02-0.04). Conclusion: 64Cu-GD2 PET/MRI enables the non-invasive assessment of individual heterogeneity of GD2 expression, which challenges our current clinical practice of patient selection, stratification and immunotherapy application scheme for treatment with anti-GD2 directed therapies.

Treatment modalities favoring outcome in well-differentiated neuroendocrine tumors G3

Introduction

Neuroendocrine neoplasms (NEN) are a rare and heterogenous group of tumors arising from neuroendocrine cells in multiple organs. Neuroendocrine tumors (NET) G3 encompass a small subgroup accounting for less than 10% of all neuroendocrine neoplasms. In contrast to NET G1 and G2 as well as neuroendocrine carcinomas (NEC), in NET G3 data on treatment and patient outcomes are still limited. Especially in a metastasized tumor stage, the role of surgery, peptide receptor radionucleotide therapy (PRRT), and systemic chemotherapy is not clearly defined.

Methods

In this real-life cohort, we consecutively analyzed clinical outcome in NET G3 patients receiving different diagnostic and treatment.

Results and discussion

We found that even metastasized NET G3 patients undergoing surgery, or receiving radiation, somatostatin analogues (SSA), and PRRT showed a clear survival benefit. Interestingly, all treatment regimen were superior to classical chemotherapeutic agents. In addition, somatostatin receptor (SSTR) PET-CT, FDG PET-CT, and repetitive biopsies were shown to be useful diagnostic and prognostic tools in NET G3. Our study demonstrates that patients with highly proliferative NET G3 might benefit from less aggressive treatment modalities commonly used in low proliferative NEN.

Female Hyperplastic PSA-Positive Prostate Tissue in the Bladder Neck

INTRODUCTION

We report a rare case of Skene's gland hyperplasia where the serum prostate-specific antigen (PSA) level was measurable.

CASE PRESENTATION

The patient was a 91-year-old woman with a suspected bladder mass at the bladder trigone. Cystoscopy revealed a suspected lesion and an obstructed anterior bladder neck with a large mass located from a "7 o'clock" to "11 o'clock" area. The photodynamic diagnosis was negative. Transurethral subtotal resection of the mass was performed. The serum PSA level at the third postoperative day was 0.08 ng/mL. Postoperative cystography showed no contrast media extravasation. Thus, histopathology revealed massive adenomyomatous hyperplasia of the Skene's gland, as well as nondysplastic urothelium and glandular and squamous epithelium. Immunohistochemistry showed strong PSA and NKX3.1 positivity, confirming the diagnosis of "female prostate." FISH analysis showed only green signals that confirm an XX karyotype. In follow-up to 17 months, there was no disease recurrence or need for a urinary catheter.

CONCLUSION

Effective therapeutic strategies for these lesions are unknown due to the absence of reported cases. Given the patient's age, we assumed that bladder neck resection by transurethral resection with a controlled level of serum PSA would be a suitable therapeutic approach.

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.

Myasthenia gravis as initial presentation of a pancreatic neuroendocrine tumor: A case report

Myasthenia gravis (MG) is a heterogeneous autoimmune disease, which is characterized by a postsynaptic neuromuscular transmission defect, with antibodies directly targeting the acetylcholine receptor (AChR) or other structural proteins of the neuromuscular junction. The majority of MG cases are associated with thymic pathologies, including thymoma, thyroiditis, autoimmune diseases or malignant hematologic neoplasia. The present study reported a rare case of AChR-positive and late-onset ocular MG, which rapidly progressed to a generalized myasthenic syndrome as an initial presentation of a pancreatic neuroendocrine neoplasia (pNEN). Following complete surgical resection of the pNEN, the myasthenic syndrome was improved and the anti-AChR antibody titers were reduced. It has been reported that MG is a paraneoplastic syndrome in thymic neoplasms and less common in hematologic malignancies. However, currently, only few cases of MG as initial presentation of a solid tumor, and more particular of a neuroendocrine neoplasm, have been reported in the literature. In conclusion, surveillance for extrathymic solid malignancies in newly diagnosed patients with MG could promote the early diagnosis of associated tumor diseases.

Long-term Outcome of Asymptomatic Patients With Graft Fibrosis in Protocol Biopsies After Pediatric Liver Transplantation

BACKGROUND

The histological prevalence of allograft fibrosis in asymptomatic children after liver transplantation (LT) is well documented. However, long-term graft and patient survival remain unclear. This retrospective multicenter study aims to determine the prevalence of allograft fibrosis and analyze the long-term outcome for patients transplanted in childhood.

METHODS

We reviewed clinical data of children who had undergone 10-y protocol liver biopsies. We excluded patients with autoimmune hepatitis, primary sclerosing cholangitis, hepatitis B or C, and retransplantation. In total, 494 patients transplanted in childhood across 12 international transplant centers were included. We evaluated the development of fibrosis by comparing the results with biopsies obtained 5 and 15 y post-LT. Histological findings were correlated with graft and patient survival up to 20 y post-LT.

RESULTS

In the 10-y biopsies, periportal or pericentral fibrosis was observed in 253 patients (51%), 87 (18%) had bridging fibrosis, 30 (6%) had cirrhosis, and 124 (25%) had no fibrosis. The prevalence and stage of graft fibrosis significantly progressed from 5 to 10 y. At 10 y, the severity of fibrosis correlated significantly with inflammation. Patients with graft cirrhosis in the 10-y biopsy were more likely to die or require retransplantation subsequently ( P = 0.027).

CONCLUSIONS

At 10 y post-LT, most patients transplanted in childhood developed fibrosis, based on the protocol liver biopsies. Although mild-to-moderate graft fibrosis did not largely affect patient or graft survival up to 20 y post-LT, this progressive fibrosis finding has substantial implications for developing cirrhosis and portal hypertension in adult care.

Deep Learning-Enabled Diagnosis of Liver Adenocarcinoma

BACKGROUND & AIMS

Diagnosis of adenocarcinoma in the liver is a frequent scenario in routine pathology and has a critical impact on clinical decision making. However, rendering a correct diagnosis can be challenging, and often requires the integration of clinical, radiologic, and immunohistochemical information. We present a deep learning model (HEPNET) to distinguish intrahepatic cholangiocarcinoma from colorectal liver metastasis, as the most frequent primary and secondary forms of liver adenocarcinoma, with clinical grade accuracy using H&E-stained whole-slide images.

METHODS

HEPNET was trained on 714,589 image tiles from 456 patients who were randomly selected in a stratified manner from a pool of 571 patients who underwent surgical resection or biopsy at Heidelberg University Hospital. Model performance was evaluated on a hold-out internal test set comprising 115 patients and externally validated on 159 patients recruited at Mainz University Hospital.

RESULTS

On the hold-out internal test set, HEPNET achieved an area under the receiver operating characteristic curve of 0.994 (95% CI, 0.989-1.000) and an accuracy of 96.522% (95% CI, 94.521%-98.694%) at the patient level. Validation on the external test set yielded an area under the receiver operating characteristic curve of 0.997 (95% CI, 0.995-1.000), corresponding to an accuracy of 98.113% (95% CI, 96.907%-100.000%). HEPNET surpassed the performance of 6 pathology experts with different levels of experience in a reader study of 50 patients (P = .0005), boosted the performance of resident pathologists to the level of senior pathologists, and reduced potential downstream analyses.

CONCLUSIONS

We provided a ready-to-use tool with clinical grade performance that may facilitate routine pathology by rendering a definitive diagnosis and guiding ancillary testing. The incorporation of HEPNET into pathology laboratories may optimize the diagnostic workflow, complemented by test-related labor and cost savings.

Diagnostic Approaches for Neuroendocrine Neoplasms of Unknown Primary (NEN-UPs) and Their Prognostic Relevance-A Retrospective, Long-Term Single-Center Experience

Neuroendocrine neoplasms (NENs) represent a rare and heterogenous group of tumors with predominantly gastroenteropancreatic or pulmonary origin. Despite numerous diagnostic efforts, the primary tumor site remains unknown in up to 20% of the patients diagnosed with NEN. In this subgroup of NEN patients, a standard diagnostic algorithm has not yet been integrated into clinical routine. Of note, an undetermined primary tumor site in NENs is associated with an impaired clinical outcome by at least "formally" limiting treatment options exclusively approved for NENs of a certain histological origin. In this retrospective study, a patient cohort of 113 patients initially diagnosed with NEN of unknown primary (NEN-UP) was analyzed. In 13 patients (11.5%) a primary tumor site could be identified subsequently, amongst others, by performing somatostatin receptor (SSTR)-PET-based imaging, which was irrespective of the initial clinical or demographic features. Diagnostic work-up and therapeutic regimens did not differ significantly between patients with an identified or unidentified primary tumor site; only a detailed immunohistochemical assessment providing additional information on the tumor origin proved to be significantly associated with the detection of a primary tumor site. Our study revealed that a profound diagnostic work-up, particularly including SSTR-PET-based imaging, leads to additional treatment options, finally resulting in significantly improved clinical outcomes for patients with NEN-UPs.

NOTCH3 missense mutations as predictor of long-term response to gemcitabine in a patient with epithelioid hemangioendothelioma

PURPOSE

Epithelioid hemangioendothelioma (EHE) as a very rare malignant vascular tumor belongs to the heterogenous group of soft-tissue sarcomas. Depending on the clinical course of the disease, interdisciplinary treatment concepts are required, including surgery, radiotherapy and systemic cancer therapy. However, due to its uncommonness, standard treatment options are lacking so far, especially in advanced disease with distant metastases.

METHODS AND RESULTS

Here we report on an unusual case of a patient with metastasized EHE showing long-term response to second line treatment with gemcitabine over almost 2 decades. Cancer genome sequencing of the patient's tumor tissue detected a NOTCH3 missense mutation which could provide an explanation for these clinical findings. NOTCH3 is known to be a mediator of resistance towards gemcitabine-based cancer treatment, at least in pancreatic cancer and non-small cell lung cancer.

CONCLUSION

The observation that this missense mutation of NOTCH3 is associated with an increased response to treatment with gemcitabine in EHE can be used prospectively to assess NOTCH3 as potential biomarker for predicting therapy response to gemcitabine.

Depression and anxiety in women with malignant ovarian germ cell (MOGCT) and sex cord stromal tumors (SCST): an analysis of the AGO-CORSETT database

INTRODUCTION

The intention of this study was to evaluate the level of anxiety and depression of malignant ovarian germ cell (MOGCT) and sex cord stromal tumors (SCST) survivors and to identify possible alterable cofactors.

METHODS

CORSETT was an observational, multicenter, mixed retrospective/prospective cohort study of the AGO Studygroup. Women who had been diagnosed with MOGCTs and SCSTs between 2001 and 2011 were asked to complete the Hospital Anxiety and Depression Scale (HADS) to evaluate distress. Predictors of distress (type of surgery, chemotherapy, time since diagnosis, recurrence, second tumor, pain) were investigated using multivariate linear regression analysis.

RESULTS

150 MOGCT and SCST patients with confirmed histological diagnosis completed the questionnaire median seven years after diagnosis. They had a HADS total score ≥ 13 indicating severe mental distress in 34% of cases. Patients after fertility-conserving surgery had lower probability of severe mental distress than those without fertility-conserving treatment (β = - 3.1, p = 0.04). Pain was associated with the level of distress in uni- and multivariate analysis (coef 0.1, p < 0.01, coef. Beta 0.5).

DISCUSSION

Severe mental distress was frequent in patients with MOGCT and SCST and the level of pain was associated with the level of distress. Fertility conserving therapy, however, was associated with less mental distress. Screening and treatment of pain and depression is required to improve mental well-being in survivors of MOGCT and SCST.

Clinical outcome of biomarker-guided therapies in adult patients with tumors of the nervous system

Background

The clinical utility of molecular profiling and targeted therapies for neuro-oncology patients outside of clinical trials is not established. We aimed at investigating feasibility and clinical utility of molecular profiling and targeted therapy in adult patients with advanced tumors in the nervous system within a prospective observational study.

Methods

molecular tumor board (MTB)@ZPM (NCT03503149) is a prospective observational precision medicine study for patients with advanced tumors. After inclusion of patients, we performed comprehensive molecular profiling, formulated ranked biomarker-guided therapy recommendations based on consensus by the MTB, and collected prospective clinical outcome data.

Results

Here, we present initial data of 661 adult patients with tumors of the nervous system enrolled by December 31, 2021. Of these, 408 patients were presented at the MTB. Molecular-instructed therapy recommendations could be made in 380/408 (93.1%) cases and were prioritized by evidence levels. Therapies were initiated in 86/380 (22.6%) cases until data cutoff. We observed a progression-free survival ratio >1.3 in 31.3% of patients.

Conclusions

Our study supports the clinical utility of biomarker-guided therapies for neuro-oncology patients and indicates clinical benefit in a subset of patients. Our data might inform future clinical trials, translational studies, and even clinical care.

LPA receptor 1 (LPAR1) is a novel interaction partner of Filamin A that promotes Filamin A phosphorylation, MRTF-A transcriptional activity and oncogene-induced senescence

Myocardin-related transcription factors A and B (MRTFs) are coactivators of Serum Response Factor (SRF), which controls fundamental biological processes such as cell growth, migration, and differentiation. MRTF and SRF transcriptional activity play an important role in hepatocellular carcinoma (HCC) growth, which represents the second leading cause of cancer-related mortality in humans worldwide. We, therefore, searched for druggable targets in HCC that regulate MRTF/SRF transcriptional activity and can be exploited therapeutically for HCC therapy. We identified the G protein-coupled lysophosphatidic acid receptor 1 (LPAR1) as a novel interaction partner of MRTF-A and Filamin A (FLNA) using fluorescence resonance energy transfer-(FRET) and proximity ligation assay (PLA) in vitro in HCC cells and in vivo in organoids. We found that LPAR1 promotes FLNA phosphorylation at S2152 which enhances the complex formation of FLNA and MRTF-A, actin polymerization, and MRTF transcriptional activity. Pharmacological blockade or depletion of LPAR1 prevents FLNA phosphorylation and complex formation with MRTF-A, resulting in reduced MRTF/SRF target gene expression and oncogene-induced senescence. Thus, inhibition of the LPAR1-FLNA-MRTF-A interaction represents a promising strategy for HCC therapy.

Immunophenotyping of Circulating and Intratumoral Myeloid and T Cells in Glioblastoma Patients

Glioblastoma is the most common and lethal primary brain malignancy that almost inevitably recurs as therapy-refractory cancer. While the success of immune checkpoint blockade (ICB) revealed the immense potential of immune-targeted therapies in several types of cancers outside the central nervous system, it failed to show objective responses in glioblastoma patients as of now. The ability of glioblastoma cells to drive multiple modes of T cell dysfunction while exhibiting low-quality neoepitopes, low-mutational load, and poor antigen priming limits anti-tumor immunity and efficacy of antigen-unspecific immunotherapies such as ICB. An in-depth understanding of the GBM immune landscape is essential to delineate and reprogram such immunosuppressive circuits during disease progression. In this view, the present study aimed to characterize the peripheral and intratumoral immune compartments of 35 glioblastoma patients compared to age- and sex-matched healthy control probands, particularly focusing on exhaustion signatures on myeloid and T cell subsets. Compared to healthy control participants, different immune signatures were already found in the peripheral circulation, partially related to the steroid medication the patients received. Intratumoral CD4+ and CD8+ TEM cells (CD62L^low/CD45RO^high) revealed a high expression of PD1, which was also increased on intratumoral, pro-tumorigenic macrophages/microglia. Histopathological analysis further identified high PSGL-1 expression levels of the latter, which has recently been linked to increased metastasis in melanoma and colon cancer via P-selectin-mediated platelet activation. Overall, the present study comprises immunophenotyping of a patient cohort to give implications for eligible immunotherapeutic targets in neurooncology in the future.

Spatiotemporal analysis of tumour-infiltrating immune cells in biliary carcinogenesis

BACKGROUND

Intraductal papillary neoplasms (IPN) and biliary epithelial neoplasia (BilIN) are well-defined precursor lesions of biliary tract carcinoma (BTC). The aim of this study was to provide a comprehensive characterisation of the inflammatory microenvironment in BTC precursor lesions.

METHODS

Immunohistochemistry was employed to assess tumour-infiltrating immune cells in tissue samples from patients, for whom precursor lesions were identified alongside invasive BTC. The spatiotemporal evolution of the immune microenvironment during IPN-associated carcinogenesis was comprehensively analysed using triplet sample sets of non-neoplastic epithelium, precursor lesion and invasive BTC. Immune-cell dynamics during IPN- and BilIN-associated carcinogenesis were subsequently compared.

RESULTS

Stromal CD3⁺ (P = 0.002), CD4⁺ (P = 0.007) and CD8⁺ (P < 0.001) T cells, CD20⁺ B cells (P = 0.008), MUM1⁺ plasma cells (P = 0.012) and CD163⁺ M2-like macrophages (P = 0.008) significantly decreased in IPN compared to non-tumorous biliary epithelium. Upon transition from IPN to invasive BTC, stromal CD68⁺ (P = 0.001) and CD163⁺ (P < 0.001) macrophages significantly increased. In contrast, BilIN-driven carcinogenesis was characterised by significant reduction of intraepithelial CD8⁺ T-lymphocytic infiltration from non-tumorous epithelium via BilIN (P = 0.008) to BTC (P = 0.004).

CONCLUSION

IPN and BilIN are immunologically distinct entities that undergo different immune-cell variations during biliary carcinogenesis. Intraepithelial CD8⁺ T-lymphocytic infiltration of biliary tissue decreased already at the IPN-precursor stage, whereas BilIN-associated carcinogenesis showed a slowly progressing reduction towards invasive carcinoma.

Case report: Immunovirotherapy as a novel add-on treatment in a patient with thoracic NUT carcinoma

NUT carcinoma (NC) is a rare and extremely aggressive form of cancer, usually presenting with intrathoracic or neck manifestations in adolescents and young adults. With no established standard therapy regimen and a median overall survival of only 6.5 months, there is a huge need for innovative treatment options. As NC is genetically driven by a single aberrant fusion oncoprotein, it is generally characterized by a low tumor mutational burden, thus making it immunologically cold and insusceptible to conventional immunotherapy. Recently, we have demonstrated that oncolytic viruses (OVs) are able to specifically infect and lyse NC cells, thereby turning an immunologically cold tumor microenvironment into a hot one. Here, we report an intensive multimodal treatment approach employing for the first time an OV (talimogene laherparepvec (T-VEC); IMLYGIC®) together with the immune checkpoint inhibitor pembrolizumab as an add-on to a basic NC therapy (cytostatic chemotherapy, radiation therapy, epigenetic therapy) in a patient suffering from a large thoracic NC tumor which exhibits an aberrant, unique BRD3:NUTM1 fusion. This case demonstrates for the first time the feasibility of this innovative add-on immunovirotherapy regimen with a profound, repetitive and durable replication of T-VEC that is instrumental in achieving tumor stabilization and improvement in the patient´s quality of life. Further, a previously unknown BRD3:NUTM1 fusion gene was discovered that lacks the extraterminal domain of BRD3.

Postoperative IL-6 levels cannot predict early onset periprosthetic hip/knee infections: an analysis of 7,661 patients at a single institution

Prior studies have outlined C-reactive protein (CRP) within the first 5 d following total hip arthroplasty (THA) as an inappropriate indicator of an early periprosthetic joint infection (PJI). Recently, interleukin-6 (IL-6), as a potential inflammatory marker following total joint arthroplasty (TJA), has gained increasing interest, particularly due to its considerably shorter half-life. The aim of the present study was to assess IL-6 measured on postoperative day 3 following TJA as a prediction marker of early onset PJI. 7,661 patients, who underwent total hip or knee arthroplasty (THA, TKA) at a single institution between 2016 and 2019, were evaluated. Serum IL-6 values were measured on postoperative day 3 and compared between patients, with and without early onset PJI in the postoperative follow-up, matched for age, gender, Surgical Site Infection Risk Score and Charlson comorbidity index. Overall (n = 7,661), there was no statistically significant difference in serum IL-6 levels comparing patients with and without early onset PJI following THA [38.9 pg/ mL vs. 32.0 pg/mL, p = 0.116] and TKA [30.6 pg/mL vs. 28.2 pg/mL, p = 0.718]. Male gender and high body mass index were associated with an increased risk of early onset PJI following THA (p = 0.027, p = 0.002). Matched cohort analysis (n = 86) showed no statistically significant difference in serum IL-6 levels between patients with and without early onset PJI following THA (p = 0.680) and TKA (p = 0.910). Serum IL-6 values on postoperative day 3 following THA or TKA could not predict early onset PJIs.

Beware of gastric tube in esophagectomy after gastric radiotherapy: A case report

BACKGROUND

Gastric tube formation and pull-up is the most common technique of reconstruction following esophagectomy for esophageal cancer. If previous treatment with radiotherapy for gastric mucosa-associated lymphoid tissue (MALT)-lymphoma restricts suitability of the stomach for anastomosis to the esophagus is unknown.

CASE SUMMARY

A 57-year-old man underwent sequential chemotherapy and radiotherapy for gastric MALT-lymphoma seven years prior to diagnosis of esophageal adenocarcinoma. Esophagectomy without neoadjuvant treatment was recommended by the multidisciplinary tumor board due to early tumor stage [uT1 (sm2) uN+ cM0 according to TNM-classification of malignant tumors, 8^th edition] without lymph node involvement. Minimal invasive esophageal resection with esophagogastrostomy was performed. Due to gastric tube necrosis with anastomotic leakage on the twelfth postoperative day, diverting resection with construction of a cervical salivary fistula was necessary. Rapid recovery facilitated colonic interposition without any complications six months afterwards.

CONCLUSION

This case report may represent the start for further investigation to know if it is reasonable to refrain from esophagogastrostomy in patients with a long interval between gastric radiotherapy and surgery.

Abstract CT178: A phase 1/2, open-label study to assess safety, tolerability, biodistribution, radiation dosimetry and PET imaging characteristics of [18F]FPyGal in comparison to in-vitro diagnostic for the assessment of senescence in oncological patients

The authors did not submit an updated abstract. The original abstract should be considered final.

Citation Format: Christian LaFougere, Brigitte Gueckel, Helmut Dittmann, Martina Hinterleitner, Nils Trautwein, Jonathan Cotton, Gabriele Kienzle, Stephan Singer, Gerald Reischl, Ulrich Lauer, Bernd Pichler, Lars Zender. A phase 1/2, open-label study to assess safety, tolerability, biodistribution, radiation dosimetry and PET imaging characteristics of [18F]FPyGal in comparison to in-vitro diagnostic for the assessment of senescence in oncological patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT178.

ATRT-19. Functional genomics reveal distinct modulators of response to CDK4/6 inhibitors in ATRTs

Brain tumors are the leading cause of cancer-related deaths in children, and atypical teratoid rhabdoid tumors (ATRTs) are among the most common aggressive brain tumors in infants. With no standard-of-care treatment so far, ATRTs continue to have relatively low survival estimates, illustrating the urgent need for more efficacious treatment options. We have previously used genome-wide CRISPR/Cas9 knockout screens in combination with small-molecule drug assays to identify targetable vulnerabilities in ATRTs. CDK4/6 inhibitors, among the most promising drugs in our study with direct translational potential, are capable of inhibiting tumor growth due to mutual exclusive dependency of ATRTs on either CDK4 or CDK6. We here used genome-wide loss-of-function and gain-of-function strategies to identify modulators of response to CDK4/6 inhibition in ATRTs. Of note, while some well-known resistance mechanisms such as loss of RB1 or FBXW7 are shared by ATRT cell lines, we have also identified modulators of response to CDK4/6 inhibition with opposing effects across ATRT cell lines. As such, loss of AMBRA1, a recently described master regulator of D type cyclins, can either oppose the effects of or synergize with CDK4/6 inhibitors based on the cellular background. We are currently using a proteomics approach to further delineate the mechanism driving this functional heterogeneity of AMBRA1 in ATRTs. Our study will therefore provide deeper insights into the response of ATRTs to CDK4/6 inhibitors, which represent one of the most promising class of targeted agents for the treatment of ATRTs.

[Sun protection of human skin: from A to Z]

Solar radiation contains about 6.8% ultraviolet (UV) radiation. UV radiation is still regarded as one of the most important risk factors for both nonmelanoma skin cancer (NMSC; predominantly basal cell carcinoma and squamous cell carcinoma) and malignant melanoma (MM). To avoid induction and persistence of UV-induced mutations, our skin is armed with an arsenal of endogenous protective mechanisms such as induction of cell cycle arrest, repair mechanisms, immunosurveillance and the initiation of various types of cell death. Exogenous sun protection includes a range of behaviors such as avoiding extensive sun exposure, wearing UV-proof clothing and appropriate application of topical sunscreens.

Metabolic implications of pancreatic fat accumulation

Fat accumulation outside subcutaneous adipose tissue often has unfavourable effects on systemic metabolism. In addition to non-alcoholic fatty liver disease, which has received considerable attention, pancreatic fat has become an important area of research throughout the past 10 years. While a number of diagnostic approaches are available to quantify pancreatic fat, multi-echo Dixon MRI is currently the most developed method. Initial studies have shown associations between pancreatic fat and the metabolic syndrome, impaired glucose metabolism and type 2 diabetes mellitus. Pancreatic fat is linked to reduced insulin secretion, at least under specific circumstances such as prediabetes, low BMI and increased genetic risk of type 2 diabetes mellitus. This Review summarizes the possible causes and metabolic consequences of pancreatic fat accumulation. In addition, potential therapeutic approaches for addressing pancreatic fat accumulation are discussed.

The Transmembrane Receptor TIRC7 Identifies a Distinct Subset of Immune Cells with Prognostic Implications in Cholangiocarcinoma

Cholangiocarcinoma (CCA) is a heterogeneous malignancy with a dismal prognosis. Therapeutic options are largely limited to surgery and conventional chemotherapy offers limited benefit. As immunotherapy has proven highly effective in various cancer types, we have undertaken a quantitative immunohistopathological assessment of immune cells expressing the immunoinhibitory T cell immune response cDNA 7 receptor (TIRC7), an emerging immunoinhibitory receptor, in a cohort of 135 CCA patients. TIRC7+ immune cells were present in both the tumor epithelia and stroma in the majority of CCA cases with the highest levels found in intrahepatic CCA. While intraepithelial density of TIRC7+ immune cells was decreased compared to matched non-neoplastic bile ducts, stromal quantity was higher in the tumor samples. Tumors exhibiting signet ring cell or adenosquamous morphology were exclusively associated with an intraepithelial TIRC7+ phenotype. Survival analysis showed intraepithelial TIRC7+ immune cell density to be a highly significant favorable prognosticator in intrahepatic but not proximal or distal CCA. Furthermore, intraepithelial TIRC7+ immune cell density correlated with the number of intraepithelial CD8+ immune cells and with the total number of CD4+ immune cells. Our results suggest the presence and prognostic relevance of TIRC7+ immune cells in CCA and warrant further functional studies on its pharmacological modulation.

EXTH-69. FUNCTIONAL GENOMICS UNCOVER GENETIC DEPENDENCIES IN ATRTS

Brain tumors are the leading cause of cancer-related deaths in children. Embryonal brain tumors including medulloblastoma and atypical teratoid rhabdoid tumors (ATRTs) account for 15% of all primary brain and CNS tumors under the age of 14 years, with ATRTs being most prevalent in infants. Despite intensive research efforts, survival estimates for ATRT patients stay relatively low as compared to other tumor entities with a median survival of around 17 months. We here describe genome-wide CRISPR/Cas9 knockout screens in combination with small-molecule drug assays to identify targetable vulnerabilities in ATRTs. Based on functional genomic screening revealing ATRT context-specific genetic vulnerabilities (n = 671 genes), we successfully generated a small-molecule library that shows preferential activity in ATRT cells as compared to a broad selection of other human cancer cell lines. Of note, none of these drugs differentially affect ATRT cells from distinct molecular subgroups, suggesting that top candidate inhibitors might serve as pan-ATRT therapeutic avenues. CDK4/6 inhibitors, among the most potent drugs in our library, are capable of inhibiting tumor growth due to mutual exclusive dependency of ATRTs on either CDK4 or CDK6. Our approach might serve as a blueprint for fostering the identification of functionally-instructed therapeutic strategies in other incurable diseases beyond ATRT, whose genomic profiles also lack actionable alterations so far.

Tetraspanin 5 (TSPAN5), a Novel Gatekeeper of the Tumor Suppressor DLC1 and Myocardin-Related Transcription Factors (MRTFs), Controls HCC Growth and Senescence

Simple Summary

Hepatocellular carcinoma (HCC) ranks second among the leading causes of cancer-related death. Since current therapeutic options are very limited, a deeper understanding of the molecular mechanisms underlying the tumor onset and progression of HCC holds great potential for improved therapeutic options. Although it has been shown that deleted in liver cancer 1 (DLC1) acts as a tumor suppressor whose allele is lost in 50% of liver cancers, alterations in gene expression initiated by DLC1 loss have not yet been the primary focus of liver cancer research. To identify novel gene targets that allow for a personalized medicine approach for HCC therapy, we performed gene expression profiling for HepG2 cells stably expressing DLC1shRNA. We provide evidence that TSPAN5 is required for HCC growth, migration and invasion, and dissected the underlying molecular mechanisms involving myocardin-related transcription factors. Thus, TSPAN5 represents a novel therapeutic target for the treatment of HCC characterized by DLC1 loss.

Abstract

Human hepatocellular carcinoma (HCC) is among the most lethal and common cancers in the human population, and new molecular targets for therapeutic intervention are urgently needed. Deleted in liver cancer 1 (DLC1) was originally identified as a tumor suppressor gene in human HCC. DLC1 is a Rho-GTPase-activating protein (RhoGAP) which accelerates the return of RhoGTPases to an inactive state. We recently described that the restoration of DLC1 expression induces cellular senescence. However, this principle is not amenable to direct therapeutic targeting. We therefore performed gene expression profiling for HepG2 cells depleted of DLC1 to identify druggable gene targets mediating the effects of DLC1 on senescence induction. This approach revealed that versican (VCAN), tetraspanin 5 (TSPAN5) and N-cadherin (CDH2) were strongly upregulated upon DLC1 depletion in HCC cells, but only TSPAN5 affected the proliferation of HCC cells and human HCC. The depletion of TSPAN5 induced oncogene-induced senescence (OIS), mediated by the p16^INK4a/pRb pathways. Mechanistically, silencing TSPAN5 reduced actin polymerization and thereby myocardin-related transcription factor A- filamin A (MRTF-A-FLNA) complex formation, resulting in decreased expression of MRTF/SRF-dependent target genes and senescence induction in vitro and in vivo. Our results identify TSPAN5 as a novel druggable target for HCC.

Hormonally Induced Hepatocellular Carcinoma in Diabetic Wild Type and Carbohydrate Responsive Element Binding Protein Knockout Mice

OBJECTIVE

In the rat, the pancreatic islet transplantation model is an established method to induce hepatocellular carcinomas (HCC), due to insulin-mediated metabolic and molecular alterations like increased glycolysis and de novo lipogenesis and the oncogenic AKT/mTOR pathway including upregulation of the transcription factor Carbohydrate-response element-binding protein (ChREBP). ChREBP could therefore represent an essential oncogenic co-factor during hormonally induced hepatocarcinogenesis.

METHODS

Pancreatic islet transplantation was implemented in diabetic C57Bl/6J (wild type, WT) and ChREBP-knockout (KO) mice for 6 and 12 months. Liver tissue was examined using histology, immunohistochemistry, electron microscopy and Western blot analysis. Finally, we performed NGS-based transcriptome analysis between WT and KO liver tumor tissues.

RESULTS

Three hepatocellular carcinomas were detectable after 6 and 12 months in diabetic transplanted WT mice, but only one in a KO mouse after 12 months. Pre-neoplastic clear cell foci (CCF) were also present in liver acini downstream of the islets in WT and KO mice. In KO tumors, glycolysis, de novo lipogenesis and AKT/mTOR signalling were strongly downregulated compared to WT lesions. Extrafocal liver tissue of diabetic, transplanted KO mice revealed less glycogen storage and proliferative activity than WT mice. From transcriptome analysis, we identified a set of transcripts pertaining to metabolic, oncogenic and immunogenic pathways that are differentially expressed between tumors of WT and KO mice. Of 315 metabolism-associated genes, we observed 199 genes that displayed upregulation in the tumor of WT mice, whereas 116 transcripts showed their downregulated expression in KO mice tumor.

CONCLUSIONS

The pancreatic islet transplantation model is a suitable method to study hormonally induced hepatocarcinogenesis also in mice, allowing combination with gene knockout models. Our data indicate that deletion of ChREBP delays insulin-induced hepatocarcinogenesis, suggesting a combined oncogenic and lipogenic function of ChREBP along AKT/mTOR-mediated proliferation of hepatocytes and induction of hepatocellular carcinoma.

Targeting extracellular and juxtamembrane FGFR2 mutations in chemotherapy-refractory cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) has emerged as a promising candidate for precision medicine, especially in the case of activating FGFR2 gene fusions. In addition to fusions, a considerable fraction of iCCA patients reveals FGFR2 mutations, which might lead to uncontrolled activation of the FGFR2 pathway but are mostly of unknown functional significance. A current challenge for molecular tumor boards (MTB) is to predict the functional consequences of such FGFR2 alterations to guide potential treatment decisions. We report two iCCA patients with extracellular and juxtamembrane FGFR2 mutations. After in silico investigation of the alterations and identification of activated FGFR2 downstream targets in tumor specimens by immunohistochemistry and transcriptome analysis, the MTB recommended treatment with an FGFR-inhibiting tyrosine kinase inhibitor. Both patients developed a rapidly detectable and prolonged partial response to treatment. These two cases suggest an approach to characterize further detected FGFR2 mutations in iCCA to enable patients´ selection for a successful application of the FGFR -inhibiting drugs.

Sonographic findings in coronavirus disease-19 associated liver damage

Purpose

This study was conducted to evaluate the role of liver sonography in patients with coronavirus disease 2019 (COVID-19) and elevated liver enzymes.

Materials and methods

In this retrospective study, patients tested positive for SARS-CoV-2 in our emergency ward between January 01 and April 24, 2020 and elevated liver enzymes were included (Cohort 1). Additionally, the local radiology information system was screened for sonographies in COVID-19 patients at the intensive care unit in the same period (Cohort 2). Liver sonographies and histologic specimen were reviewed and suspicious findings recorded. Medical records were reviewed for clinical data. Ultrasound findings and clinical data were correlated with severity of liver enzyme elevation.

Results

Cohort 1: 126 patients were evaluated, of which 47 (37.3%) had elevated liver enzymes. Severity of liver enzyme elevation was associated with death (p<0.001). 8 patients (6.3%) had suspicious ultrasound findings, including signs of acute hepatitis (n = 5, e.g. thickening of gall bladder wall, hepatomegaly, decreased echogenicity of liver parenchyma) and vascular complications (n = 4). Cohort 2: 39 patients were evaluated, of which 14 are also included in Cohort 1. 19 patients (48.7%) had suspicious ultrasound findings, of which 13 patients had signs of acute hepatitis and 6 had vascular complications. Pathology was performed in 6 patients. Predominant findings were severe cholestasis and macrophage activation.

Conclusion

For most hospitalized COVID-19 patients, elevated liver enzymes cause little concern as they are only mild to moderate. However, in severely ill patients bedside sonography is a powerful tool to reveal different patterns of vascular, cholestatic or inflammatory complications in the liver, which are associated with high mortality. In addition, macrophage activation as histopathologic correlate for a hyperinflammatory syndrome seems to be a frequent complication in COVID-19.

To which extent do breast cancer survivors feel well informed about disease and treatment 5 years after diagnosis?

OBJECTIVE

In this study, we investigated to which extent patients feel well informed about their disease and treatment, which areas they wish more or less information and which variables are associated with a need for information about the disease, medical tests and treatment.

METHODS

In a German multi-centre prospective study, we enrolled 759 female breast cancer patients at the time of cancer diagnosis (baseline). Data on information were captured at 5 years after diagnosis with the European Organisation for Research and Treatment of Cancer (EORTC) Information Module (EORTC QLQ-INFO24). Good information predictors were analysed using linear regression models.

RESULTS

There were 456 patients who participated at the 5-year follow-up. They reported to feel well informed about medical tests (mean score 78.5) and the disease itself (69.3) but relatively poorly about other services (44.3) and about different places of care (31.3). The survivors expressed a need for more information concerning: side effects and long-term consequences of therapy, more information in general, information about aftercare, prognosis, complementary medicine, disease and therapy. Patients with higher incomes were better informed about medical tests (β 0.26, p 0.04) and worse informed with increasing levels of fear of treatment (β - 0.11, p 0.02). Information about treatment was reported to be worse by survivors > 70 years old (β -0.34, p 0.03) and by immigrants (β -0.11, p 0.02). Survivors who had received additional written information felt better informed about disease, medical tests, treatment and other services (β 0.19/0.19/0.20/0.25; each p < 0.01).

CONCLUSION

Health care providers have to reconsider how and what kind of information they provide. Providing written information, in addition to oral information, may improve meeting those information needs.

Children and adolescents' neural response to emotional faces and voices: Age-related changes in common regions of activation

The perception of facial and vocal emotional expressions engages overlapping regions of the brain. However, at a behavioral level, the ability to recognize the intended emotion in both types of nonverbal cues follows a divergent developmental trajectory throughout childhood and adolescence. The current study a) identified regions of common neural activation to facial and vocal stimuli in 8- to 19-year-old typically-developing adolescents, and b) examined age-related changes in blood-oxygen-level dependent (BOLD) response within these areas. Both modalities elicited activation in an overlapping network of subcortical regions (insula, thalamus, dorsal striatum), visual-motor association areas, prefrontal regions (inferior frontal cortex, dorsomedial prefrontal cortex), and the right superior temporal gyrus. Within these regions, increased age was associated with greater frontal activation to voices, but not faces. Results suggest that processing facial and vocal stimuli elicits activation in common areas of the brain in adolescents, but that age-related changes in response within these regions may vary by modality.

Spatially resolved analysis of FFPE tissue proteomes by quantitative mass spectrometry

Bottom-up mass spectrometry-based proteomics relies on protein digestion and peptide purification. The application of such methods to broadly available clinical samples such as formalin-fixed and paraffin-embedded (FFPE) tissues requires reversal of chemical crosslinking and the removal of reagents that are incompatible with mass spectrometry. Here, we describe in detail a protocol that combines tissue disruption by ultrasonication, heat-induced antigen retrieval and two alternative methods for efficient detergent removal to enable quantitative proteomic analysis of limited amounts of FFPE material. To show the applicability of our approach, we used hepatocellular carcinoma (HCC) as a model system. By combining the described protocol with laser-capture microdissection, we were able to quantify the intra-tumor heterogeneity of a tumor specimen on the proteome level using a single slide with tissue of 10-µm thickness. We also demonstrate broader applicability to other tissues, including human gallbladder and heart. The procedure described in this protocol can be completed within 8 d.

The effects of incidental findings from whole-body MRI on the frequency of biopsies and detected malignancies or benign conditions in a general population cohort study

Magnetic resonance imaging (MRI) yields numerous tumor-related incidental findings (IFs) which may trigger diagnostics such as biopsies. To clarify these effects, we studied how whole-body MRI IF disclosure in a population-based cohort affected biopsy frequency and the detection of malignancies. Laboratory disclosures were also assessed. Data from 6753 participants in the Study of Health in Pomerania (SHIP) examined between 2008 and 2012 were utilized. All underwent laboratory examinations and 3371 (49.9%) a whole-body MRI. Electronic biopsy reports from 2002 to 2017 were linked to participants and assigned to outcome categories. Biopsy frequency 2 years pre- and post-SHIP was investigated using generalized estimating equations with a negative-binomial distribution. Overall 8208 IFs (laboratory findings outside reference limits: 6839; MRI: 1369) were disclosed to 4707 participants; 2271 biopsy reports belonged to 1200 participants (17.8%). Of these, 938 biopsies occurred pre-SHIP; 1333 post-SHIP (event rate/100 observation years = 6.9 [95% CI 6.5; 7.4]; 9.9 [9.3; 10.4]). Age, cancer history, recent hospitalization, female sex, and IF disclosure were associated with higher biopsy rates. Nonmalignant biopsy results increased more in participants with disclosures (post-/pre-SHIP rate ratio 1.39 [95% CI 1.22; 1.58]) than without (1.09 [95% CI 0.85; 1.38]). Malignant biopsy results were more frequent post-SHIP (rate ratio 1.74 [95% CI 1.27; 2.42]). Biopsies increased after participation in a population-based cohort study with MRI and laboratory IF disclosure. Most biopsies resulted in no findings and few malignancies were diagnosed, indicating potential overtesting and overdiagnosis. A more restrictive policy regarding IF disclosure from research findings is required.

NOTCH target gene HES5 mediates oncogenic and tumor suppressive functions in hepatocarcinogenesis

NOTCH receptor signaling plays a pivotal role in liver homeostasis and hepatocarcinogenesis. However, the role of NOTCH pathway mutations and the NOTCH target gene HES5 in liver tumorigenesis are poorly understood. Here we performed whole-exome sequencing of 54 human HCC specimens and compared the prevalence of NOTCH pathway component mutations with the TCGA-LIHC cohort (N = 364). In addition, we functionally characterized the NOTCH target HES5 and the patient-derived HES5-R31G mutation in vitro and in an orthotopic mouse model applying different oncogenic backgrounds, to dissect the role of HES5 in different tumor subgroups in vivo. We identified nonsynonymous mutations in 14 immediate NOTCH pathway genes affecting 24.1% and 16.8% of HCC patients in the two independent cohorts, respectively. Among these, the HES5-R31G mutation was predicted in silico to have high biological relevance. Functional analyses in cell culture showed that HES5 reduced cell migration and clonogenicity. Further analyses revealed that the patient-derived HES5-R31G mutant protein was non-functional due to loss of DNA binding and greatly reduced nuclear localization. Furthermore, HES5 exhibited a negative feedback loop by directly inhibiting the NOTCH target HES1 and downregulated the pro-proliferative MYC targets ODC1 and LDHA. Interestingly, HES5 inhibited MYC-dependent hepatocarcinogenesis, whereas it promoted AKT-dependent liver tumor formation and stem cell features in a murine model. Thus, NOTCH pathway component mutations are commonly observed in HCC. Furthermore, the NOTCH target gene HES5 has both pro- and anti-tumorigenic functions in liver cancer proposing a driver gene dependency and it promotes tumorigenesis with its interaction partner AKT.

HER2 gene (ERBB2) amplification is a low-frequency driver with potential predictive value in gallbladder carcinoma

Gallbladder carcinoma (GBC) is an aggressive type of cancer with a dismal prognosis. Recent case reports have highlighted the human epidermal growth factor receptor 2 (HER2) as a promising target for individualized therapy in biliary tract cancer; however, current data on HER2 positivity in GBC is contradictory. This study aimed to assess the proportion of HER2 positivity and its clinical implications in a large and well-characterized European GBC cohort. HER2 status was determined in 186 cases of surgically resected gallbladder adenocarcinoma and a subset of coexistent high-grade biliary intraepithelial neoplasia (BilIN, n = 74) in accordance with the up-to-date consensus for HER2 testing in gastric cancer by immunohistochemistry and dual-color chromogenic in situ hybridization. Positivity for HER2 was observed in 5.4% of all cases (n = 10). In those patients with concomitant high-grade BilIN, two of four positive samples also showed amplification in the precursor lesion, while in the two remaining cases, positivity was either confined to invasive tumor or high-grade BilIN, exclusively. Equivocal staining found in eleven cases was not accompanied by gene amplification. Staging of the HER2-positive group was significantly different from the HER2-negative group with most cases presenting at stage IV, paralleled by a trend towards decreased survival. One patient who received dual HER2 inhibition almost went into full clinical remission despite treatment initiation in a metastasized state. Our results reveal a low prevalence of HER2 positivity and highlight HER2 gene amplification as an early, potentially driving event in gallbladder carcinogenesis. Prospective standardized HER2 testing and randomized control studies are needed to prove clinical efficacy of targeted HER2 inhibition in GBC.

Karyopherin α2-dependent import of E2F1 and TFDP1 maintains protumorigenic stathmin expression in liver cancer

Background

Members of the karyopherin superfamily serve as nuclear transport receptors/adaptor proteins and provide exchange of macromolecules between the nucleo- and cytoplasm. Emerging evidence suggests a subset of karyopherins to be dysregulated in hepatocarcinogenesis including karyopherin-α2 (KPNA2). However, the functional and regulatory role of KPNA2 in liver cancer remains incompletely understood.

Methods

Quantitative proteomics (LC-MS/MS, ~ 1750 proteins in total) was used to study changes in global protein abundance upon siRNA-mediated KPNA2 knockdown in HCC cells. Functional and mechanistic analyses included colony formation and 2D migration assays, co-immunoprecipitation (CoIP), chromatin immunoprecipitation (ChIP), qRT-PCR, immmunblotting, and subcellular fractionation. In vitro results were correlated with data derived from a murine HCC model and HCC patient samples (3 cohorts, n > 600 in total).

Results

The proteomic approach revealed the pro-tumorigenic, microtubule (MT) interacting protein stathmin (STMN1) among the most downregulated proteins upon KPNA2 depletion in HCC cells. We further observed that KPNA2 knockdown leads to reduced tumor cell migration and colony formation of HCC cells, which could be phenocopied by direct knockdown of stathmin. As the underlying regulatory mechanism, we uncovered E2F1 and TFDP1 as transport substrates of KPNA2 being retained in the cytoplasm upon KPNA2 ablation, thereby resulting in reduced STMN1 expression. Finally, murine and human HCC data indicate significant correlations of STMN1 expression with E2F1/TFPD1 and with KPNA2 expression and their association with poor prognosis in HCC patients.

Conclusion

Our data suggest that KPNA2 regulates STMN1 by import of E2F1/TFDP1 and thereby provide a novel link between nuclear transport and MT-interacting proteins in HCC with functional and prognostic significance.

Low frequency of mismatch repair deficiency in gallbladder cancer

Background

DNA mismatch repair (MMR) deficiency is a major pathway of genomic instability in cancer. It leads to the accumulation of numerous mutations predominantly at microsatellite sequences, a phenotype known as microsatellite instability (MSI). MSI tumors have a distinct clinical behavior and commonly respond well to immune checkpoint blockade, irrespective of their origin. Data about the prevalence of MSI among gallbladder cancer (GBC) have been conflicting. We here analyzed a well-characterized cohort of 69 Western-world GBCs.

Methods

We analyzed the mononucleotide MSI marker panel consisting of BAT25, BAT26, and CAT25 to determine the prevalence of MMR deficiency-induced MSI.

Results

MSI was detected in 1/69 (1.4%) of analyzed GBCs. The detected MSI GBC had a classical histomorphology, i.e. of acinar/tubular/glandular pancreatobiliary phenotype, and showed nuclear expression of all four MMR proteins MLH1, MSH2, MSH6, and PMS2. The MSI GBC patient showed a prolonged overall survival, despite having a high tumor stage at diagnosis. The patient had no known background or family history indicative of Lynch syndrome.

Conclusions

Even though the overall number of MSI tumors is low in GBC, the potentially therapeutic benefit of checkpoint blockade in the respective patients may justify MSI analysis of GBC.

Electronic supplementary material

The online version of this article (10.1186/s13000-019-0813-5) contains supplementary material, which is available to authorized users.

Integrative Analysis Defines Distinct Prognostic Subgroups of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (iCCA) is the second most common primary liver cancer. It is defined by cholangiocytic differentiation and has poor prognosis. Recently, epigenetic processes have been shown to play an important role in cholangiocarcinogenesis. We performed an integrative analysis on 52 iCCAs using both genetic and epigenetic data with a specific focus on DNA methylation components. We found recurrent isocitrate dehydrogenase 1 (IDH1) and IDH2 (28%) gene mutations, recurrent arm-length copy number alterations (CNAs), and focal alterations such as deletion of 3p21 or amplification of 12q15, which affect BRCA1 Associated Protein 1, polybromo 1, and mouse double minute 2 homolog. DNA methylome analysis revealed excessive hypermethylation of iCCA, affecting primarily the bivalent genomic regions marked with both active and repressive histone modifications. Integrative clustering of genetic and epigenetic data identified four iCCA subgroups with prognostic relevance further designated as IDH, high (H), medium (M), and low (L) alteration groups. The IDH group consisted of all samples with IDH1 or IDH2 mutations and showed, together with the H group, a highly disrupted genome, characterized by frequent deletions of chromosome arms 3p and 6q. Both groups showed excessive hypermethylation with distinct patterns. The M group showed intermediate characteristics regarding both genetic and epigenetic marks, whereas the L group exhibited few methylation changes and mutations and a lack of CNAs. Methylation-based latent component analysis of cell-type composition identified differences among these four groups. Prognosis of the H and M groups was significantly worse than that of the L group. Conclusion: Using an integrative genomic and epigenomic analysis approach, we identified four major iCCA subgroups with widespread genomic and epigenomic differences and prognostic implications. Furthermore, our data suggest differences in the cell-of-origin of the iCCA subtypes.

RIPK1 and death receptor signaling drive biliary damage and early liver tumorigenesis in mice with chronic hepatobiliary injury

Hepatocyte apoptosis is intrinsically linked to chronic liver disease and hepatocarcinogenesis. Conversely, necroptosis of hepatocytes and other liver cell types and its relevance for liver disease is debated. Using liver parenchymal cell (LPC)-specific TGF-beta-activated kinase 1 (TAK1)-deficient (TAK1^LPC-KO) mice, which exhibit spontaneous hepatocellular and biliary damage, hepatitis, and early hepatocarcinogenesis, we have investigated the contribution of apoptosis and necroptosis in hepatocyte and cholangiocyte death and their impact on liver disease progression. Here, we provide in vivo evidence showing that TAK1-deficient cholangiocytes undergo spontaneous necroptosis induced primarily by TNFR1 and dependent on RIPK1 kinase activity, RIPK3, and NEMO. In contrast, TAK1-deficient hepatocytes die by FADD-dependent apoptosis, which is not significantly inhibited by LPC-specific RIPK1 deficiency, inhibition of RIPK1 kinase activity, RIPK3 deficiency or combined LPC-specific deletion of TNFR1, TRAILR, and Fas. Accordingly, normal mouse cholangiocytes can undergo necroptosis, while primary hepatocytes are resistant to it and die exclusively by apoptosis upon treatment with cell death-inducing stimuli in vitro, likely due to the differential expression of RIPK3. Interestingly, the genetic modifications that conferred protection from biliary damage also prevented the spontaneous lethality that was often observed in TAK1^LPC-KO mice. In the presence of chronic hepatocyte apoptosis, preventing biliary damage delayed but did not avert hepatocarcinogenesis. On the contrary, inhibition of hepatocyte apoptosis fully prevented liver tumorigenesis even in mice with extensive biliary damage. Altogether, our results suggest that using RIPK1 kinase activity inhibitors could be therapeutically useful for cholestatic liver disease patients.

YAP-dependent induction of UHMK1 supports nuclear enrichment of the oncogene MYBL2 and proliferation in liver cancer cells

The oncogene yes-associated protein (YAP) is a key modifier of liver homeostasis and regulates mitosis in hepatocytes as well as in malignantly transformed cells. However, the question of how YAP supports cell proliferation in hepatocellular carcinoma (HCC) is not well understood. Here we identified U2AF momology motif kinase 1 (UHMK1) as a direct transcriptional target of YAP and the transcription factor forkhead box M1 (FOXM1), which supports HCC cell proliferation but not migration. Indeed, UHMK1 stimulates the expression of genes that are specific for cell cycle regulation and which are known downstream effectors of YAP. By using BioID labeling and mass spectrometry, the dimerization partner, RB-like, E2F and multi-vulval class B (DREAM) complex constituent MYB proto-oncogene like 2 (MYBL2, B-MYB) was identified as a direct UHMK1 interaction partner. Like YAP, UHMK1 stimulates nuclear enrichment of MYBL2, which is associated HCC cell proliferation and the expression of the cell cycle regulators CCNB1, CCNB2, KIF20A, and MAD2L1. The association between YAP, UHMK1, MYBL2, and proliferation was confirmed in YAP^S127A-transgenic mice and human HCC tissues. In summary, we provide a model by which YAP supports cell proliferation through the induction of important cell cycle regulators in a UHMK1- and MYBL2-dependent manner.

Prognostic Impact of Carboxylesterase 2 in Cholangiocarcinoma

Carboxylesterase 2 (CES2) is instrumental for conversion of ester-containing prodrugs in cancer treatment. Novel treatment strategies are exceedingly needed for cholangiocarcinoma (CCA) patients. Here, we assessed CES2 expression by immunohistochemistry in a CCA cohort comprising 171 non-liver fluke associated, intrahepatic (n = 72) and extrahepatic (perihilar: n = 56; distal: n = 43) CCAs. Additionally, 80 samples of high-grade biliary intraepithelial neoplastic tissues and 158 corresponding samples of histological normal, non-neoplastic biliary tract tissues were included. CES2 expression was highest in non-neoplastic biliary tissue and significantly decreased in CCA. Patients showing any CES2 expression in tumor cells had a significantly better overall survival compared to negative cases (p = 0.008). This survival benefit was also maintained after stratification of CES2-positive cases, by comparing low, medium and high CES2 expression levels (p-trend = 0.0006). Evaluation of CCA subtypes showed the survival difference to be restricted to extrahepatic tumors. Correlation of CES2 expression with data of tumor-infiltrating immune cells showed that particularly CD8+ T cells were more frequently detected in CES2-positive CCAs. Furthermore, treatment of CCA cell lines with the prodrug Irinotecan reduced cell viability, increased cytotoxicity and modulated inflammatory gene expression. In conclusion, reduced CES2 expression is associated with poor outcome and low CD8+ T cell infiltration in CCA patients. Further clinical studies could show, whether CES2 expression may serve as a predictive marker in patients treated with prodrugs converted by CES2.

Programmed cell death ligand 1 (PD-L1, CD274) in cholangiocarcinoma - correlation with clinicopathological data and comparison of antibodies

BACKGROUND

Cholangiocarcinoma (CCA) may arise in the intra- or extrahepatic biliary tract and is associated with a poor prognosis. Despite recent advances, to date there is still no established targeted therapeutic approach available. Non-surgical therapeutic agents are urgently needed, as most patients are non-eligible to surgical resection. Anti-PD-L1 therapy prevents cancer cells from evading the immune system and has emerged as a new treatment option in several cancer entities. Recently, PD-L1 expression has been analyzed in comparably small CCA patient cohorts. However, a systematic validation of different PD-L1 antibodies has not been performed in CCA so far.

METHODS

We stained a tissue microarray consisting of 170 patients, including 72 intrahepatic cholangiocarcinomas (iCCAs), 57 perihilar cholangiocarcinomas (pCCAs) and 41 distal cholangiocarcinomas (dCCAs) by immunohistochemistry and evaluated PD-L1 positivity in tumor and stromal cells. We analyzed three different PD-L1 antibodies (clones 28-8, SP142, and SP263) that are frequently used and recommended for predictive diagnostic testing in other cancer types.

RESULTS

For PD-L1 antibody clone SP263, 5% of iCCAs, 4% of pCCAs and 3% of dCCAs exhibited PD-L1 expression on tumor cells, thereby showing the highest frequencies of PD-L1 positivity. Accordingly, highest PD-L1 positivity rates of stromal cells with 31% in iCCA, 40% in pCCA and 61% in dCCA were detected for clone SP263. Agreement of PD-L1 positivity in tumor cells was moderate for clone 28-8 and SP263 (κ = 0.44) and poor between 28-8 and SP142 (κ = 0.13), as well as  SP142 and SP263 (κ = 0.11), respectively. Statistical analyses of PD-L1 expression (clone SP263) on tumor cells with clinicopathological data revealed a positive correlation with shortened overall survival in CCA patients.

CONCLUSIONS

Selection of appropriate PD-L1 antibodies and careful evaluation of immunohistochemical staining patterns have a significant impact on PD-L1 testing in CCA. Clinical trials are necessary to investigate the putative beneficial effects of PD-L1 targeted immunotherapy in CCA patients.