Exceptional Response of BRAFV600E-Mutated Acinar Cell CUP to BRAF/MEK Inhibition.

Complete remission of BRAF V600E-driven ACC CUP by BRAF/MEK inhibition underscores importance of precision oncology.

[Immunotherapy for gastrointestinal cancer]. / Immuntherapie bei gastrointestinalen Tumoren.

Cancers of gastrointestinal tract make up the largest group of solid tumour diseases in Germany. The prognosis at diagnosis is often critical. Drug therapies reduce the risk of relapse after resection and can halt the progression of metastatic disease. Immunotherapies contribute increasingly to the treatment of gastrointestinal tumours. Monoclonal antibodies (mAB) against surface receptors from the epidermal growth factor receptor family (EGFR, Her2) are well established. The effect is partly based on the interruption of the oncogenic downstream signalling cascades and partly on immune effector mechanisms such as antibody-dependent cellular cytotoxicity. In clinical practice mAB directed against programmed cell death protein 1 (PD-1), its ligand (PD-L1) and cytotoxic T-lymphocyte-associated protein-4 (CTLA-4) - so-called immune checkpoint inhibitors - play an increasing role and change the natural history of some subgroups of gastrointestinal cancers, especially those with deficient DNA mismatch repair which leads to genomic microsatellite instability.

Plasma EBV DNA as a prognostic factor in EBV associated gastric cancer: a multicenter, prospective study (EBV PRESAGE study).

Purpose: The Cancer Genome Atlas Research Network identified Epstein-Barr-Virus (EBV)-positive gastric cancer as a distinct molecular subtype. The prevalence is 8-9% and the histological examination shows pronounced lymphocytic infiltration, elevated levels of IFN-γ and consequently overexpression of PD-L1. The role of plasma EBV DNA load as a prognostic factor in patients with this cancer subtype is still to be defined. Methods and analysis: The present multicenter prospective observational study "EBV PRESAGE", involving German and Italian cancer centers, aims to evaluate the prognostic role of plasma EBV DNA in EBV-related gastric cancer (GC). The objective is to study the association between plasma EBV DNA load at different consecutive time points and the patient's prognosis. Every patient with a new diagnosis of gastric cancer (including gastroesophageal junction adenocarcinoma) will be screened for Epstein-Barr encoded small Region (EBER) on tissue biopsies using in situ hybridization (ISH). If EBER ISH is positive, blood analysis for plasma EBV DNA will be conducted. The plasma EBV quantitative analysis will be centralized, and extraction, detection, and quantification of EBV DNA in plasma samples will be performed using real-time PCR. Discussion: We hypothesized that plasma EBV DNA represents a non-invasive tool for monitoring EBV-related GC and might be valuable as a prognostic marker.

Nivolumab and ipilimumab in recurrent or refractory cancer of unknown primary: a phase II trial.

Cancer of unknown primary has a dismal prognosis, especially following failure of platinum-based chemotherapy. 10-20% of patients have a high tumor mutational burden (TMB), which predicts response to immunotherapy in many cancer types. In this prospective, non-randomized, open-label, multicenter Phase II trial (EudraCT 2018-004562-33; NCT04131621), patients relapsed or refractory after platinum-based chemotherapy received nivolumab and ipilimumab following TMBhigh vs. TMBlow stratification. Progression-free survival (PFS) represented the primary endpoint; overall survival (OS), response rates, duration of clinical benefit and safety were the secondary endpoints. The trial was prematurely terminated in March 2021 before reaching the preplanned sample size (n = 194). Among 31 evaluable patients, 16% had a high TMB ( > 12 mutations/Mb). Overall response rate was 16% (95% CI 6-34%), with 7.7% (95% CI 1-25%) vs. 60% (95% CI 15-95%) in TMBlow and TMBhigh, respectively. Although the primary endpoint was not met, high TMB was associated with better median PFS (18.3 vs. 2.4 months) and OS (18.3 vs. 3.6 months). Severe immune-related adverse events were reported in 29% of cases. Assessing on-treatment dynamics of circulating tumor DNA using combined targeted hotspot mutation and shallow whole genome sequencing as part of a predefined exploratory analysis identified patients benefiting from immunotherapy irrespective of initial radiologic response.

Comparative bioinformatic analysis of KRAS, STK11 and KEAP1 (co-)mutations in non-small cell lung cancer with a special focus on KRAS G12C.

OBJECTIVES: Mutations in STK11 (STK11MUT) and KEAP1 (KEAP1MUT) occur frequently in non-small cell lung cancer (NSCLC) and are often co-mutated with KRAS. Several studies linked the co-occurrence of KRASMUT + STK11MUT, as well as KRASMUT + KEAP1MUT to reduced response to immune checkpoint inhibitors (ICI) and even a negative impact on survival. Data focusing STK11 + KEAP1 co-mutations or the triple mutation (KRAS + STK11 + KEAP1) are scarce. The recent availability of KRAS-G12C inhibitors increases the clinical relevance of those co-mutations in KRAS-mutated NSCLC. MATERIALS AND METHODS: We present a comprehensive bioinformatic analysis encompassing six datasets retrieved from cBioPortal. RESULTS: Independent of the treatment, triple mutations and STK11MUT + KEAP1MUT were significantly associated with a reduced overall survival (OS). Across treatments, OS of patients with a KRAS G12C triple mutation was significantly reduced compared to patients with KRAS G12C-only. Under ICI-therapy, there was no significant difference in OS between patients harboring the KRAS G12C-only and patients with the KRAS G12C triple mutation, but a significant difference between patients harboring KRAS non-G12C and KRAS non-G12C triple mutations. Triple mutated primary tumors showed a significantly increased frequency of distant metastases to bone and adrenal glands compared to KRAS-only mutated tumors. Additionally, our drug response analysis in cancer cell lines harboring the triple mutations revealed the WNT pathway inhibitor XAV-939 as a potential future drug candidate for this mutational situation. CONCLUSION: The triple mutation status may serve as a negative prognostic and predictive factor across treatments compared to KRASMUT-only. KRAS G12C generally seems to be a negative predictive marker for ICI-therapy.

Modifying immune responses to adeno-associated virus vectors by capsid engineering.

De novo immune responses are considered major challenges in gene therapy. With the aim to lower innate immune responses directly in cells targeted by adeno-associated virus (AAV) vectors, we equipped the vector capsid with a peptide known to interfere with Toll-like receptor signaling. Specifically, we genetically inserted in each of the 60 AAV2 capsid subunits the myeloid differentiation primary response 88 (MyD88)-derived peptide RDVLPGT, known to block MyD88 dimerization. Inserting the peptide neither interfered with capsid assembly nor with vector production yield. The novel capsid variant, AAV2.MB453, showed superior transduction efficiency compared to AAV2 in human monocyte-derived dendritic cells and in primary human hepatocyte cultures. In line with our hypothesis, AAV2.MB453 and AAV2 differed regarding innate immune response activation in primary human cells, particularly for type I interferons. Furthermore, mice treated with AAV2.MB453 showed significantly reduced CD8+ T cell responses against the transgene product for different administration routes and against the capsid following intramuscular administration. Moreover, humoral responses against the capsid were mitigated as indicated by delayed IgG2a antibody formation and an increased NAb50. To conclude, insertion of the MyD88-derived peptide into the AAV2 capsid improved early steps of host-vector interaction and reduced innate and adaptive immune responses.

Capsid-modified adeno-associated virus vectors as novel vaccine platform for cancer immunotherapy.

Immunotherapy has significantly improved treatment outcomes in various cancer entities. To enhance immunogenicity and efficacy, and to further broaden its applicability, co-administration of anti-tumor vaccines is considered as a promising strategy. Here, we introduce adeno-associated virus (AAV) vectors, widely used for in vivo gene therapy, as a potent cancer vaccine platform. Our AAV vector-based vaccine combines antigen display on the capsid surface with a vector-mediated antigen overexpression targeting different components of the immune system in a unique chronological order by a single intramuscular application. Thereby, both profound and long-lasting antigen-specific T and B cell immune responses were induced. Moreover, mice receiving the vaccine were protected against tumor growth, demonstrating its efficacy in two tumor models, including the low immunogenic and aggressive B16/F10-Ova melanoma model. Remarkably, this approach was even effective in conditions of a late tumor challenge, i.e., 80 days post-vaccination, between 88% (B16/F10-Ova melanoma) and 100% (EG7 thymoma) of mice remained tumor free. Thus, decorating AAV vector particles with antigens by capsid engineering represents a potent vaccine concept for applications in cancer immunotherapy. Its modular and versatile "plug-and-play" framework enables the use of tumor antigens of choice and the easy implementation of additional modifications to enhance immunogenicity further.

[What is confirmed in the treatment of colon cancer?] / Was ist gesichert in der Therapie des Kolonkarzinoms.

Colorectal cancer is the second most common cancer diagnosed in Germany and is the third most frequent cause of cancer-related death in both males and females. The majority of colorectal cancers occur via the adenoma-carcinoma sequence of origin. This means that colorectal cancers can be endoscopically detected in premalignant stages and can be curatively treated within the framework of early detection. Screening colonoscopy and, to a lesser extent, fecal occult blood testing, have led to a reduction in the colon cancer-related incidence and mortality. The acceptance and the use of screening colonoscopy should therefore be developed further. Treatment strategies for colorectal cancer are based on TNM staging, supplemented by anatomical and histopathological risk features as well as individual patient characteristics and treatment preferences. The molecular tumor profile is increasingly used to complement decision-making in the surgical, adjuvant and palliative treatment of colorectal cancer. Colon and rectal cancer have many similarities; however, they differ in the preoperative, surgical and adjuvant treatment strategies. This article focuses on colon cancer.

Hepatocellular Carcinoma Is a Natural Target for Adeno-Associated Virus (AAV) 2 Vectors.

Although therapeutic options are gradually improving, the overall prognosis for patients with hepatocellular carcinoma (HCC) is still poor. Gene therapy-based strategies are developed to complement the therapeutic armamentarium, both in early and late-stage disease. For efficient delivery of transgenes with antitumor activity, vectors demonstrating preferred tumor tropism are required. Here, we report on the natural tropism of adeno-associated virus (AAV) serotype 2 vectors for HCC. When applied intravenously in transgenic HCC mouse models, similar amounts of vectors were detected in the liver and liver tumor tissue. In contrast, transduction efficiency, as indicated by the level of transgene product, was moderate in the liver but was elevated up to 19-fold in mouse tumor tissue. Preferred transduction of HCC compared to hepatocytes was confirmed in precision-cut liver slices from human patient samples. Our mechanistic studies revealed that this preference is due to the improved intracellular processing of AAV2 vectors in HCC, resulting, for example, in nearly 4-fold more AAV vector episomes that serve as templates for gene transcription. Given this background, AAV2 vectors ought to be considered to strengthen current-or develop novel-strategies for treating HCC.

[Gastric Cancer: diagnosis and current treatment strategies]. / Diagnostik und Therapie des Magenkarzinoms.

Gastric and esophago-gastric junction (EGJ) adenocarcinoma are leading causes of cancer mortality and morbidity worldwide. In this short update article, we outline novel key developments in this field. Molecular defined subtypes can guide treatment decisions and create a roadmap for development of future agents in distinct subgroups of gastric cancer. In locally advanced EGJ cancer chemo-radiotherapy or perioperative chemotherapy are recommended treatment strategies. The FLOT regimen has evolved as a new standard for perioperative chemotherapy due to improved survival outcomes. For gastric cancer with limited metastasis, multimodality treatment approaches are under investigation. Systemic treatment over several lines along with best supportive care represents a standard in the management of metastatic disease. First line treatment should include trastuzmab in case of Her2 positivity. Immune checkpoint inhibitors are very effective in microsatellite instable tumors even in late treatment lines. In perspective, checkpoint inhibitors hold promise to become part of the standard treatment in the near future and novel Her2 targeted treatment approaches currently under development show promising results.

Biomarkers related to fatty acid oxidative capacity are predictive for continued weight loss in cachectic cancer patients.

BACKGROUND: Cachexia is characterized by a negative protein and energy balance leading to loss of adipose tissue and muscle mass. Cancer cachexia negatively impacts treatment tolerability and prognosis. Supportive interventions should be initiated as early as possible. Biomarkers for early prediction of continuing weight loss during the course of disease are currently lacking. METHODS: In this pilot, observational, cross-sectional, case-control study, cachectic cancer patients undergoing systemic first-line cancer treatment were matched 2:1 with healthy controls according to age, gender and body mass index. Alterations in amino acid and energy metabolism, as indicated by acylcarnitine levels, were analysed using mass spectrometry in plasma samples (PS) and dried blood specimen (DBS). Welch's two-sample t-test was used for comparative analysis of metabolites between cancer patients and healthy matched controls and to identify the metabolomic profiles related to weight loss across different time points. A linear regression model was applied to correlate weight loss and single metabolites as predictor variables. Finally, metabolite pathway enrichment analyses were performed. RESULTS: Eighteen cases (14 male and 4 female) and 36 paired controls were enrolled. There was a good correlation between baseline PS and DBS of healthy controls for the levels of most amino acids but not for acylcarnitine. Amino acid levels related to cancer metabolism were significantly altered in cancer patients compared with controls in both DBS and PS for arginine, citrulline, histidine and ornithine and in DBS only for asparagine, glutamine, methylhistidine, methionine, ornithine, serine, threonine and leucine/isoleucine. Metabolite enrichment analysis in PS of cancer patients revealed histidine metabolism activation (P = 0.0025). Baseline acylcarnitine analysis in DBS was indicative for alterations of the mitochondrial carnitine shuttle, related to ß-oxidation: The ratio palmitoylcarnitine/acylcarnitine (Q2) and the ratio palmitoylcarnitine + octadecenoylcarnitine/acylcarnitine (Q3) were predictive for early weight loss (P < 0.0001) and weight loss during follow-up. Activation of tryptophan metabolism (P = 0.035) in DBS and PS and activation of serine/glycine metabolism (P = 0.017) in PS were also related to early weight loss and across successive time points. CONCLUSIONS: We found alterations in amino acid levels most likely attributable to cancer metabolism itself in cancer patients compared with controls. Baseline DBS represent a valuable analyte to study energy metabolism related to cancer cachexia. Acylcarnitine patterns (Q2, Q3) predicted further weight loss in cachectic cancer patients undergoing systemic therapy, and pathway analyses indicated involvement of the serine/glycine and the tryptophan pathway in this condition. Validation in larger cohorts is warranted.

Molecular Targets for Gastric Cancer Treatment and Future Perspectives from a Clinical and Translational Point of View.

Gastric cancer is a leading cause of cancer death worldwide. Systemic treatment comprising chemotherapy and targeted therapy is the standard of care in advanced/metastatic gastric cancer. Comprehensive molecular characterization of gastric adenocarcinomas by the TCGA Consortium and ACRG has resulted in the definition of distinct molecular subtypes. These efforts have in parallel built a basis for the development of novel molecularly stratified treatment approaches. Based on this molecular characterization, an increasing number of specific genomic alterations can potentially serve as treatment targets. Consequently, the development of promising compounds is ongoing. In this review, key molecular alterations in gastric and gastroesophageal junction cancers will be addressed. Finally, the current status of the translation of targeted therapy towards clinical applications will be reviewed.

Pyroptotic and Necroptotic Cell Death in the Tumor Microenvironment and Their Potential to Stimulate Anti-Tumor Immune Responses.

Cancer remains the second most common cause of death worldwide affecting around 10 million patients every year. Among the therapeutic options, chemotherapeutic drugs are widely used but often associated with side effects. In addition, toxicity against immune cells may hamper anti-tumor immune responses. Some chemotherapeutic drugs, however, preserve immune functions and some can even stimulate anti-tumor immune responses through the induction of immunogenic cell death (ICD) rather than apoptosis. ICD stimulates the immune system by several mechanisms including the release of damage-associated molecular patterns (DAMPs) from dying cells. In this review, we will discuss the consequences of inducing two recently characterized forms of ICD, i.e., pyroptosis and necroptosis, in the tumor microenvironment (TME) and the perspectives they may offer to increase the immunogenicity of the so-called cold tumors and to stimulate effective anti-tumor immune responses.

Towards Clinical Implementation of Adeno-Associated Virus (AAV) Vectors for Cancer Gene Therapy: Current Status and Future Perspectives.

Adeno-associated virus (AAV) vectors have gained tremendous attention as in vivo delivery systems in gene therapy for inherited monogenetic diseases. First market approvals, excellent safety data, availability of large-scale production protocols, and the possibility to tailor the vector towards optimized and cell-type specific gene transfer offers to move from (ultra) rare to common diseases. Cancer, a major health burden for which novel therapeutic options are urgently needed, represents such a target. We here provide an up-to-date overview of the strategies which are currently developed for the use of AAV vectors in cancer gene therapy and discuss the perspectives for the future translation of these pre-clinical approaches into the clinic.

Conceptual framework for precision cancer medicine in Germany: Consensus statement of the Deutsche Krebshilfe working group 'Molecular Diagnostics and Therapy'.

Precision cancer medicine (PCM) holds great promises to offer more effective therapies to patients based on molecular profiling of their individual tumours. Although the PCM approach seems intuitive, multiple conceptional and structural challenges interfere with the broad implementation of PCM into clinical practice. Accordingly, concerted national and international efforts are needed to guide the further development and broad adoption of PCM in Germany. With support of the 'German Cancer Aid' (Deutsche Krebshilfe [DKH]) a task force 'Molecular Diagnostics and Therapy' was implemented. In two workshops supported by the DKH, delegates from the fourteen comprehensive cancer centresidentified key topics essential to implement quality-guided, harmonized and adaptable PCM. Based on an online questionnaire and using a modified Delphi approach, nine statements were drafted and evaluated within the group. These statements could serve as a basis to define a collaborative strategy for PCM in the future with the aim to sustain and further improve its quality.

Prognostic role of body composition parameters in gastric/gastroesophageal junction cancer patients from the EXPAND trial.

BACKGROUND: Body fat and/or muscle composition influences prognosis in several cancer types. For advanced gastric and gastroesophageal junction cancer, we investigated which body composition parameters carry prognostic information beyond well-established clinical parameters using robust model selection strategy such that parameters identified can be expected to generalize and to be reproducible beyond our particular data set. Then we modelled how differences in these parameters translate into survival outcomes. METHODS: Fat and muscle parameters were measured on baseline computed tomography scans in 761 patients with advanced gastric or gastroesophageal junction cancer from the phase III EXPAND trial, undergoing first-line chemotherapy. Cox regression analysis for overall survival (OS) and progression-free survival (PFS) included body composition parameters and clinical prognostic factors. All continuous variables were entered linearly into the model as there was no evidence of non-linear prognostic impact. For transferability, the final model included only parameters that were picked by Bayesian information criterion model selection followed by bootstrap analysis to identify the most robust model. RESULTS: Muscle and fat parameters formed correlation clusters without relevant between-cluster correlation. Mean muscle attenuation (MA) clusters with the fat parameters. In multivariate analysis, MA was prognostic for OS (P < 0.0001) but not for PFS, while skeletal muscle index was prognostic for PFS (P = 0.02) but not for OS. Worse performance status Eastern Cooperative Oncology Group (ECOG 1/0), younger age (on a linear scale), and the number of metastatic sites were strong negative clinical prognostic factors for both OS and PFS. MA remained in the model for OS (P = 0.0001) following Bayesian information criterion model selection in contrast to skeletal muscle index that remained prognostic for PFS (P = 0.009). Applying stricter criteria for transferability, MA represented the only prognostic body composition parameter for OS, selected in >80% of bootstrap replicates. Finally, Cox model-derived survival curves indicated that large differences in MA translate into only moderate differences in expected OS in this cohort. CONCLUSIONS: Among body composition parameters, only MA has robust prognostic impact for OS. Data suggest that treatment approaches targeting muscle quality are unlikely to prolong OS noticeably on their own in advanced gastric cancer patients, indicating that multimodal approaches should be pursued in the future.

High prevalence of severe hypovitaminosis D in patients with advanced gastric cancer treated with first-line chemotherapy with or without anti-EGFR-directed monoclonal antibody (EXPAND trial) showing no prognostic impact.

PURPOSE: The goal of our analysis was to study pretherapeutic circulating 25-OHD plasma levels in patients with previously untreated advanced gastric cancer treated in the randomised controlled phase III Erbitux (cetuximab) in combination with Xeloda (capecitabine) and cisplatin in advanced esophago-gastric cancer (EXPAND) trial (NCT00678535) and to explore whether low 25-OHD plasma levels are associated with worse prognosis and may compromise the clinical efficacy of cetuximab. METHODS: Six hundred thirty patients with available pretherapeutic 25-OHD plasma levels and treated with chemotherapy based on capecitabine and cisplatin, or chemotherapy and cetuximab, were included. The Cox proportional hazard regression model was used to analyse the association between low 25-OHD and survival in both treatment arms. RESULTS: Majority of study patients were found to have severe vitamin D deficiency. No prognostic impact of 25-OHD plasma levels could be found in our patient cohort, and there was no indication of an interference of 25-OHD plasma levels and the efficacy of treatment with the anti-epidermal growth factor receptor monoclonal antibody cetuximab. CONCLUSIONS: Although majority of patients with advanced gastric cancer show hypovitaminosis D deficiency, there is no proof for a negative impact on survival or reduced treatment response. A prospective study is needed to investigate the potential benefit of vitamin D supplementation in this patient cohort during first-line chemotherapy.