Image-based consensus molecular subtyping in rectal cancer biopsies and response to neoadjuvant chemoradiotherapy.

The development of deep learning (DL) models to predict the consensus molecular subtypes (CMS) from histopathology images (imCMS) is a promising and cost-effective strategy to support patient stratification. Here, we investigate whether imCMS calls generated from whole slide histopathology images (WSIs) of rectal cancer (RC) pre-treatment biopsies are associated with pathological complete response (pCR) to neoadjuvant long course chemoradiotherapy (LCRT) with single agent fluoropyrimidine. DL models were trained to classify WSIs of colorectal cancers stained with hematoxylin and eosin into one of the four CMS classes using a multi-centric dataset of resection and biopsy specimens (n = 1057 WSIs) with paired transcriptional data. Classifiers were tested on a held out RC biopsy cohort (ARISTOTLE) and correlated with pCR to LCRT in an independent dataset merging two RC cohorts (ARISTOTLE, n = 114 and SALZBURG, n = 55 patients). DL models predicted CMS with high classification performance in multiple comparative analyses. In the independent cohorts (ARISTOTLE, SALZBURG), cases with WSIs classified as imCMS1 had a significantly higher likelihood of achieving pCR (OR = 2.69, 95% CI 1.01-7.17, p = 0.048). Conversely, imCMS4 was associated with lack of pCR (OR = 0.25, 95% CI 0.07-0.88, p = 0.031). Classification maps demonstrated pathologist-interpretable associations with high stromal content in imCMS4 cases, associated with poor outcome. No significant association was found in imCMS2 or imCMS3. imCMS classification of pre-treatment biopsies is a fast and inexpensive solution to identify patient groups that could benefit from neoadjuvant LCRT. The significant associations between imCMS1/imCMS4 with pCR suggest the existence of predictive morphological features that could enhance standard pathological assessment.

The efficacy of ferroptosis-inducing compounds IKE and RSL3 correlates with the expression of ferroptotic pathway regulators CD71 and SLC7A11 in biliary tract cancer cells.

INTRODUCTION: Biliary tract cancer (BTC) is a lethal disease with a bad overall survivability, partly arising from inadequate therapeutic alternatives, detection at a belated stage, and a resistance to common therapeutic approaches. Ferroptosis is a form of programmed cell death that depends on reactive oxygen species (ROS) and iron, causing excessive peroxidation of polyunsaturated fatty acids (PUFAs). Therefore, the objective of this investigation is, whether ferroptosis can be induced in BTC in vitro and whether this induction is dependent on specific molecular markers. METHODS: The study conducted resazurin assay and IC25/50 calculation to explore the possible cytotoxic outcomes of different classes of ferroptosis-inducing substances (FINs) on a comprehensive in vitro model of 11 BTC cell lines. Combinatory treatments with different cell death inhibitors were performed to evaluate the magnitude of ferroptosis induction. To ascertain whether ferroptotic cell death occurred, liperfluo and iron assay kits were employed to evaluate lipid ROS and intracellular iron abundance. Potential biomarkers of ferroptosis sensitivity were then assessed via western blot analysis, a rtPCR panel and functional assay kits. RESULTS: The study found that different FINs reduced cell viability in a cell line-dependent manner. In addition, we measured increased lipid ROS and intracellular Fe2+ levels upon exposure to FINs in BTC cells. Combining FINs with inhibitors of ferroptosis, necroptosis or apoptosis suggests the occurrence of ferroptotic events in BTC cell lines CCC-5, HuH-28 and KKU-055. Furthermore, we found that BTC cells display a heterogeneous profile regarding different molecular genes/markers of ferroptosis. Subsequent analysis revealed that sensitivity of BTC cells towards IKE and RSL3 positively correlated with CD71 and SLC7A11 protein expression. CONCLUSION: Our results demonstrate that induction of ferroptosis is a promising approach to inhibit BTC cell growth and that the sensitivity of BTC cells towards ferroptosis induction might be dependent on molecular markers such as CD71 and SLC7A11.

Enhancing anti-CD274 (PD-L1) targeting through combinatorial immunotherapy with bispecific antibodies and fusion proteins: from preclinical to phase II clinical trials.

INTRODUCTION: Immune checkpoint inhibitors have achieved great success in the treatment of many different types of cancer. Programmed cell death protein ligand 1 (PD-L1, CD274) is a major immunosuppressive immune checkpoint and a target for several already approved monoclonal antibodies. Despite this, novel strategies are under development, as the overall response remains low. AREAS COVERED: In this review, an overview of the current biomarkers for response to PD-L1 inhibitor treatment is given, followed by a discussion of potential novel biomarkers, including tumor mutational burden and circulating tumor DNA. Combinatorial immunotherapy is a potential novel strategy to increase the response to PD-L1 inhibitor treatment and currently, several interesting bispecific antibodies as well as bispecific fusion proteins are undergoing early clinical investigation. We focus on substances targeting PD-L1 and a secondary target, and a secondary immunomodulatory target like CTLA-4, TIGIT, or CD47. EXPERT OPINION: Overall, the presented studies show anti-tumor activity of these combinatorial immunotherapeutic approaches. However, still relatively low response rates suggest a need for better biomarkers.

Oncogenic MTOR signaling axis compensates BTK inhibition in a Chronic Lymphocytic Leukemia patient with Richter Transformation: A Case Report and Review of the Literature.

INTRODUCTION: Targeting the B cell receptor (BCR) pathway via ibrutinib, a specific inhibitor of Bruton's tyrosine kinase, has shown marked clinical efficacy in treatment of patients with chronic lymphocytic leukemia (CLL), thus becoming a preferred first line option independent of risk factors. However, acquired resistance to ibrutinib poses a major clinical problem and requires the development of novel treatment combinations to increase efficacy and counteract resistance development and clinical relapse rates. CASE PRESENTATION: In this study, we performed exome and transcriptome analyses of an ibrutinib resistant CLL patient in order to investigate genes and expression patterns associated with ibrutinib resistance. Here we provide evidence that ibrutinib resistance can be attributed to aberrant mammalian target of rapamycin (MTOR) signaling. CONCLUSION: Thus, our study proposes that combined use of MTOR inhibitors with ibrutinib could be a possible option to overcome therapy resistance in ibrutinib treated patients.

Gene expression inhibitors for the treatment of liver fibrosis: drugs under preclinical and early clinical investigation.

INTRODUCTION: Liver fibrosis represents an unmet medical condition with growing incidence and only limited therapeutic options. Interfering with dysregulated gene expression was considered a specific treatment approach, and we are here reviewing the current options to modulate transcription and translation with small molecule inhibitors of involved enzymes, transcription factors or by using non-coding RNA molecules (RNA interference) or DNA antisense oligonucleotides. Despite promising results in preclinical models, only limited data are available from studies in humans. AREAS COVERED: This expert opinion provides a general overview of how to interfere with gene expression (transcription and translation) and highlighting recent achievements in liver fibrosis. EXPERT OPINION: Many compounds that were explored to modulate gene expression in liver fibrosis (models) were developed as anti-cancer agents. Their use in humans with impaired liver function is often impaired by the lack of specificity to inhibit only fibrosis-related genes in the liver and by associated general toxicity and narrow therapeutic windows. RNAi approaches show a higher degree of specificity and potentially less systemic toxicity. Clinical development in liver fibrosis requires close interaction between pharmaceutical companies and regulatory authorities to address topics like relevant (surrogate) endpoints to achieve meaningful readouts faster.

Management of metastatic colorectal cancer in patients ≥70 years - a single center experience.

Background: Age-standardized mortality rates for metastatic colorectal cancer (mCRC) are highest among elderly patients. In current clinical guidelines, treatment recommendations for this patient population are based on a limited number of clinical trials. Patients and methods: In this monocentric, retrospective analysis we characterized patients aged ≥70 years undergoing systemic therapy for mCRC and overall survival (OS) was investigated. Results: We included 117 unselected, consecutive mCRC patients aged ≥70 years undergoing systemic therapy for mCRC between February 2009 and July 2022. Median OS was 25.6 months (95% CI: 21.8-29.4). The median age was 78 years (range: 70-90) and 21%, 48%, 26% and 5% had an ECOG performance score of 0, 1, 2, and 3, respectively. The median number of systemic therapy lines was 2 (range: 1-5). The choice of first-line chemotherapy backbone (doublet/triplet versus mono) did not impact OS (HR: 0.83, p=0.50) or the probability of receiving subsequent therapy (p=0.697). Metastasectomy and/or local ablative treatment in the liver, lung, peritoneum and/or other organs were applied in 26 patients (22%) with curative intent. First-line anti-EGFR-based therapy showed a trend towards longer OS compared to anti-VEGF-based therapy or chemotherapy alone in left-sided mCRC (anti-EGFR: 39.3 months versus anti-VEGF: 27.3 months versus chemotherapy alone: 13.8 months, p=0.105). In multivariable analysis, metastasectomy and/or local ablative treatment with curative intent (yes versus no, HR: 0.22, p<0.001), the ECOG performance score (2 versus 0, HR: 3.07, p=0.007; 3 versus 0, HR: 3.66, p=0.053) and the presence of liver metastases (yes versus no, HR: 1.79, p=0.049) were independently associated with OS. Conclusions: Our findings corroborate front-line monochemotherapy in combination with targeted therapy as the treatment of choice for elderly mCRC patients with palliative treatment intent. Metastasectomy and/or local ablative treatment with curative intent are feasible and may improve OS in selected elderly mCRC patients.

Ouabain at nanomolar concentrations is cytotoxic for biliary tract cancer cells.

Biliary tract cancer is a deadly disease with limited therapeutic options. Ouabain is a well-known inhibitor of the pumping function of Na+/K+-ATPase, though there is evidence that low concentrations of ouabain lead to a reduction of cell viability of cancer cells independent of its inhibition of the pumping function of the Na+/K+-ATPase. Regarding the impact of ouabain on biliary tract cancer, no data is currently available. Therefore, we aimed for a first-time investigation of ouabain as a potential anti-neoplastic biliary tract cancer agent using comprehensive human biliary tract cancer in vitro models. We found that ouabain has a strong cell line-dependent cytotoxic effect with IC50 levels in the (low) nanomolar-range and that this effect was not associated with the mRNA expression levels of the Na+/K+-ATPase α, ß and fxyd-subunits. Regarding the mode of cytotoxicity, we observed induction of apoptosis in biliary tract cancer cells upon treatment with ouabain. Interestingly, cytotoxic effects of ouabain at sub-saturating (< µM) levels were independent of cellular membrane depolarization and changes in intracellular sodium levels. Furthermore, using a 3D cell culture model, we found that ouabain disturbs spheroid growth and reduces the viability of biliary tract cancer cells within the tumor spheroids. In summary, our data suggest that ouabain possesses anti-biliary tract cancer potential at low µM-concentration in 2D and 3D in vitro biliary tract cancer models and encourage further detailed investigation.

The SAlzburg PEritoneal SUrface CAlculator (SAPESUCA): The First Web-Based Application for Peritoneal Surface Area Quantification.

(1) Background: Peritoneal metastasized colorectal cancer is associated with a worse prognosis. The combination of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) showed promising results in selected patients, but standardization is lacking so far. We present the first tool enabling standardized peritoneal surface area (PSA) quantification in patients undergoing CRS and HIPEC: The SAlzburg PEritoneal SUrface CAlculator (SAPESUCA). (2) Methods: SAPESUCA was programmed using the R-Shiny framework. The application was validated in 23 consecutive colon cancer patients who received 27 closed oxaliplatin-based HIPECs between 2016 and 2020. The programming algorithm incorporates the patient's body surface area and its correlated peritoneal surface area (PSA) based on the 13 Peritoneal Cancer Index (PCI) regions. (3) Results: Patients' median age was 56 years. Median PCI was 9. SAPESUCA revealed a mean PSA of 18,613 cm2 ± 1951 of all patients before compared to 13,681 cm2 ± 2866 after CRS. The Central PCI region revealed the highest mean peritonectomy extent (1517 cm2 ± 737). The peritonectomy extent correlated significantly with PCI score and postoperative morbidity. The simulated mean oxaliplatin dose differed significantly before and after CRS (558 mg/m2 ± 58.4 vs. 409 mg/m2 ± 86.1; p < 0.0001). (4) Conclusion: SAPESUCA is the first free web-based app for standardized determination of the resected and remaining PSA after CRS. The tool enables chemotherapeutic dose adjustment to the remaining PSA.

HDACs as an emerging target in endocrine tumors: a comprehensive review.

INTRODUCTION: The pathogenic role of deregulated histone (de-)acetylation by histone deacetyles (HDACs) has been demonstrated in several human cancers. While some HDAC inhibitors (HDACi) have been approved for individual entities, for endocrine tumors such translation into clinical practice has not yet been achieved. AREAS COVERED: Relevant results identified by structured searches in PubMed as well as in reference lists are summarized in a narrative review to discuss the current knowledge of HDAC involvement and their therapeutic relevance in endocrine tumors. For thyroid, neuroendocrine, and adrenal tumors, various oncogenic mechanisms of HDAC deregulation and effects of HDAC inhibitors (HDACi) have been identified in preclinical studies including direct cancer cell toxicity and modification of differentiation status. EXPERT OPINION: Based on positive pre-clinical results, the research on HDAC (inhibition) in the various endocrine tumors should be intensified - yet, it needs to be considered that i) HDACs' oncogenic actions might constitute only a part of epigenetic mechanisms driving cancer, ii) individual HDAC has different roles in different endocrine tumor entities, iii) inhibition of HDACs might be especially attractive in combination with conventional or other targeted therapies, and iv) new HDAC-inhibiting drugs with improved specificity or functionally modified HDACi might further improve their efficacy.

Evaluation of Tazemetostat as a Therapeutically Relevant Substance in Biliary Tract Cancer.

Biliary tract cancer (BTC) is a gastrointestinal malignancy associated with a poor survival rate. Current therapies encompass palliative and chemotherapeutic treatment as well as radiation therapy, which results in a median survival of only one year due to standard therapeutic ineffectiveness or resistance. Tazemetostat is an FDA-approved inhibitor of enhancer of Zeste homolog 2 (EZH2), a methyltransferase involved in BTC tumorigenesis via trimethylation of histone 3 at lysine 27 (H3K27me3), an epigenetic mark associated with silencing of tumor suppressor genes. Up to now, there are no data available regarding tazemetostat as a possible treatment option against BTC. Therefore, the aim of our study is a first-time investigation of tazemetostat as a potential anti-BTC substance in vitro. In this study, we demonstrate that tazemetostat affects cell viability and the clonogenic growth of BTC cells in a cell line-dependent manner. Furthermore, we found a strong epigenetic effect at low concentrations of tazemetostat, which was independent of the cytotoxic effect. We also observed in one BTC cell line that tazemetostat increases the mRNA levels and protein expression of the tumor suppressor gene Fructose-1,6-bisphosphatase 1 (FBP1). Interestingly, the observed cytotoxic and epigenetic effects were independent of the mutation status of EZH2. To conclude, our study shows that tazemetostat is a potential anti-tumorigenic substance in BTC with a strong epigenetic effect.

Real-world Data of Palliative First-line Checkpoint Inhibitor Therapy for Head and Neck Cancer.

BACKGROUND/AIM: Pembrolizumab alone or combined with chemotherapy is now approved in PD-L1-positive patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Since real-world data are pending, our goal was to evaluate the efficacy and safety of immune checkpoint inhibitor (CPI) therapy in an unselected cohort of patients with SCCHN. PATIENTS AND METHODS: We analyzed 78 patients with recurrent or metastatic SCCHN from three Austrian cancer centers that received CPI therapy alone or with chemotherapy as palliative first-line systemic treatment for this retrospective study. Patient characteristics, details on treatment, and survival were analyzed by a chart-based review. RESULTS: Of the 78 patients analyzed, 55 patients were treated with CPI alone (45 with Pembrolizumab, 10 with Nivolumab) and 23 patients received chemotherapy with a platinum and 5-FU in addition to CPI. With a median follow-up of twelve months, the median PFS of all patients was 4 months [95% confidence interval (CI)=2.2-5.8] and the median OS was 11 months (95% CI=7.1-14.9). The overall response and disease control rates were 20.5% and 46.1%, respectively. There was no statistically significant difference in clinical outcome between patient groups with a different combined positive score (CPS). The rate of reported immune related adverse events was comparable to existing data. CONCLUSION: Our findings confirm the results of the KEYNOTE-048 trial that CPI therapy alone or together with chemotherapy is an effective treatment for patients with recurrent or metastatic CPS-positive SCCHN.

Body composition dynamics and impact on clinical outcome in gastric and gastro-esophageal junction cancer patients undergoing perioperative chemotherapy with the FLOT protocol.

PURPOSE: Perioperative chemotherapy with FLOT constitutes a standard of care approach for locally advanced, resectable gastric or gastro-esophageal junction (GEJ) cancer. We aimed at investigating anthropometric, CT-based and FDG-PET-based body composition parameters and dynamics during this multidisciplinary approach and the impact on clinical outcomes. METHODS: This retrospective, single-center study was based on medical records and (FDG-PET)-CT images among gastric/GEJ cancer patients undergoing perioperative FLOT chemotherapy. RESULTS: Between 2016 and 2021, 46 gastric/GEJ cancer patients started perioperative FLOT at our tertiary cancer center (Salzburg, Austria). At a median follow-up of 32 months median PFS was 47.4 months and median OS was not reached. The skeletal muscle index (SMI, cm2/m2) turned out to be the only body composition parameter with a statistically significant decrease during pre-operative FLOT (51.3 versus 48.8 cm2/m2, p = 0.02). Neither pre-FLOT body mass index (BMI), nor SMI had an impact on the duration of pre-operative FLOT, the time interval from pre-operative FLOT initiation to surgery, the necessity of pre-operative or post-operative FLOT de-escalation or the likelihood of the start of postoperative chemotherapy. Pre-FLOT BMI (overweight versus normal, HR: 0.11, 95% CI: 0.02-0.65, p = 0.02) and pre-FLOT SMI (sarcopenia versus no sarcopenia, HR: 5.08, 95% CI: 1.27-20.31, p = 0.02) were statistically significantly associated with PFS in the multivariable analysis. CONCLUSION: The statistically significant SMI loss during pre-operative FLOT and the meaningful impact of baseline SMI and BMI on PFS argue for the implementation of a nutritional screening and support program prior to the initiation of pre-operative FLOT in clinical routine.

Hydrogen Sulfide Metabolizing Enzymes in the Intestinal Mucosa in Pediatric and Adult Inflammatory Bowel Disease.

Hydrogen sulfide (H2S) is a toxic gas that has important regulatory functions. In the colon, H2S can be produced and detoxified endogenously. Both too little and too much H2S exposure are associated with inflammatory bowel disease (IBD), a chronic intestinal disease mainly classified as Crohn's disease (CD) and ulcerative colitis (UC). As the pathogenesis of IBD remains elusive, this study's aim was to investigate potential differences in the expression of H2S-metabolizing enzymes in normal aging and IBD. Intestinal mucosal biopsies of 25 adults and 22 children with IBD along with those of 26 healthy controls were stained immunohistochemically for cystathionine-γ-lyase (CSE), 3-mercapto-sulfurtransferase (3-MST), ethylmalonic encephalopathy 1 protein (ETHE1), sulfide:quinone oxidoreductase (SQOR) and thiosulfate sulfurtransferase (TST). Expression levels were calculated by multiplication of the staining intensity and percentage of positively stained cells. Healthy adults showed an overall trend towards lower expression of H2S-metabolizing enzymes than healthy children. Adults with IBD also tended to have lower expression compared to controls. A similar trend was seen in the enzyme expression of children with IBD compared to controls. These results indicate an age-related decrease in the expression of H2S-metabolizing enzymes and a dysfunctional H2S metabolism in IBD, which was less pronounced in children.