Singlet oxygen-based photoelectrochemical detection of single-point mutations in the KRAS oncogene.

Single nucleotide point mutations in the KRAS oncogene occur frequently in human cancers, rendering them intriguing targets for diagnosis, early detection and personalized treatment. Current detection methods are based on polymerase chain reaction, sometimes combined with next-generation sequencing, which can be expensive, complex and have limited availability. Here, we propose a novel singlet oxygen (1O2)-based photoelectrochemical detection methodology for single-point mutations, using KRAS mutations as a case study. This detection method combines the use of a sandwich assay, magnetic beads and robust chemical photosensitizers, that need only air and light to produce 1O2, to ensure high specificity and sensitivity. We demonstrate that hybridization of the sandwich hybrid at high temperatures enables discrimination between mutated and wild-type sequences with a detection rate of up to 93.9%. Additionally, the presence of background DNA sequences derived from human cell-line DNA, not containing the mutation of interest, did not result in a signal, highlighting the specificity of the methodology. A limit of detection as low as 112 pM (1.25 ng/mL) was achieved without employing any amplification techniques. The developed 1O2-based photoelectrochemical methodology exhibits unique features, including rapidity, ease of use, and affordability, highlighting its immense potential in the field of nucleic acid-based diagnostics.

Single-organoid analysis reveals clinically relevant treatment-resistant and invasive subclones in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal diseases, characterized by a treatment-resistant and invasive nature. In line with these inherent aggressive characteristics, only a subset of patients shows a clinical response to the standard of care therapies, thereby highlighting the need for a more personalized treatment approach. In this study, we comprehensively unraveled the intra-patient response heterogeneity and intrinsic aggressive nature of PDAC on bulk and single-organoid resolution. We leveraged a fully characterized PDAC organoid panel (N = 8) and matched our artificial intelligence-driven, live-cell organoid image analysis with retrospective clinical patient response. In line with the clinical outcomes, we identified patient-specific sensitivities to the standard of care therapies (gemcitabine-paclitaxel and FOLFIRINOX) using a growth rate-based and normalized drug response metric. Moreover, the single-organoid analysis was able to detect resistant as well as invasive PDAC organoid clones, which was orchestrates on a patient, therapy, drug, concentration and time-specific level. Furthermore, our in vitro organoid analysis indicated a correlation with the matched patient progression-free survival (PFS) compared to the current, conventional drug response readouts. This work not only provides valuable insights on the response complexity in PDAC, but it also highlights the potential applications (extendable to other tumor types) and clinical translatability of our approach in drug discovery and the emerging era of personalized medicine.

The Quest for Circulating Biomarkers in Neuroendocrine Neoplasms: a Clinical Perspective.

OPINION STATEMENT: Given the considerable heterogeneity in neuroendocrine neoplasms (NENs), it appears unlikely that a sole biomarker exists capable of fully capturing all useful clinical aspects of these tumors. This is reflected in the abundant number of biomarkers presently available for the diagnosis, prognosis, and monitoring of NEN patients. Although assessment of immunohistochemical and radiological markers remains paramount and often obligatory, there has been a notable surge of interest in circulating biomarkers over the years given the numerous benefits associated with liquid biopsies. Currently, the clinic primarily relies on single-analyte assays such as the chromogranin A assay, but these are far from ideal because of limitations such as compromised sensitivity and specificity as well as a lack of standardization. Consequently, the quest for NEN biomarkers continued with the exploration of multianalyte markers, exemplified by the development of the NETest and ctDNA-based analysis. Here, an extensive panel of markers is simultaneously evaluated to identify distinct signatures that could enhance the accuracy of patient diagnosis, prognosis determination, and response to therapy prediction and monitoring. Given the promising results, the development and implementation of these multianalyte markers are expected to usher in a new era of NEN biomarkers in the clinic. In this review, we will outline both clinically implemented and more experimental circulating markers to provide an update on developments in this rapidly evolving field.

Novel therapeutic strategies in pancreatic cancer: moving beyond cytotoxic chemotherapy.

INTRODUCTION: Prognosis of patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) remains disappointing with a 5-year overall survival of only 3-5%. Compared to other cancers, the evolution in standard therapeutic options has been stagnant and polychemotherapy regimens (with well-known toxicity profile and resistance pattern) remain standard of care. Only for patients (5%-7%) with a breast cancer gene (BRCA) pathogenic germline variant, prognosis has improved by the use of olaparib (poly-ADP ribose polymerase (PARP) inhibitor). AREAS COVERED: This review covers emerging treatment strategies in the management of mPDAC. One of the main topics is the rigid and immunological cold tumor microenvironment (TME) of PDAC and the search for agents that impact this TME and/or engage the immune system. In addition, the use of next-generation sequencing (NGS) has elicited for some patients new targeted therapies directed at alterations in the RTK/RAS/MAPK pathway and the deoxyribonucleic acid (DNA) damage repair pathway. Other evolving treatment strategies are also discussed. EXPERT OPINION: The search for new, often combination, treatment strategies for mPDAC should be encouraged and implemented in early treatment lines given the significant decline of performance status of patients in later lines. NGS analysis should be used where available, although cost-effectiveness could be debatable.

Preoperative treatment with mFOLFIRINOX or Gemcitabine/Nab-paclitaxel +/- isotoxic high-dose stereotactic body Radiation Therapy (iHD-SBRT) for borderline resectable pancreatic adenocarcinoma (the STEREOPAC trial): study protocol for a randomised comparative multicenter phase II trial.

BACKGROUND: For patients with pancreatic ductal adenocarcinoma (PDAC), surgical resection remains the only potentially curative treatment. Surgery is generally followed by postoperative chemotherapy associated with improved survival, yet neoadjuvant therapy is a rapidly emerging concept requiring to be explored and validated in terms of treatment options and oncological outcomes. In this context, stereotactic body radiation (SBRT) appears feasible and can be safely integrated into a neoadjuvant chemotherapy regimen of modified FOLFIRINOX (mFFX) with promising benefits in terms of R0 resection, local control and survival. However, the optimal therapeutic sequence is still not known, especially for borderline resectable PDAC, and the role of adding SBRT to chemotherapy in the neoadjuvant setting needs to be evaluated in randomised controlled trials. The aim of the STEREOPAC trial is to assess the impact and efficacy of adding isotoxic high-dose SBRT (iHD-SBRT) to neoadjuvant mFFX or Gemcitabine/Nab-Paclitaxel (Gem/Nab-P) in patients with borderline resectable PDAC. METHODS: This is a randomised comparative multicentre phase II trial, planning to enrol patients (n = 256) diagnosed with a borderline resectable biopsy-confirmed PDAC. Patients will receive 4 cycles of mFFX (or 6 doses of Gem/Nab-P). After full disease restaging, non-progressive patients will be randomised for receiving either 4 additional mFFX cycles (or 6 doses of Gem/Nab-P) (Arm A), or 2 mFFX cycles (or 3 doses of Gem/Nab-P) + iHD-SBRT (35 to 55 Gy in 5 fractions) + 2 mFFX cycles (or 3 doses of Gem/Nab-P) (Arm B). Then curative surgery will be performed followed by adjuvant chemotherapy according to patient's condition. The co-primary endpoints are R0 resection and disease-free survival after the complete sequence strategy. The secondary endpoints include resection rate, overall survival, locoregional failure / distant metastasis free interval, pathologic complete response, toxicity, postoperative complications and quality of life assessment. DISCUSSION: This trial will help define the best neoadjuvant treatment sequence for borderline resectable PDAC and aims to evaluate if a total neoadjuvant treatment integrating iHD-SBRT improves the patients' oncological outcomes. TRIAL REGISTRATION: The study was registered at ClinicalTrails.gov (NCT05083247) on October 19th, 2021, and in the Clinical Trials Information System (CTIS) EU CT database (2022-501181-22-01) on July 2022.

Prospective comparison of [18F]AlF-NOTA-octreotide PET/MRI to [68Ga]Ga-DOTATATE PET/CT in neuroendocrine tumor patients.

BACKGROUND: Fluorine-18-labeled SSAs have the potential to become the next-generation tracer in SSTR-imaging in neuroendocrine tumor (NET) patients given their logistical advantages over the current gold standard gallium-68-labeled SSAs. In particular, [18F]AlF-OC has already shown excellent clinical performance. We demonstrated in our previous report from our prospective multicenter trial that [18F]AlF-OC PET/CT outperforms [68Ga]Ga-DOTA-SSA, but histological confirmation was lacking due to ethical and practical reasons. In this second arm, we therefore aimed to provide evidence that the vast majority of [18F]AlF-OC PET lesions are in fact true NET lesions by analyzing their MR characteristics on simultaneously acquired MRI. We had a special interest in lesions solely detected by [18F]AlF-OC ("incremental lesions"). METHODS: Ten patients with a histologically confirmed neuroendocrine tumor (NET) and a standard-of-care [68Ga]Ga-DOTATATE PET/CT, performed within 3 months, were prospectively included. Patients underwent a whole-body PET/MRI (TOF, 3 T, GE Signa), 2 hours after IV injection of 4 MBq/kg [18F]AlF-OC. Positive PET lesions were evaluated for a corresponding lesion on MRI. The diagnostic performance of both PET tracers was evaluated by determining the detection ratio (DR) for each scan and the differential detection ratio (DDR) per patient. RESULTS: In total, 195 unique lesions were detected: 167 with [68Ga]Ga-DOTATATE and 193 with [18F]AlF-OC. The DR for [18F]AlF-OC was 99.1% versus 91.4% for [68Ga]Ga-DOTATATE, significant for non-inferiority testing (p = 0.0001). Out of these 193 [18F]AlF-OC lesions, 96.2% were confirmed by MRI to be NET lesions. Thirty-three incremental lesions were identified by [18F]AlF-OC, of which 91% were confirmed by MRI and considered true positives. CONCLUSION: The DR of [18F]AlF-OC was numerically higher and non-inferior to the DR of [68Ga]Ga-DOTATATE. [18F]AlF-OC lesions and especially incremental lesions were confirmed as true positives by MRI in more than 90% of lesions. Taken together, these data further validate [18F]AlF-OC as a new alternative for SSTR PET in clinical practice. Trial registration ClinicalTrials.gov: NCT04552847. Registered 17 September 2020, https://beta. CLINICALTRIALS: gov/study/NCT04552847.

New Developments in Treating RAS-Mutated Metastatic Colorectal Cancer.

OPINION STATEMENT: One of the great challenges in digestive oncology is choosing the optimal therapy for RAS-mutated metastatic colorectal cancer (mCRC). Even though the RAS genes and accompanying pathway were identified decades ago and extensive knowledge exists on their role in carcinogenesis, it has proven challenging to translate these insights into new therapies and clinical benefit for patients. However, recently, new drugs targeting this pathway (for example, KRASG12C inhibitors) have shown promising results in clinical trials, as monotherapy or in combination regimens. Although resistance remains an important issue, more knowledge on adaptive resistance and feedback loops in the RAS-pathway has led to strategical combination regimens to overcome this problem. In the past year, many encouraging results have been published or presented at conferences. Even though some of the data is still preliminary, these studies may bring practice-changing results and can lead to a clinical benefit for patients over the coming years. Because of these recent developments, the treatment of RAS-mutated mCRC has become a topic of great interest. Therefore, in this review, we will summarize the standard of care and discuss the most important emerging therapies for this patient population.

The Role of Immunotherapy in Esophageal and Gastric Cancer.

Upper gastrointestinal tract tumors historically have a poor prognosis. The decision to treat esophageal or gastric cancers by surgery, radiotherapy, systemic therapy, or a combination of these treatment modalities should always be discussed multidisciplinary. The introduction of immunotherapy has drastically transformed the treatment landscape of multiple solid malignancies. Emerging data from early and late phase clinical trials suggests that the use of immunotherapies that target immune checkpoint proteins such as PD-1/PD-L1 result in superior overall survival in advanced, metastatic, or recurrent esophageal and gastric cancer, whether or not with specific molecular characteristics such as PD-L1 expression level or microsatellite instability. This review offers an overview of the most recent advances in the field of immunotherapy treatment in esophageal and gastric cancer.

Humoral and Cellular Immune Responses against SARS-CoV-2 after Third Dose BNT162b2 following Double-Dose Vaccination with BNT162b2 versus ChAdOx1 in Patients with Cancer.

PURPOSE: Patients with cancer display reduced humoral responses after double-dose COVID-19 vaccination, whereas their cellular response is more comparable with that in healthy individuals. Recent studies demonstrated that a third vaccination dose boosts these immune responses, both in healthy people and patients with cancer. Because of the availability of many different COVID-19 vaccines, many people have been boosted with a different vaccine from the one used for double-dose vaccination. Data on such alternative vaccination schedules are scarce. This prospective study compares a third dose of BNT162b2 after double-dose BNT162b2 (homologous) versus ChAdOx1 (heterologous) vaccination in patients with cancer. EXPERIMENTAL DESIGN: A total of 442 subjects (315 patients and 127 healthy) received a third dose of BNT162b2 (230 homologous vs. 212 heterologous). Vaccine-induced adverse events (AE) were captured up to 7 days after vaccination. Humoral immunity was assessed by SARS-CoV-2 anti-S1 IgG antibody levels and SARS-CoV-2 50% neutralization titers (NT50) against Wuhan and BA.1 Omicron strains. Cellular immunity was examined by analyzing CD4+ and CD8+ T-cell responses against SARS-CoV-2-specific S1 and S2 peptides. RESULTS: Local AEs were more common after heterologous boosting. SARS-CoV-2 anti-S1 IgG antibody levels did not differ significantly between homologous and heterologous boosted subjects [GMT 1,755.90 BAU/mL (95% CI, 1,276.95-2,414.48) vs. 1,495.82 BAU/mL (95% CI, 1,131.48-1,977.46)]. However, homologous-boosted subjects show significantly higher NT50 values against BA.1 Omicron. Subjects receiving heterologous boosting demonstrated increased spike-specific CD8+ T cells, including higher IFNγ and TNFα levels. CONCLUSIONS: In patients with cancer who received double-dose ChAdOx1, a third heterologous dose of BNT162b2 was able to close the gap in antibody response.

18F-AlF-NOTA-Octreotide Outperforms 68Ga-DOTATATE/NOC PET in Neuroendocrine Tumor Patients: Results from a Prospective, Multicenter Study.

18F-labeled somatostatin analogs (SSAs) could represent a valid alternative to the current gold standard, 68Ga-labeled SSAs, for somatostatin receptor imaging in patients with neuroendocrine tumors (NETs), given their logistic advantages. Recently, 18F-AlF-NOTA-octreotide (18F-AlF-OC) has emerged as a promising candidate, but a thorough comparison with 68Ga-DOTA-SSA in large patient groups is needed. This prospective, multicenter trial aims to demonstrate noninferiority of 18F-AlF-OC compared with 68Ga-DOTA-SSA PET in NET patients (ClinicalTrials.gov, NCT04552847). Methods: Seventy-five patients with histologically confirmed NET and routine clinical 68Ga-DOTATATE (n = 56) or 68Ga-DOTANOC (n = 19) PET, performed within a 3-mo interval of the study scan (median, 7 d; range, -30 to +32 d), were included. Patients underwent a whole-body PET 2 h after intravenous injection of 4 MBq/kg of 18F-AlF-OC. A randomized, masked consensus read was performed by 2 experienced readers to count tumor lesions. After unmasking, the detection ratio (DR) was determined for each scan, that is, the fraction of lesions detected on a scan compared with the union of lesions of both scans. The differential DR (DDR; difference in DR between 18F-AlF-OC and 68Ga-DOTATATE/NOC) per patient was calculated. Tracer uptake was evaluated by comparing SUVmax and tumor-to-background ratios in concordant lesions. Results: In total, 4,709 different tumor lesions were detected: 3,454 with 68Ga-DOTATATE/NOC and 4,278 with 18F-AlF-OC. The mean DR with 18F-AlF-OC was significantly higher than with 68Ga-DOTATATE/NOC (91.1% vs. 75.3%; P < 10-5). The resulting mean DDR was 15.8%, with a lower margin of the 95% CI (95% CI, 9.6%-22.0%) higher than -15%, which is the prespecified boundary for noninferiority. The mean DDRs for the 68Ga-DOTATATE and 68Ga-DOTANOC subgroups were 11.8% (95% CI, 4.3-19.3) and 27.5% (95% CI, 17.8-37.1), respectively. The mean DDR for most organs was higher than zero, except for bone lesions (mean DDR, -2.8%; 95% CI, -17.8 to 12.2). No significant differences in mean SUVmax were observed (P = 0.067), but mean tumor-to-background ratio was significantly higher with 18F-AlF-OC than with 68Ga-DOTATATE/NOC (31.7 ± 36.5 vs. 25.1 ± 32.7; P = 0.001). Conclusion: 18F-AlF-OC is noninferior and even superior to 68Ga-DOTATATE/NOC PET in NET patients. This validates 18F-AlF-OC as an option for clinical practice somatostatin receptor PET.

Prognostic implications of cellular senescence in resected non-small cell lung cancer.

Background: Cure and long-term survival for non-small cell lung cancer (NSCLC) remains hard to achieve. Cellular senescence, an emerging hallmark of cancer, is considered as an endogenous tumor suppressor mechanism. However, senescent cancer cells can paradoxically affect the surrounding tumor microenvironment (TME), ultimately leading to cancer relapse and metastasis. As such, the role of cellular senescence in cancer is highly controversial. Methods: In 155 formalin-fixed paraffin-embedded (FFPE) samples from surgically resected NSCLC patients with pathological tumor-node-metastasis (pTNM) stages I-IV (8th edition), cellular senescence was assessed using a combination of four immunohistochemical senescence markers, i.e., lipofuscin, p16INK4a, p21WAF1/Cip1 and Ki67, and correlated to clinicopathological parameters and outcomes, including overall survival (OS) and disease-free survival (DFS). Results: A tumoral senescence signature (SS) was present in 48 out of 155 NSCLC patients, but did not correlate to any clinicopathological parameter, except for p53 mutation status. In a histologically homogenous patient cohort of 100 patients who fulfilled the following criteria: (I) one type of histology, i.e., adenocarcinoma, (II) without known epidermal growth factor receptor (EGFR) mutation, (III) curative (R0) resection and (IV) no neoadjuvant systemic therapy or radiotherapy, the median OS and DFS for patients with a tumoral SS (n=30, 30.0%) compared to patients without a tumoral SS (n=70, 70.0%) was 53 versus 141 months (P=0.005) and 45 versus 55 months (P=0.25), respectively. In multiple Cox proportional hazards (Cox PH) model analysis correcting for age, pTNM stage I-III and adjuvant therapy, a tumoral SS remained a significant prognostic factor for OS (HR =2.03; P=0.014). Conclusions: The presence of a tumoral SS particularly based on high p16INK4a expression significantly affects OS in NSCLC adenocarcinoma. In this light, adjuvant senolytic therapy could be an interesting strategy for NSCLC patients harboring a tumoral SS, ultimately to improve survival of these patients.

False positive Herpes Simplex IgM serology in COVID-19 patients correlates with SARS-CoV-2 IgM/IgG seropositivity.

Differentiating COVID-19 from other causes of viral pneumonia, like herpes simplex (HSV), can be complicated by shared clinical and laboratory features. Viral pneumonia is mostly diagnosed based on molecular or serological techniques. Serological immunoassay interferences, often attributed to concurrent appearance of heterologous (viral) immunoglobulins, is well-known, but has not been studied in COVID-19 patients. Following false positive HSV immunoglobulin M (IgM) results in our index patient, 25 other COVID-19 patients were tested for HSV-1/2 IgM with the chemiluminescent Liaison assay and Euroimmun enzyme-linked immunosorbent assay. Forty-five percent of COVID-19 patients tested positive for HSV IgM with Liaison. No HSV indices were positive with Euroimmun enzyme-linked immunosorbent assay, suggesting immunoassay interference. Significant correlation between HSV IgM and SARS-CoV-2 IgM/IgG positivity was found. Adding 0.5% polyvinylpyrrolidone, inhibiting non-specific solid-phase adsorption, abolished interference in 22% of false positive cases, suggesting interference caused by solid-phase reactive IgM. Hence, serologic immunoassay results should be interpreted with caution in COVID-19 patients.

Quality of pathology reporting and adherence to guidelines in rectal neuroendocrine neoplasms: a Belgian national study.

The incidence of neuroendocrine neoplasms (NEN) in the rectum is rising since the introduction of colonoscopy screening programs. Guidelines, such as the European NeuroEndocrine Tumor Society (ENETS) algorithm, are mainly based on expert opinion. The goal of this nationwide study is to gain a better insight into the evolution in pathology reporting and adherence to the ENETS guidelines in Belgium. In Belgium, all NENs have to be reported to the Belgian Cancer Registry. We thoroughly reviewed all available pathology reports, coded as rectal NEN between 2004 and 2015, and reclassified according to World Health Organisation (WHO) classification 2019. To evaluate the adherence to the ENETS guidelines, population-based cancer registry data were linked with the medical procedures of the Belgian Health Insurance database. A total of 670 rectal NEN were retained and 16% of the cases needed reclassification. Annual incidence between 2004 and 2015 tripled from 0,20 to 0,61 per 100.000 inhabitants. Reporting of Ki67 proliferation index ameliorated most, while reporting of tumor size, lymphovascular and perineural invasion remained disappointing. Endoscopic ultrasound was performed in only 36.6% of the cases, while the mostly recommended mode of treatment (endoscopic/surgical/no resection) was followed in the majority of the cases. Incidence of rectal NEN in Belgium increased throughout the years and quality of pathology reporting improved especially after the WHO classification update in 2010. The growing awareness and knowledge among clinicians and pathologists in the community counters the need for centralization.

Longitudinal Copy-Number Alteration Analysis in Plasma Cell-Free DNA of Neuroendocrine Neoplasms is a Novel Specific Biomarker for Diagnosis, Prognosis, and Follow-up.

PURPOSE: As noninvasive biomarkers are an important unmet need for neuroendocrine neoplasms (NEN), biomarker potential of genome-wide molecular profiling of plasma cell-free DNA (cfDNA) was prospectively studied in patients with NEN. EXPERIMENTAL DESIGN: Longitudinal plasma samples were collected from patients with well-differentiated, metastatic gastroenteropancreatic and lung NEN. cfDNA was subjected to shallow whole-genome sequencing to detect genome-wide copy-number alterations (CNA) and estimate circulating tumor DNA (ctDNA) fraction, and correlated to clinicopathologic and survival data. To differentiate pancreatic NENs (PNEN) from pancreatic adenocarcinomas (PAAD) using liquid biopsies, a classification model was trained using tissue-based CNAs and validated in cfDNA. RESULTS: One hundred and ninety-five cfDNA samples from 43 patients with NEN were compared with healthy control cfDNA (N = 100). Plasma samples from patients with PNEN (N = 21) were used for comparison with publicly available PNEN tissue (N = 98), PAAD tissue (N = 109), and PAAD cfDNA (N = 96). Thirty percent of the NEN cfDNA samples contained ctDNA and 44% of the patients had at least one ctDNA-positive (ctDNA+) sample. CNAs detected in cfDNA were highly specific for NENs and the classification model could distinguish PAAD and PNEN cfDNA samples with a sensitivity, specificity, and AUC of 62%, 86%, and 79%, respectively. ctDNA-positivity was associated with higher World Health Organization (WHO) grade, primary tumor location, and higher chromogranin A and neuron-specific enolase values. Overall survival was significantly worse for ctDNA+ patients and increased ctDNA fractions were associated with poorer progression-free survival. CONCLUSIONS: Sequential genome-wide profiling of plasma cfDNA is a novel, noninvasive biomarker with high specificity for diagnosis, prognosis, and follow-up in metastatic NENs.

Predictive model for BNT162b2 vaccine response in cancer patients based on blood cytokines and growth factors.

Background: Patients with cancer, especially hematological cancer, are at increased risk for breakthrough COVID-19 infection. So far, a predictive biomarker that can assess compromised vaccine-induced anti-SARS-CoV-2 immunity in cancer patients has not been proposed. Methods: We employed machine learning approaches to identify a biomarker signature based on blood cytokines, chemokines, and immune- and non-immune-related growth factors linked to vaccine immunogenicity in 199 cancer patients receiving the BNT162b2 vaccine. Results: C-reactive protein (general marker of inflammation), interleukin (IL)-15 (a pro-inflammatory cytokine), IL-18 (interferon-gamma inducing factor), and placental growth factor (an angiogenic cytokine) correctly classified patients with a diminished vaccine response assessed at day 49 with >80% accuracy. Amongst these, CRP showed the highest predictive value for poor response to vaccine administration. Importantly, this unique signature of vaccine response was present at different studied timepoints both before and after vaccination and was not majorly affected by different anti-cancer treatments. Conclusion: We propose a blood-based signature of cytokines and growth factors that can be employed in identifying cancer patients at persistent high risk of COVID-19 despite vaccination with BNT162b2. Our data also suggest that such a signature may reflect the inherent immunological constitution of some cancer patients who are refractive to immunotherapy.

Cancer-Associated Fibroblasts as a Common Orchestrator of Therapy Resistance in Lung and Pancreatic Cancer.

Cancer arises from mutations accruing within cancer cells, but the tumor microenvironment (TME) is believed to be a major, often neglected, factor involved in therapy resistance and disease progression. Cancer-associated fibroblasts (CAFs) are prominent and key components of the TME in most types of solid tumors. Extensive research over the past decade revealed their ability to modulate cancer metastasis, angiogenesis, tumor mechanics, immunosuppression, and drug access through synthesis and remodeling of the extracellular matrix and production of growth factors. Thus, they are considered to impede the response to current clinical cancer therapies. Therefore, targeting CAFs to counteract these protumorigenic effects, and overcome the resistance to current therapeutic options, is an appealing and emerging strategy. In this review, we discuss how CAFs affect prognosis and response to clinical therapy and provide an overview of novel therapies involving CAF-targeting agents in lung and pancreatic cancer.

PDX1 DNA Methylation Distinguishes Two Subtypes of Pancreatic Neuroendocrine Neoplasms with a Different Prognosis.

DNA methylation is a crucial epigenetic mechanism for gene expression regulation and cell differentiation. Furthermore, it was found to play a major role in multiple pathological processes, including cancer. In pancreatic neuroendocrine neoplasms (PNENs), epigenetic deregulation is also considered to be of significance, as the most frequently mutated genes have an important function in epigenetic regulation. However, the exact changes in DNA methylation between PNENs and the endocrine cells of the pancreas, their likely cell-of-origin, remain largely unknown. Recently, two subtypes of PNENs have been described which were linked to cell-of-origin and have a different prognosis. A difference in the expression of the transcription factor PDX1 was one of the key molecular differences. In this study, we performed an exploratory genome-wide DNA methylation analysis using Infinium Methylation EPIC arrays (Illumina) on 26 PNENs and pancreatic islets of five healthy donors. In addition, the methylation profile of the PDX1 region was used to perform subtyping in a global cohort of 83 PNEN, 2 healthy alpha cell and 3 healthy beta cell samples. In our exploratory analysis, we identified 26,759 differentially methylated CpGs and 79 differentially methylated regions. The gene set enrichment analysis highlighted several interesting pathways targeted by altered DNA methylation, including MAPK, platelet-related and immune system-related pathways. Using the PDX1 methylation in 83 PNEN, 2 healthy alpha cell and 3 healthy beta cell samples, two subtypes were identified, subtypes A and B, which were similar to alpha and beta cells, respectively. These subtypes had different clinicopathological characteristics, a different pattern of chromosomal alterations and a different prognosis, with subtype A having a significantly worse prognosis compared with subtype B (HR 0.22 [95% CI: 0.051-0.95], p = 0.043). Hence, this study demonstrates that several cancer-related pathways are differently methylated between PNENs and normal islet cells. In addition, we validated the use of the PDX1 methylation status for the subtyping of PNENs and its prognostic importance.

Clinical applications of (epi)genetics in gastroenteropancreatic neuroendocrine neoplasms: Moving towards liquid biopsies.

High-throughput analysis, including next-generation sequencing and microarrays, have strongly improved our understanding of cancer biology. However, genomic data on rare cancer types, such as neuroendocrine neoplasms, has been lagging behind. Neuroendocrine neoplasms (NENs) develop from endocrine cells spread throughout the body and are highly heterogeneous in biological behavior. In this challenging disease, there is an urgent need for new therapies and new diagnostic, prognostic, follow-up and predictive biomarkers to aid patient management. The last decade, molecular data on neuroendocrine neoplasms of the gastrointestinal tract and pancreas, termed gastroenteropancreatic NENs (GEP-NENs), has strongly expanded. The aim of this review is to give an overview of the recent advances on (epi)genetic level and highlight their clinical applications to address the current needs in GEP-NENs. We illustrate how molecular alterations can be and are being used as therapeutic targets, how mutations in DAXX/ATRX and copy number variations could be used as prognostic biomarkers, how far we are in identifying predictive biomarkers and how genetics can contribute to GEP-NEN classification. Finally, we discuss recent studies on liquid biopsies in the field of GEP-NENs and illustrate how liquid biopsies can play a role in patient management. In conclusion, molecular studies have suggested multiple potential biomarkers, but further validation is ongoing.