Belgian guidelines for pathology reporting of neuroendocrine neoplasms of the pancreaticobiliary and gastrointestinal tract.

Since neuroendocrine neoplasms are rare tumors, registration of patient data in national and multinational registries is recommended. Indeed, this will facilitate multicenter studies on the epidemiology, efficacy and safety of diagnostic and therapeutic strategies for well-differentiated neuroendocrine tumors as well as for neuroendocrine carcinomas. In Belgium, data on patient and tumor characteristics of all newly diagnosed malignancies have been collected in the Belgian Cancer Registry since 2004 including anonymized full pathological reports. The Digestive Neuroendocrine Tumor (DNET) registry collects information on classification, staging, diagnostic tools and treatment in a prospective national online database. However, the terminology, classification and staging systems of neuroendocrine neoplasms have changed repeatedly over the past 20 years as a result of a better understanding of these rare tumors, by joining forces internationally. These frequent changes make it very difficult to exchange data or perform retrospective analyses. For optimal decision making, for a clear understanding and to allow reclassification according to the latest staging system, several items need to be described in the pathology report. This paper provides an overview of the essential items in reporting neuroendocrine neoplasms of the pancreaticobiliary and gastrointestinal tract.

Gastric MALT-Lymphoma: more than Helicobacter Pylori.

In this case report, we describe two cases of gastric mucosaassociated lymphoid tissue (MALT) lymphoma. The first patient, who presented with complaints of indigestion, nausea and epigastralgy, had a solid ulcer on endoscopy. Biopsies showed, next to MALT, presence of Helicobacter Pylori. The second patient was admitted with hematemesis. The multiple ulcerations in his stomach were thought to be cocaine-induced. Only after multiple biopsies the diagnosis of MALT was made. No presence of Helicobacter Pylori could be detected. The first patient was successfully treated with Helicobacter Pylori eradication therapy. Localized radiotherapy resulted in complete remission in our second patient. Hence, in absence of Helicobacter Pylori, more aggressive treatment modalities are needed.

Lessons learned about appendiceal neuroendocrine neoplasms from data analysis of the Belgian Cancer Registry 2010-2015.

BACKGROUND AND STUDY AIMS: Appendiceal neuroendocrine neo-plasms (aNENs) are a diverse group of malignant neoplasms of varying biological behavior for which information about manage-ment and outcome is sparse, with the majority of available studies being retrospective, including only a limited number of patients, and therefore not necessarily reflecting the reality in the community. In the present study clinical, epidemiological and pathological data of appendiceal neuroendocrine neoplasms in Belgium is provided and compared with current literature. METHODS: A population-based study was conducted by linking data of the Belgian Cancer Registry with medical procedures in the Belgian Health Insurance database for patients diagnosed with aNEN between 2010 and 2015. RESULTS: We found an aNEN incidence of 0.97/100.000 person years in Belgium. Neuroendocrine carcinoma of the appendix are rare. Most appendiceal neuroendocrine tumors (aNETs) are small G1 tumors. Positive lymph nodes are often found in tumors larger than 2cm, especially aNET G2. CONCLUSION: A rapid uptake of changing classifications was seen in the community. However, systematic reporting of risk factors for small aNEN can still be improved and should be stimulated. In 9% of cases, reclassifications had to be made, pointing out that in a retrospective analysis, original pathological reports should be checked for specific parameters, before reliable conclusions can be drawn.

Reduced humoral immune response after BNT162b2 coronavirus disease 2019 messenger RNA vaccination in cancer patients under antineoplastic treatment.

BACKGROUND: Cancer patients are at a higher risk of developing severe coronavirus disease 2019 (COVID-19). However, the safety and efficacy of COVID-19 vaccination in cancer patients undergoing treatment remain unclear. PATIENTS AND METHODS: In this interventional prospective multicohort study, priming and booster doses of the BNT162b2 COVID-19 vaccine were administered 21 days apart to solid tumor patients receiving chemotherapy, immunotherapy, targeted or hormonal therapy, and patients with a hematologic malignancy receiving rituximab or after allogeneic hematopoietic stem cell transplantation. Vaccine safety and efficacy (until 3 months post-booster) were assessed. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor-binding domain (RBD) antibody levels were followed over time (until 28 days after the booster) and in vitro SARS-CoV-2 50% neutralization titers (NT50) toward the wild-type Wuhan strain were analyzed 28 days after the booster. RESULTS: Local and systemic adverse events (AEs) were mostly mild to moderate (only 1%-3% of patients experienced severe AEs). Local, but not systemic, AEs occurred more frequently after the booster dose. Twenty-eight days after the booster vaccination of 197 cancer patients, RBD-binding antibody titers and NT50 were lower in the chemotherapy group {234.05 IU/ml [95% confidence interval (CI) 122.10-448.66] and 24.54 (95% CI 14.50-41.52), respectively} compared with healthy individuals [1844.93 IU/ml (95% CI 1383.57-2460.14) and 122.63 (95% CI 76.85-195.67), respectively], irrespective of timing of vaccination during chemotherapy cycles. Extremely low antibody responses were seen in hematology patients receiving rituximab; only two patients had RBD-binding antibody titers necessary for 50% protection against symptomatic SARS-CoV-2 infection (<200 IU/ml) and only one had NT50 above the limit of detection. During the study period, five cancer patients tested positive for SARS-CoV-2 infection, including a case of severe COVID-19 in a patient receiving rituximab, resulting in a 2-week hospital admission. CONCLUSION: The BNT162b2 vaccine is well-tolerated in cancer patients under active treatment. However, the antibody response of immunized cancer patients was delayed and diminished, mainly in patients receiving chemotherapy or rituximab, resulting in breakthrough infections.

The effect of pectin on swelling and permeability characteristics of free films containing Eudragit RL and/or RS as a coating formulation aimed for colonic drug delivery.

BACKGROUND AND THE PURPOSE OF THE STUDY: The potential of pectin as a bacterially degradable polysaccharide for colon drug delivery has been demonstrated. Due to the high solubility and swelling properties of pectin in aqueous media, it is frequently used in combination with water insoluble polymers for targeting drugs to the colon. The aim of this study was to evaluate free films containing pectin as a bacterially-degradable polysaccharide in combination with Eudragit RL (ERL) and/or RS (ERS) as a coating formulation for colonic drug delivery. METHODS: Isolated free films comprising 20% pectin and 80% ERL or ERS and their combination in 1:1 ratio were prepared by casting method. Then, free films were evaluated by water vapor transmission (WVT), swelling and permeability experiments for theophylline and indomethacin in different media. RESULTS: Formulations containing ERL exhibited higher WVT, swelling and permeability compared with formulations containing ERS. The permeability of theophylline through free films composed of pectin and eudragit polymers in simulated colonic media was not significantly different from those obtained in other media. However indomethacin free films containing pectin and ERL showed higher permeation in simulated colonic fluid (SCF) compared to the other media. MAJOR CONCLUSION: Formulation containing pectin and ERL may be suitable as a coating formulation for colon targeted delivery of drugs of low solubility such as indomethacin.

Current practice in approaching controversial diagnostic and therapeutic topics in gastroenteropancreatic neuroendocrine neoplasm management. Belgian multidisciplinary expert discussion based on a modified Delphi method.

BACKGROUND AND STUDY AIMS: Neuroendocrine neoplasms (NENs) are relatively rare, with marked clinical and biological heterogeneity. Consequently, many controversial areas remain in diagnosis and optimal treatment stratification for NEN patients. We wanted to describe current clinical practice regarding controversial NEN topics and stimulate critical thinking and mutual learning among a Belgian multidisciplinary expert panel. PATIENTS AND METHODS: A 3-round, Delphi method based project, coordinated by a steering committee (SC), was applied to a predefined multidisciplinary NEN expert panel studying the following controversial topics : factors guiding therapeutic decision making, the use of somatostatin analogues (SSA) in adjuvant setting, the interference between non-radioactive and radioactive SSAs, challenging small intestine neuroendocrine tumor (NET) cases, the approach of the carcinoid syndrome, the role of chemotherapy in well differentiated NET, the relevance of NET G3 and neuroendocrine carcinoma subclassification and the role of imaging techniques in NEN management. RESULTS: A high level of consensus exists regarding the necessary diagnostic work-up, use of imaging techniques and interference between non-radioactive and radioactive SSAs. However, the prognostic impact of tumor functionality might be overrated and adequate diarrhea differential diagnostic work-up in these patients is underused. Significant differences are seen between individual experts and centers regarding treatment preferences both on the treatment modality level, as well as the choice of specific drugs (e.g. chemotherapy regimen). CONCLUSIONS: A Delphi-like multi-round expert discussion proves useful to boost critical thinking and discussion among experts of different background, as well as to describe current clinical practice and stimulate mutual learning in the absence of high-level scientific guidance.

Hotspot DAXX, PTCH2 and CYFIP2 mutations in pancreatic neuroendocrine neoplasms.

Mutations in DAXX/ATRX, MEN1 and genes involved in the phosphoinositide-3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway have been implicated in pancreatic neuroendocrine neoplasms (pNENs). However, mainly mutations present in the majority of tumor cells have been identified, while proliferation-driving mutations could be present only in small fractions of the tumor. This study aims to identify high- and low-abundance mutations in pNENs using ultra-deep targeted resequencing. Formalin-fixed paraffin-embedded matched tumor-normal tissue of 38 well-differentiated pNENs was sequenced using a HaloPlex targeted resequencing panel. Novel amplicon-based algorithms were used to identify both single nucleotide variants (SNVs) and insertion-deletions (indels) present in >10% of reads (high abundance) and in <10% of reads (low abundance). Found variants were validated by Sanger sequencing. Sequencing resulted in 416,711,794 reads with an average target base coverage of 2663 ± 1476. Across all samples, 32 high-abundance somatic, 3 germline and 30 low-abundance mutations were withheld after filtering and validation. Overall, 92% of high-abundance and 84% of low-abundance mutations were predicted to be protein damaging. Frequently, mutated genes were MEN1, DAXX, ATRX, TSC2, PI3K/Akt/mTOR and MAPK-ERK pathway-related genes. Additionally, recurrent alterations on the same genomic position, so-called hotspot mutations, were found in DAXX, PTCH2 and CYFIP2. This first ultra-deep sequencing study highlighted genetic intra-tumor heterogeneity in pNEN, by the presence of low-abundance mutations. The importance of the ATRX/DAXX pathway was confirmed by the first-ever pNEN-specific protein-damaging hotspot mutation in DAXX. In this study, both novel genes, including the pro-apoptotic CYFIP2 gene and hedgehog signaling PTCH2, and novel pathways, such as the MAPK-ERK pathway, were implicated in pNEN.

Transport of quercetin di-sodium salt in the human intestinal epithelial Caco-2 cell monolayer 139.

Quercetin di-sodium salt (QDS), a water-soluble derivative of quercetin (Q), is a potent free radical scavenger. The aim of this study was to examine the in vitro intestinal transport of QDS compared to that of Q using the Caco-2 human intestinal epithelial cell line. The apical (A) to basolateral (B) transport of QDS was found to be higher than the B to A transport of this compound. This polarized transport involved the presence of a carrier protein system. The involvement of the sodium/glucose transporter-1 (SGLT-1) was shown by using phloridzin, a selective inhibitor of this conveyor system. However, the transport of Q was not affected by this inhibitor. Moreover, the influx of QDS was pH-sensitive and decreased at pH 5.5 compared with that observed at pH 7.4 and 6.5. The permeability of QDS was 10-fold higher than that of Q. This could be explained by the involvement of SLGT-1 and the absence of an active efflux pump in the absorption of QDS in comparison with Q. This finding was supported by comparing the solubility of Q with that of QDS. This study indicates that both the higher solubility of QDS and its dependence on the SGLT-1 transport system resulted in more efficient permeability compared to Q.

Permeability and swelling studies on free films containing inulin in combination with different polymethacrylates aimed for colonic drug delivery.

The aim of this study was to assess some permeability and swelling characteristics of free films prepared by combination of inulin as a bacterially degradable system and time- or pH-dependent polymers as a coating formulation for colonic drug delivery. Different free films were prepared by casting and solvent evaporation method. Formulations containing inulin with Eudragit RS, Eudragit RL, Eudragit RS-Eudragit RL, Eudragit FS and Eudragit RS-Eudragit S with different ratios of inulin were prepared. After preparation, free films were evaluated by water vapor transmission test, swelling experiment and permeability to indomethacin and theophylline in different media. Formulations containing Eudragit FS had high resistance to water vapor permeation; but were unable to protect premature swelling and drug release in simulated small intestine media. Also, combination of Eudragit RS and Eudragit S had no suitable characteristics for colon delivery. However, Eudragit RS and Eudragit RL in combination with inulin made free films which had more swelling and permeation of drug in the colonic medium rather than the other media. It was shown that formulations containing sustained release polymethacrylates in combination with inulin have more potential as a coating system for specific colon delivery compared with pH-dependent polymers.

Physico-mechanical properties of poly (epsilon-caprolactone) for the construction of rumino-reticulum devices for grazing animals.

The solid-state degradation of poly(epsilon-caprolactone) in the rumen of fistulated cattle was investigated. The degradation process was studied by measurement of changes in weight loss, crystallinity, Young's modulus, molecular weight by size exclusion chromatography and by intrinsic viscosity. In vitro degradation studies were conducted at 39 degrees C in aqueous solutions with a pH and ionic strength as near as possible to those encountered in vivo. Such studies demonstrated that the poly (epsilon-caprolactone) degraded more rapidly in vivo than in vitro. In vivo, chain scission is associated with an increase in crystallinity. The faster degradation in vivo was attributed to fatty acids and bacteria that are present in the rumen, the first portion of the stomach of the grazing animals.

Quantitation of levamisole in plasma using high performance liquid chromatography.

A rapid and sensitive procedure is described for the quantitation of levamisole in plasma using high-performance liquid chromatography (HPLC). The procedure involves sample preparation using a reverse-phase C18 cartridge prior to chromatography and quantitation using peak area ratios (UV absorbance detection, 225 nm) of levamisole to the internal standard, quinine. The limit of detection was 21 ng/ml and the limit of quantification was 72 ng/ml, both contained in 1 ml of plasma. The recoveries were sufficiently high (73.1%) and overall coefficient of variation of the procedure was 0.25%. This procedure has been used to determine levamisole levels in human and cattle plasma. A comparison of using two C18 columns (Nova-pak, Puresil) was also studied and discussed.

Niosomes as carriers of radiopaque contrast agents for X-ray imaging.

Non-ionic surfactant vesicles (niosomes) are considered as carriers of iobitridol, a diagnostic agent used for X-ray imaging. The niosomes, with a diameter between 150 and 175 nm, are prepared using the film-hydration method followed by sonication. These vesicles were obtained with appropriate mixtures of D-alpha tocopheryl polyethylene glycol 1000 succinate, polyoxyethylene glycol 4000 stearate, sorbitan monostearate, cholesterol and dicetylphosphate. Methods allowing the increase of the rate of encapsulation and the stability of the vesicles were carried out. In addition to the study of the formulation of the vesicles, the physico-chemical and morphological properties of the vesicles have been studied.