Plasma chromogranin A in patients with autoimmune chronic atrophic gastritis, enterochromaffin-like cell lesions and gastric carcinoids

Factors influencing blood tumor marker concentrations in the absence of neoplasia

BACKGROUND

Tumor markers (TMs) are a heterogeneous group of molecules used in the diagnosis, prognosis and follow-up of cancer patients. During neoplastic differentiation, cells can either directly synthesize or induce the synthesis of TMs, and the release of these molecules into the bloodstream allows their quantification in biological fluids. Although very small concentrations of TMs are usually present in the serum or plasma of healthy subjects, increased concentrations may also be found in the presence of benign diseases or due to technical interference, producing false positive results.

MATERIAL AND METHODS AND RESULTS

Our review analyses the causes of false positives described between January 1970 to February 2023 for the TMs most frequently used in clinical practice: α-fetoprotein (AFP), β2-microglobulin (β2-M), cancer antigen 15-3 (CA 15-3), cancer antigen CA 19-9 (CA 19-9), cancer antigen CA 72-4 (CA 72-4), cancer antigen 125 (CA 125), carcinoembryonic antigen (CEA), chromogranin A (CgA), choriogonadotropin (hCG), cytokeratin 19 fragment (CYFRA 21-1), neuron-specific enolase (NSE), human epididymis protein 4 (HE4), serum HER2 (sHER2), squamous cell carcinoma antigen (SCCA), protein induced by vitamin K absence-II (PIVKA-II), Pro-gastrin-releasing peptide (Pro-GRP), prostate-specific antigen (PSA), Protein S-100 (S-100) and thyroglobulin (Tg). A total of 247 references were included.

CONCLUSIONS

A better understanding of pathophysiological processes and other conditions that affect the concentration of TMs might improve the interpretation of results and their clinical application.

Rat Experimental Autoimmune Gastritis Model

BACKGROUND

Autoimmune gastritis (AIG) is an autoimmune disease of the stomach characterized by the destruction of the oxyntic mucosa, which stops producing acid and becomes both functionally and morphologically atrophic. The pathogenic mechanisms behind the disease are still poorly understood. There is no early diagnosis and specific AIG therapy. To elucidate the pathogenesis of AIG, to search for early diagnostic markers, as well as to test new therapeutic approaches, an adequate and easily reproducible experimental model for autoimmune gastritis (EAG) is needed. Existing EAG models have some limitations, including slow development of signs, absence of advanced gastritis, irrational use of animals to obtain antigen. The aim was to find out whether it is possible to cause autoimmune gastritis similar to human disease in Wistar rats through immunization with a homologous gastric mucosa extract.

METHODS

Wistar rats were immunized with gastric mucosa extract. Histology studies and evaluation of serological parameters were performed 56 and 91 days later.

RESULTS

Destruction of oxyntic glands by infiltrating T lymphocytes were detected in rats on 56 and 91 days after initial immunization with gastric mucosa extract. Hyperplasia of enterochromaffin-like (ECL) cells was detected on the 91st day. Antral mucosa remained unchanged.

CONCLUSION

Wistar rats, immunized with gastric mucosa extract, developed EAG similar to human AIG. The advantages of received EAG model are the ease of obtaining, the rapid development of oxyntic mucosa damage, which may progress to ECL cell hyperplasia.

Exploring the spectrum of incidental gastric polyps in autoimmune gastritis

BACKGROUND

Gastric polyps represent an abnormal proliferation of the gastric mucosa. Chronic atrophic autoimmune gastritis (CAAG) targets parietal cells and results in hypo-achlorhydria and hypergastrinemia, which exerts a proliferative effect on the gastric mucosa.

AIMS

We investigate the incidence of gastric polyps in CAAG patients.

METHODS

This is a single-center retrospective study examining patients with confirmed CAAG from January 1990 until June 2022. Demographic, clinical, biochemical, and serological data were collected for each included patient. The histopathological characteristics of the detected polyps were recorded.

RESULTS

A total of 176 CAAG patients were included. Eighty-nine (50.5%) had 163 incidental polyps. Seventy-six patients (85%) had 130 non-endocrine lesions, among which 118 (90.7%) were inflammatory, 6 (4.6%) adenomatous, and 4 (3%) fundic; 33 patients (37%) had gastric neuroendocrine neoplasms (gNENs), and 21 (23.6%) both; one had MALToma and one gastric adenocarcinoma. Higher circulating levels of gastrin and chromogranin A were observed among patients with polyps (median 668 vs 893 pg/ml p = 0.0237, 146 vs 207 ng/ml p = 0.0027, respectively).

CONCLUSION

CAAG implies a high incidence of gNENs and exocrine lesions. Gastrin plays a possible trophic role on the mucosa. Further evidence is needed to validate its predictive role for increased polyp risk in CAAG.

Incidence and prevalence of gastric neuroendocrine tumors in patients with chronic atrophic autoimmune gastritis

BACKGROUND

The incidence of type I gastric neuroendocrine neoplasms (gNENs) has increased significantly over the past 50 years. Although autoimmune gastritis (AIG) increases the likelihood of developing gNENs, the exact incidence and prevalence of this association remain unclear.

AIM

To evaluate the incidence and prevalence of type I gNENs in a cohort of patients with a histological diagnosis of AIG.

METHODS

Patients with a histological diagnosis of AIG were enrolled between October 2020 and May 2022. Circulating levels of CgA and gastrin were assessed at enrollment. Included patients underwent regular endoscopic follow-up to detect gastric neoplastic lesions, enterochromaffin-like (ECL) cell hyperplasia, and the development of gNEN.

RESULTS

We included 176 patients [142 women (80.7%), median age 64 years, interquartile range (IQR) 53-71 years] diagnosed with AIG between January 1990 and June 2022. At enrollment. One hundred and sixteen patients (65.9%) had ECL hyperplasia, of whom, 29.5% had simple/linear, 30.7% had micronodular, and 5.7% had macronodular type. The median follow-up time was 5 (3-7.5) years. After 1032 person-years, 33 patients developed a total of 50 type I gNENs, with an incidence rate of 0.057 person-years, corresponding to an annual cumulative incidence of 5.7%. Circulating CgA levels did not significantly differ between AIG patients who developed gNENs and those who did not. Conversely, gastrin levels were significantly higher in AIG patients who developed gNENs [median 992 pg/mL IQR = 449-1500 vs 688 pg/mL IQR = 423-1200, P = 0.03]. Calculated gastrin sensitivity and specificity were 90.9% and 1.4%, respectively, with an overall diagnostic accuracy of 30% and a calculated area under the gastrin receiver operating characteristic curve (AUROC or AUC) of 0.53.

CONCLUSION

Type I gNENs are a significant complication in AIG. Gastrin's low diagnostic accuracy prevents it from serving as a marker for early diagnosis. Effective strategies for early detection and treatment are needed.

Neuroendocrine differentiation predicts the therapeutic efficacy of abiraterone and docetaxel as first-line therapy in metastatic castration-resistant prostate cancer

PURPOSE

We aim to explore the predictive value of neuroendocrine differentiation (NED) in patients with metastatic castration-resistant prostate cancer (mCRPC) receiving abiraterone or docetaxel as first-line therapy.

METHODS

We retrospectively analyzed data of 262 mCRPC patients receiving abiraterone or docetaxel as first-line mCRPC treatment. NED was evaluated using prostate biopsy samples at the time of mCRPC by immunohistochemical staining. Kaplan-Meier curves and Cox regression were used to assess the association between NED and treatment outcomes including PSA progression-free survival (PSA-PFS), radiographic progression-free survival (rPFS), and overall survival (OS).

RESULTS

NED was confirmed in 100/262 (38.2%) mCRPC patients, with 76/100 (76.0%) and 24/100 (24.0%) men harboring NED < 10% and NED ≥ 10%, respectively. 203/262 (77.5%) and 59/262 (22.5%) patients received abiraterone and docetaxel, respectively. In abiraterone treatment, NED was associated with a significantly shorter median PSA-PFS (mPSA-PFS, 7.5 vs. 10.3-Mo, P < 0.001), median rPFS (mrPFS, 15.9 vs. 19.5-Mo, P = 0.010), and median OS (mOS, 23.2 vs. 34.3-Mo, P = 0.014)). Likewise, for mCRPC patients receiving docetaxel, the positive detection of NED also predicted shorter mPSA-PFS (3.8 vs. 5.9-Mo, P = 0.052), mrPFS (8.4 vs. 20.4-Mo, P = 0.016) and mOS (13.6 vs. 29.0-Mo, P = 0.033). The adverse prognostic trait of NED is consistent in most subgroups. Additionally, patients' survival outcomes deteriorated as the NED proportion grew in both therapies. After propensity score matching, NED-positive patients showed comparable prognosis in abiraterone and docetaxel therapy.

CONCLUSION

For mCRPC patients receiving abiraterone or docetaxel, NED and its proportion were critical predictive factors. NED detection at mCRPC might aid in predicting patients' outcomes and optimizing treatment decisions.

Chronic Autoimmune Gastritis: Modern Diagnostic Principles

This article summarizes and systematizes the available data from the literature on chronic autoimmune gastritis (CAG) in order to increase the awareness of specialists about the modern possibilities for diagnosing the disease, including its early stages. The clinical manifestation of the disease includes possible variants such as gastrointestinal, hematological (first of all, the formation of iron deficiency and B12-deficiency anemia), and neurological variants. Patients with chronic autoimmune gastritis are characterized by comorbidity with other autoimmune diseases. In this paper, data on the most informative serological markers for the diagnosis of CAG, as well as laboratory tests to detect micronutrient deficiencies, information on the characteristic changes in the gastric mucosa, and the prognosis of the disease, are presented. The diagnosis of CAG should be based on a multidisciplinary approach that combines a thorough analysis of a patient's complaints with a mandatory assessment of nutritional status, as well as the results of serological, endoscopic, and histological research methods.

Gastric neuroendocrine neoplasms: A review

Gastric neuroendocrine neoplasms (g-NENs) or neuroendocrine tumors are generally slow-growing tumors with increasing incidence. They arise from enterochromaffin like cells and are divided into four types according to clinical characteristic features. Type 1 and 2 are gastrin dependent, whereas type 3 and 4 are sporadic. The reason for hypergastrinemia is atrophic gastritis in type 1, and gastrin releasing tumor (gastrinoma) in type 2 g-NEN. The diagnosis of g-NENs needs histopathological investigation taken by upper gastrointestinal endoscopy. g-NENs are positively stained with chomogranin A and synaptophysin. Grading is made with mitotic index and ki-67 proliferation index on histopathological analysis. It is crucial to discriminate between types of g-NENs, because the management, treatment and prognosis differ significantly between subtypes. Treatment options for g-NENs include endoscopic resection, surgical resection with or without antrectomy, medical treatment with somatostatin analogues, netazepide or chemotherapy regimens. Follow-up without excision is another option in appropriate cases. The prognosis of type 1 and 2 g-NENs are good, whereas the prognosis of type 3 and 4 g-NENs are close to the prognosis of gastric adenocancer.

A Critical Appraisal of Contemporary and Novel Biomarkers in Pheochromocytomas and Adrenocortical Tumors

Simple Summary

Pheochromocytomas/paragangliomas (PPGLs) and adrenocortical tumors are neoplasms that originate from different regions of the adrenal gland and display significant heterogeneity with respect to their biological and clinical behavior. They may be sporadic or develop in the context of hereditary syndromes. Adrenocortical tumors are mostly benign but less than 2% are carcinomas associated with a poor outcome when diagnosed in advanced disease. The majority of PPGLS are benign, but a subset may develop metastatic disease. In particular, for PPGLs, it is mandatory to identify biomarkers of high sensitivity and specificity that lead to accurate diagnosis and predict patients with a malignant potential that would benefit from aggressive surveillance and administration of early treatment. Current biomarkers include mostly histopathological and genetic parameters but none of them can be considered independent predictive factors. Recent genomic studies have implemented new molecular biomarkers of high accuracy for the diagnosis and management of PPGLs and adrenocortical tumors. In this review, we summarize the current and novel biomarkers that may be considered valuable tools for diagnosis and prediction of malignancy in patients with PPGLs and adrenocortical tumors.

Abstract

Pheochromocytomas/Paragangliomas (PPGLs) and adrenocortical tumors are rare neoplasms with significant heterogeneity in their biologic and clinical behavior. Current diagnostic and predictive biomarkers include hormone secretion, as well as histopathological and genetic features. PPGL diagnosis is based on biochemical measurement of catecholamines/metanephrines, while histopathological scoring systems have been proposed to predict the risk of malignancy. Adrenocortical tumors are mostly benign, but some can be malignant. Currently, the stage of disease at diagnosis and tumor grade, appear to be the most powerful prognostic factors. However, recent genomic and proteomic studies have identified new genetic and circulating biomarkers, including genes, immunohistochemical markers and micro-RNAs that display high specificity and sensitivity as diagnostic or prognostic tools. In addition, new molecular classifications have been proposed that divide adrenal tumors in distinct subgroups with different clinical outcomes.

Chromogranin Serves as Novel Biomarker of Endocrine and Gastric Autoimmunity

CONTEXT

The glycoprotein chromogranin A (CgA) is expressed by endocrine and neuroendocrine cells. High levels of serum CgA serve as markers of neuroendocrine tumors (NET), but its role in autoimmunity has not been assessed.

OBJECTIVE

To investigate CgA utility as a marker of endocrine autoimmunity.

METHODS

CgA serum levels were evaluated in 807 consecutive unselected participants (cross-sectional study) with the time-resolved amplified cryptate emission technology.

RESULTS

Serum CgA concentrations were increased in 66%, 39%, 38%, and 24% of patients with NET, type 1 diabetes (T1D), autoimmune gastritis (AG) and autoimmune polyendocrinopathy (AP), respectively. Compared with healthy participant controls (C), the odds of positive CgA measurement were up to 28 times higher in the disease groups. In detail, the odds ratios (ORs) for positive CgA levels were 27.98, 15.22, 7.32 (all P < 0.0001) and 3.89 (P = 0.0073) in patients with NET, T1D, AG, and AP, respectively. In AG, CgA and serum gastrin correlated positively (r = 0.55; P < 0.0001). The area under the receiver operating characteristic curve to predict AG was higher for parietal cell antibody (PCA) positivity than for CgA (0.84 vs 0.67; P < 0.0001). However, in combination with PCA and intrinsic factor autoantibodies, CgA independently improved prediction of AG (OR 6.5; P = 0.031). An impact of age on CgA positivity and on CgA value was detected (P < 0.0001) while current smoking significantly increased CgA serum levels by 25% (P = 0.0080).

CONCLUSION

CgA qualifies as a novel biomarker for T1D, AP, and AG.

Serum chromogranin A level continuously rises with the progression of type 1 diabetes, and indicates the presence of both enterochromaffin-like cell hyperplasia and autoimmune gastritis

AIMS/INTRODUCTION

The relationship of chromogranin A (CgA) levels above the normal range with various outcomes, such as glycated hemoglobin levels, enterochromaffin-like cell hyperplasia and autoimmune gastritis, was investigated in type 1 diabetes patients with special regard to the progression of comorbidities.

MATERIALS AND METHODS

A cohort study on 153 type 1 diabetes patients was carried out with a prospective branch on clinical and laboratory data, and a retrospective branch on histological data obtained by gastroscopy.

RESULTS

Patients with CgA levels above the upper limit of the normal range (n = 28) had significantly higher glycated hemoglobin levels (P = 0.0160) than those with CgA in the normal range (n = 125). The correlation between CgA and glycated hemoglobin was significant (P < 0.0001), but weak (R = +0.32). A slight, but steady elevation (P = 0.0410) in CgA level was observed to co-vary with the duration of type 1 diabetes. Enterochromaffin-like cell hyperplasia and autoimmune gastritis was significantly more frequent (P = 0.0087 for both) in the high CgA group. Detailed analyses on gastric tissue samples confirmed a progression of enterochromaffin-like cell hyperplasia (P = 0.0192) accompanied by CgA elevation (P = 0.0316).

CONCLUSIONS

The early detection and follow up of the later progression of enterochromaffin-like cell hyperplasia and autoimmune gastritis into gastric neuroendocrine tumors, which have ~100-fold greater incidence in type 1 diabetes patients, can be achieved by assessment of CgA levels. Therefore, the use of CgA could be considered as a novel auxiliary biomarker in the care of these type 1 diabetes complications.

CCK2R antagonists: from SAR to clinical trials

The widespread involvement of the cholecystokinin-2/gastrin receptor (CCK₂R) in multiple (patho)physiological processes has propelled extensive searches for nonpeptide small-molecule CCK₂R antagonists. For the past three decades, considerable research has yielded numerous chemically heterogeneous compounds. None of these entered into the clinic, mainly because of inadequate biological effects. However, it appears that the ultimate goal of a clinically useful CCK₂R antagonist is now just around the corner, with the most promising compounds, netazepide and nastorazepide, now in Phase II clinical trials. Here, we illustrate the structure-activity relationships (SARs) of stablished CCK₂R antagonists of various structural classes, and the most recent proof-of-concept studies where new applicabilities of CCK₂R antagonists as visualizing agents are presented.

Neuroendocrine tumors of the gallbladder

A gallbladder neuroendocrine neoplasm (GB-NEN) is a unique heterogeneous neoplasm, originating from neuroendocrine cells and able to secrete peptides as its neurotransmitter. Among all the neuroendocrine tumors (NETs), the GB-NEN prevalence is 0.5%, which accounts for ~2.1% of all gallbladder tumors. The current study aimed to present an up-to-date review of the clinical features, diagnosis and treatment of NETs of the gallbladder. A systematic literature search was performed in order to identify all relevant studies published. Thus far, the etiology and pathogenesis of GB-NEN remains unclear. Moreover, an ambiguous clinical manifestation exists as observed during laboratory examinations. As GB-NEN is a rare gallbladder lesion and is seldom seen in clinical practice, there is a limited availability of review reports, and it is therefore often considered only as a case study. It is difficult to distinguish GB-NEN from other gallbladder diseases using imaging diagnostic techniques. Although chemotherapy treatment provides prolonged progression-free survival, surgery is considered the best option. Thus, to overcome the inherent risks or shortfalls of traditional surgery; early detection, diagnosis and treatment of GB-NEN are required to improve patient longevity.

Autoimmune metaplastic atrophic gastritis and association with neuroendocrine tumors of the stomach

Autoimmune metaplastic atrophic gastritis (AMAG) previously called type A chronic gastritis is an immune-mediated chronic inflammatory disease characterized by the immune-mediated destruction of gastric parietal cells in the fundus and body of the stomach. AMAG is an uncommon disease that often presents with hematological manifestations and may lead to the development of gastric carcinoids. AMAG can be reliably diagnosed by antibody assays, functional serology, and histology. The understanding of the disease process is essential for the detection and management of hematological complications and gastric lesions. The prevalence of AMAG is on the rise and subsequently gastric carcinoids. However, this association is not well recognized in clinical practice, and management and diagnosis of AMAG and gastric carcinoids remain suboptimal. In the current review, we will discuss the pathophysiology, diagnosis and management of AMAG. A special focus is given to the association between AMAG and gastric carcinoids. We will also review the management options of type 1 gastric carcinoids.

Chromogranin A in the Laboratory Diagnosis of Pheochromocytoma and Paraganglioma

This work discusses the clinical performance of chromogranin A (CGA), a commonly measured marker in neuroendocrine neoplasms, for the diagnosis of pheochromocytoma/paraganglioma (PPGL). Plasma CGA (cut-off value 150 µg/L) was determined by an immunoradiometric assay. Free metanephrine (cut-off value 100 ng/L) and normetanephrine (cut-off value 170 ng/L) were determined by radioimmunoassay. Blood samples were collected from PPGL patients preoperatively, one week, six months, one year and two years after adrenal gland surgery. The control patients not diagnosed with PPGL suffered from adrenal problems or from MEN2 and thyroid carcinoma. The clinical sensitivity in the PPGL group of patients (n = 71) based on CGA is 90% and is below the clinical sensitivity determined by metanephrines (97%). The clinical specificity based on all plasma CGA values after surgery (n = 98) is 99% and is the same for metanephrines assays. The clinical specificity of CGA in the control group (n = 85) was 92% or 99% using metanephrines tests. We can conclude that plasma CGA can serve as an appropriate complement to metanephrines assays in laboratory diagnosis of PPGL patients. CGA is elevated in PPGLs, as well as in other neuroendocrine or non-neuroendocrine neoplasia and under clinical conditions increasing adrenergic activity.

Neuroendocrine differentiation in castration resistant prostate cancer. Nuclear medicine radiopharmaceuticals and imaging techniques: A narrative review

BACKGROUND

Androgen Deprivation Therapy (ADT) is the primary treatment for patients suffering from relapsing or advanced prostate cancer (PC). Hormone therapy generally guarantees adequate clinical control of the disease for some years, even in those patients affected by widespread skeletal and soft tissue metastases. Despite ADT, however, most patients treated with hormones eventually progress to castration-resistant prostate cancer (CRPC), for which there are no effective treatments. This clinical reality is an open challenge to the oncologist because of those neoplasms which elaborate neuroendocrine differentiation (NED).

METHODS

An online search of current and past literature on NED in CRPC was performed. Relevant articles dealing with the biological and pathological basis of NED, with nuclear medicine imaging in CRPC and somatostatin treatment in NED were analyzed.

EVIDENCE FROM THE LITERATURE

NED may arise in prostate cancer patients in the late stages of ADT. The onset of NED offers prognostic insight because it reflects a dramatic increase in the aggressive nature of the neoplasm. Several genetic, molecular, cytological and immunohistochemical markers are associated with this transformation. Among these, overexpression of somatostatin receptors, seen through Nuclear Medicine testing, is one of the most studied.

CONCLUSIONS

Preliminary studies show that the overexpression of somatostatin receptors related to NED in CRPC may easily be studied in vivo with PET/CT. This finding offers a potentially useful objective for targeted therapy in CRPC. If the overexpression of SSTRs is shown to afflict a significant segment of patients with CRPC, this will open further study of possible therapeutic options based on this marker.

Interpretation of Unexpectedly High Levels of Endocrine Tumor Markers

OBJECTIVE

Endocrine tumor markers (ETMs) are important and indispensable tools in the diagnosis and follow-up of endocrine tumors. Unexpectedly high level of ETM (UHLETM) is often encountered in clinical practice. The objectives of this article are to discuss the approach to UHLETMs and describe the most common UHLETMs.

METHODS

Literature review and personal experience with UHLETMs.

RESULTS

A UHLETM is defined as an ETM level much higher than what an endocrinologist would expect based on the patient's clinical information, other biochemical test results, and imaging findings. Most UHLETMs are false positive, in that they do not indicate the existence or growth of an endocrine tumor. The key issue, however, is how to convincingly prove that a UHLETM is false positive. The most important question to help resolve UHLETMs is whether the UHLETMs are due to false or true results. Some UHLETMs are due to interpretation errors, laboratory errors, or spurious test results, while the true levels of the ETMs are normal or unchanged from previous results. Other UHLETMs are due to nontumor conditions or medications, and the true levels of the ETMs are indeed very high. When it is not straightforward to assess whether certain UHLETMs are due to false or true results, they may be due to novel conditions.

CONCLUSION

UHLETMs provide endocrinologists great opportunities to learn the basic biology and measurement of ETMs. Unresolved UHLETMs are exciting clinical research opportunities which may lead to discovery of new diseases and new mechanisms of measurement interference.

ABBREVIATIONS

5-HIAAA = 5-hydroxyindoleacetic acid; 5-HTP = 5-hydroxytryptophan; CGA = chromogranin A; ETM = endocrine tumor marker; MTC = medullary thyroid carcinoma; UHLETM = unexpectedly high level of endocrine tumor marker.

Chromogranin A: From Laboratory to Clinical Aspects of Patients with Neuroendocrine Tumors

Background. Neuroendocrine tumors (NETs) are characterized by having behavior and prognosis that depend upon tumor histology, primary site, staging, and proliferative index. The symptoms associated with carcinoid syndrome and vasoactive intestinal peptide tumors are treated with octreotide acetate. The PROMID trial assesses the effect of octreotide LAR on the tumor growth in patients with well-differentiated metastatic midgut NETs. The CLARINET trial evaluates the effects of lanreotide in patients with nonfunctional, well-, or moderately differentiated metastatic enteropancreatic NETs. Everolimus has been approved for the treatment of advanced pancreatic NETs (pNETs) based on positive PFS effects, obtained in the treated group. Sunitinib is approved for the treatment of patients with progressive gastrointestinal stromal tumor or intolerance to imatinib, because a randomized study demonstrated that it improves PFS and overall survival in patients with advanced well-differentiated pNETs. In a phase II trial, pasireotide shows efficacy and tolerability in the treatment of patients with advanced NETs, whose symptoms of carcinoid syndrome were resistant to octreotide LAR. An open-label, phase II trial assesses the clinical activity of long-acting repeatable pasireotide in treatment-naive patients with metastatic grade 1 or 2 NETs. Even if the growth of the neoplasm was significantly inhibited, it is still unclear whether its antiproliferative action is greater than that of octreotide and lanreotide. Because new therapeutic options are needed to counter the natural behavior of neuroendocrine tumors, it would also be useful to have a biochemical marker that can be addressed better in the management of these patients. Chromogranin A is currently the most useful biomarker to establish diagnosis and has some utility in predicting disease recurrence, outcome, and efficacy of therapy.

A score derived from routine biochemical parameters increases the diagnostic accuracy of chromogranin A in detecting patients with neuroendocrine neoplasms

BACKGROUND

Chromogranin A (CgA) is a valuable biomarker for detection and follow-up of patients with neuroendocrine neoplasms (NENs). However, various comorbidities may influence serum CgA, which decreases its diagnostic accuracy. We aimed to investigate which laboratory parameters are independently associated with increased CgA in real-life setting and to develop a scoring system, which could improve the diagnostic accuracy of CgA in detecting patients with NENs.

METHODS

This retrospective study included 55 treatment naïve patients with NENs and160 patients with various comorbidities but without NEN (nonNENs). Scoring system (CgA-score) was developed based on z-scores obtained from receiver operating curve analysis for each parameter that was associated with elevated serum CgA in nonNENs.

RESULTS

CgA correlated positively with serum BUN, creatinine, α2-globulin, red-cell distribution width, erythrocyte sedimentation rate, plasma glucose and correlated inversely with hemoglobin, thrombocytes and serum albumin. Serum CgA was also associated with the presence of chronic renal failure, arterial hypertension and diabetes and the use of PPI. In the entire study population, CgA showed an area under the curve of 0.656. Aforementioned parameters were used to develop a CgA-score. In a cohort of patients with CgA-score <12.0 (N = 87), serum CgA >156.5 ng/ml had 77.8% sensitivity and 91.5% specificity for detecting NENs (AUC 0.841, 95% CI 0.713-0.969, P < 0.001). Serum CgA had no diagnostic value in detecting NENs in patients with CgA-score >12.0 (AUC 0.554, 95% CI 0.405-0.702, P = 0.430).

CONCLUSIONS

CgA-score encompasses a wide range of comorbidities and represents a promising tool that could improve diagnostic performance of CgA in everyday clinical practice.

Regulation of tumor growth by circulating full-length chromogranin A

Chromogranin A (CgA), a neuroendocrine secretory protein, and its fragments are present in variable amounts in the blood of normal subjects and cancer patients. We investigated whether circulating CgA has a regulatory function in tumor biology and progression. Systemic administration of full-length CgA, but not of fragments lacking the C-terminal region, could reduce tumor growth in murine models of fibrosarcoma, mammary adenocarcinoma, Lewis lung carcinoma, and primary and metastatic melanoma, with U-shaped dose-response curves. Tumor growth inhibition was associated with reduction of microvessel density and blood flow in neoplastic tissues. Neutralization of endogenous CgA with antibodies against its C-terminal region (residues 410-439) promoted tumor growth. Structure-function studies showed that the C-terminal region of CgA contains a bioactive site and that cleavage of this region causes a marked loss of anti-angiogenic and anti-tumor potency. Mechanistic studies showed that full-length CgA could induce, with a U-shaped dose-response curve, the production of protease nexin-1 in endothelial cells, a serine protease inhibitor endowed of anti-angiogenic activity. Gene silencing or neutralization of protease nexin-1 with specific antibodies abolished both anti-angiogenic and anti-tumor effects of CgA. These results suggest that circulating full-length CgA is an important inhibitor of angiogenesis and tumor growth, and that cleavage of its C-terminal region markedly reduces its activity. Pathophysiological changes in CgA blood levels and/or its fragmentation might regulate disease progression in cancer patients.

Pitfalls in the Diagnosis of Neuroendocrine Tumors: Atypical Clinical and Radiological Findings as Cause of Medical Mistakes

Aims and background

Carcinoids are infrequent neoplasms arising from neuroendocrine cells. Due to blurred symptoms and the presence of equivocal diagnostic findings, these tumors are sometimes misdiagnosed. Therefore, increased rates of false neuroendocrine tumors represent an emerging problem in clinical practice. Our aim is to alert clinicians on this matter by supplying them with useful warnings.

Methods

In the specialized neuroendocrine tumor study Center Centro di Riferimento per lo Studio e la Cura dei Carcinoidi e dei Tumori Neuroendocrini (Ce.Ri.Ca), some patients highly suspected to have a neuroendocrine tumor have been recognized as having false neuroendocrine tumors. The related clinical and instrumental findings leading to a previous wrong neuroendocrine tumor diagnosis are reported.

Results

From July 2006 to December 2008, 88 consecutive cases of neuroendocrine tumors (Nets) were referred at Ce.Ri.Ca. In the former group, 8 cases of false Nets were discovered while in the remaining 80 cases a correct Net diagnosis was carried out. Watchful differential diagnoses and skill appraisal of laboratory investigations resulted in: chronic atrophic gastritis with enterochromaffin-like cell hyperplasia (4 cases), estrogen-deprivation syndrome (1), hypochondriac disorder (1), metabolic syndrome (1), and sarcoidosis (1).

Conclusions

Neuroendocrine tumors are still relatively known clinical entities. To discriminate false neuroendocrine tumors from neuroendocrine tumors requires a good expertise and a large daily practice with the disease. Good knowledge and skillfulness in identifying biochemical alterations and false radiological positive results could avoid both patient inconvenience and very expensive workup. The importance of a multidisciplinary approach in specialized centers is emphasized.

Comparison between Two Methods in the Determination of Circulating Chromogranin A in Neuroendocrine Tumors (NETs): Results of a Prospective Multicenter Observational Study

Several methods for analyzing CgA using either monoclonal or polyclonal antibodies have been developed, which differ in their diagnostic performance. The present paper describes the results of a prospective multicenter study aimed at comparing the clinical value of the two most widely used commercially available CgA assay kits in patients affected by neuroendocrine tumors (NETs). Two hundred sixty-one patients from 40 different centers and 99 healthy subjects were evaluated. CgA levels were measured with two different methods, a two-step immunoradiometric assay (IRMA) and an enzyme-linked immunosorbent assay (ELISA). CgA was measured centrally by two reference laboratories, one of which used IRMA and the other ELISA, and it was measured by the participating institutions with the method routinely used by each of them. The major findings of the present study were: (i) the two assays for the determination of CgA present good diagnostic performance; (ii) both assays are robust and guarantee comparable results when applied in different settings (central vs local laboratory); (iii) the negative/positive cutoff points (87 ng/mL for IRMA and 21.3 U/L for ELISA) were established according to standardized criteria; (iv) the results obtained with the two assays in basal clinical samples of patients affected by NETs show an apparently satisfactory correlation (rs=0.843, p<0.0001). However, a possibly clinically meaningful 36% discordance rate was found. These findings support the hypothesis that the two CgA kits might provide partially different information.

Chromogranin A as circulating marker for diagnosis and management of neuroendocrine neoplasms: more flaws than fame

Owing to the heterogeneity of neuroendocrine neoplasms (NENs), the availability of reliable circulating markers is critical for improving diagnostics, prognostic stratification, follow-up and definition of treatment strategy. This review is focused on chromogranin A (CgA), a hydrophilic glycoprotein present in large dense core vesicles of neuroendocrine cells. Despite being long identified as the most useful NEN-related circulating marker, clinical application of CgA is controversial. CgA assays still lack standardization, thus hampering not only clinical management but also the comparison between different analyses. In the diagnostic setting, clinical utility of CgA is limited as hampered by (a) the variety of oncological and non-oncological conditions affecting marker levels, which impairs specificity; (b) the fact that 30-50% of NENs show normal CgA, which impairs sensitivity. Regarding the prognostic phase, there is prospective evidence which demonstrates that advanced NENs secreting CgA have poorer outcome, as compared with those showing non-elevated marker levels. Although the identification of cut-offs allowing a proper risk stratification of CgA-secreting patients has not been performed, this represents the most important clinical application of the marker. By contrast, based on prospective studies, the trend of elevated circulating CgA does not represent a valid indicator of morphological evolution and has therefore no utility for the follow-up phase. Ultimately, current knowledge about the role of the marker for the definition of treatment strategy is poor and is limited by the small number of available studies, their prevalent retrospective nature and the absence of control groups of untreated subjects.

Risk factors of type 1 gastric neuroendocrine neoplasia in patients with chronic atrophic gastritis. A retrospective, multicentre study

The aim of this retrospective study was to evaluate the presence of risk factors for a type 1 gastric neuroendocrine neoplasia in a large cohort of patients with chronic atrophic gastritis. The study design consisted of an Italian multicentre, retrospective analysis. The study included all consecutive patients with chronic atrophic gastritis with or without type 1 gastric neuroendocrine neoplasias followed at the participating centres. Two hundred and twenty-nine patients with chronic atrophic gastritis were enroled at the participating centres. A total of 207 patients (154 female, 53 males, median age: 56.0 years) were included in the final analysis. One hundred and twenty-six patients had chronic atrophic gastritis without a gastric neuroendocrine neoplasia and 81 had a chronic atrophic gastritis with type 1 gastric neuroendocrine neoplasia. The median Chromogranin A level, evaluated in 141 patients, was 52.0 U/L. At upper gastrointestinal endoscopy, atrophy of the gastric mucosa was mild/moderate in 137 patients and severe in 68. Intestinal metaplasia of the corpus was present in 168 patients. At histological examination, 81 patients had a gastric neuroendocrine neoplasia (42 patients had a NET G1 and 33 a NET G2). The median Ki67 index was 2.0 %. At univariate and multivariate analysis, the risk factors for a gastric neuroendocrine neoplasia were: male gender, chromogranin A greater than 61 U/L, presence of intestinal metaplasia and age equal to or greater than 59 years. Chromogranin A greater than 61 U/L, the presence of intestinal metaplasia and male gender were independent risk factors for a type 1 gastric neuroendocrine neoplasia in patients with chronic atrophic gastritis.

Autoimmune atrophic gastritis: current perspectives

At present there is no universally accepted classification for gastritis. The first successful classification (The Sydney System) that is still commonly used by medical professionals was first introduced by Misiewicz et al in Sydney in 1990. In fact, it was the first detailed classification after the discovery of Helicobacter pylori by Warren and Marshall in 1982. In 1994, the Updated Sydney System was proposed during the International Workshop on the Histopathology of Gastritis followed by the publication in The American Journal of Surgical Pathology by Dixon et al. Using the new classification, distinction between atrophic and nonatrophic gastritis was revised, and the visual scale grading was incorporated. According to the Updated Sydney System Classification, atrophic gastritis is categorized into multifocal (H. pylori, environmental factors, specific diet) and corpus-predominant (autoimmune). Since metaplasia is a key histological characteristic in patients with atrophic gastritis, it has been recommended to use the word “metaplastic” in both variants of atrophic gastritis: autoimmune metaplastic atrophic gastritis (AMAG) and environmental metaplastic atrophic gastritis. Although there are many overlaps in the course of the disease and distinction between those two entities may be challenging, the aim of this review article was to describe the etiology, epidemiology, pathogenesis, diagnosis, clinical manifestations and treatment in patients with AMAG. However, it is important to mention that H. pylori is the most common etiologic factor for the development of gastritis in the world.

Netazepide, a gastrin/cholecystokinin-2 receptor antagonist, can eradicate gastric neuroendocrine tumours in patients with autoimmune chronic atrophic gastritis

AIMS

Netazepide, a gastrin/cholecystokinin 2 receptor antagonist, once daily for 12 weeks reduced the number of tumours and size of the largest one in 16 patients with autoimmune chronic atrophic gastritis (CAG), achlorhydria, hypergastrinaemia and multiple gastric neuroendocrine tumours (type 1 gastric NETs), and normalized circulating chromogranin A (CgA) produced by enterochromaffin-like cells, the source of the tumours. The aim was to assess whether longer-term netazepide treatment can eradicate type 1 gastric NETs.

METHODS

After a mean 14 months off netazepide, 13 of the 16 patients took it for another 52 weeks. Assessments were: gastroscopy; gene-transcript expression in corpus biopsies using quantitative polymerase chain reaction; blood CgA and gastrin concentrations; and safety assessments.

RESULTS

While off-treatment, the number of tumours, the size of the largest one, and CgA all increased again. Netazepide for 52 weeks: cleared all tumours in 5 patients; cleared all but one tumour in one patient; reduced the number of tumours and size of the largest one in the other patients; normalized CgA in all patients; and reduced mRNA abundances of CgA and histidine decarboxylase in biopsies. Gastrin did not increase further, confirming that the patients had achlorhydria. Netazepide was safe and well tolerated.

CONCLUSIONS

A gastrin/cholecystokinin 2 receptor antagonist is a potential medical and targeted treatment for type 1 gastric NETs, and an alternative to regular gastroscopy or surgery. Treatment should be continuous because the tumours will regrow if it is stopped. Progress can be monitored by CgA in blood or biomarkers in mucosal biopsies.

The gastrin receptor antagonist netazepide (YF476) in patients with type 1 gastric enterochromaffin-like cell neuroendocrine tumours: review of long-term treatment

OBJECTIVE

Netazepide (YF476) is a recently developed, orally active gastrin receptor antagonist that, in short trials in patients with type 1 gastric enterochromaffin-like cell neuroendocrine tumours, has been shown to induce a significant reduction in the number and size of tumours as well as serum chromogranin A (CgA). The aim of this review is to evaluate the long-term effect and safety of netazepide.

PATIENTS AND METHODS

Five patients previously treated with netazepide in an open-label trial were offered continuous treatment with netazepide 25 mg once daily. Upper endoscopy was performed every 6 months. The tumours were counted and measured, and tissue samples were obtained from the flat corpus mucosa. Enterochromaffin-like cell hyperplasia was classified according to Solcia and colleagues and volume density of CgA immunoreactive (IR) cells was calculated. Fasting serum CgA and fasting serum gastrin were measured every 3 months.

RESULTS

All tumours regressed completely in three of five patients; time until total disappearance was 3, 9 and 12 months. In the other two patients, the number of tumours was reduced from 13 to 5 and from 14 to 3. Serum CgA showed a rapid and sustained decrease (P<0.001). The mean reduction in serum CgA was 4.1±0.5 nmol/l. Similarly, volume density of CgA IR cells in the flat corpus mucosa decreased (P<0.001), with the mean change being 2.0±0.4%. Serum gastrin and volume density of gastrin IR cells in the antral part of the stomach remained unchanged (P=0.2 and 0.7, respectively).

CONCLUSION

Long-term administration of netazepide is effective and safe.

Gastric neuroendocrine neoplasms and proton pump inhibitors: fact or coincidence?

OBJECTIVE

Reporting on three cases of gastric neuroendocrine tumors (g-NETs) in patients taking long-term proton pump inhibitors (PPIs). These tumors are not classifiable considering current criteria. g-NETs are currently grouped as: types 1 and 2, related to hypergastrinemia due to chronic atrophic gastritis and Zollinger-Ellison syndrome respectively, and type 3, normogastrinemic and more aggressive. Although the g-NETs onset in patients taking PPIs is biologically plausible, only a few cases have been reported so far.

MATERIALS AND METHODS

From January 2005 to July 2014, 31 g-NETs were referred to our Unit: 24 (77%), one (3%) and three (10%) resulted types 1, 2 and 3, respectively. Three cases (10%) did not meet the current classification criteria.

RESULTS

The three patients were administered long-term PPIs for gastro-esophageal reflux disease. Patient 1: a 78-year-old man, with a 4-mm well-differentiated g-NET (Ki-67<1%) and marked hypergastrinemia. Patient 2: a 58-year-old man affected by a 6-mm well-differentiated (Ki-67 = 4%) g-NET, with normal gastrin levels. Patients 3: a 67-year-old woman with an 18-mm well-differentiated g-NET (Ki-67 <2%), with mild hypergastrinemia. In the three patients, histology and pertinent blood tests excluded chronic atrophic gastritis, Helicobacter pylori infection or Zollinger-Ellison syndrome. The first two patients underwent endoscopic polypectomy; in the third case total gastrectomy was performed. Further clinical, endoscopic and imaging follow-up did not show any g-NET recurrence.

CONCLUSIONS

The present data point to the existence and epidemiological relevance of g-NETs associated with PPIs intake. These neoplasms are not included in the current classification, thus their treatment and follow-up have not been established.

Intermittent treatment of recurrent type-1 gastric carcinoids with somatostatin analogues in patients with chronic autoimmune atrophic gastritis

BACKGROUND

Optimal management and treatment of type-1 gastric carcinoids is under debate.

AIMS

This prospective study evaluates the outcome of patients with recurrent type-1 gastric carcinoids treated with somatostatin analogues.

METHODS

From 2000 to 2013, among a population of 107 chronic atrophic gastritis patients, 25 (20% males, median age 62 years) developed type-1 gastric carcinoids and underwent regular clinical and endoscopic follow-up (median 77 months, range 6-165) after the initial treatment. Those patients showing recurrent disease were treated with somatostatin analogues until carcinoid disappearance.

RESULTS

12/25 patients (33% males, median age 65 years) showed recurrent gastric carcinoids and were treated with somatostatin analogues for a median duration of 12 months. Median gastrin and chromogranin A levels, which were 802 pg/mL and 33 U/L, respectively, decreased to 299 pg/mL (p=0.002) and 15.6 U/L (p=0.001) at the end of the treatment. Gastric carcinoids disappeared after a median length of treatment of 12 months. After a median time of 19.5 months from somatostatin analogues discontinuation, 4/12 patients (25% males, median age 56 years) showed a further recurrence. A new cycle of treatment was performed successfully.

CONCLUSIONS

This study confirms that type-1 gastric carcinoids are a recurring disease and somatostatin analogues, administered on 12-month cycles, represent an effective treatment.

Current concepts in the diagnosis and management of type 1 gastric neuroendocrine neoplasms

The vast majority of gastrin-related gastrointestinal neuroendocrine neoplasms (GI-NENs) develop in the context of chronic atrophic gastritis (type 1), a condition closely related to autoimmune thyroid diseases. These neoplasms are defined as gastric NENs type 1 (GNEN1) and have recently been shown to constitute the commonest GI-NENs in a prospective study. GNEN1s are usually multiple and follow a relative indolent course, raising questions regarding the extent that such patients should be investigated and the appropriate therapeutic interventions needed. Recently, a number of consensus statements and guidelines have been published from various societies dealing with the diagnosis and management of GI-NENs. Endocrinologists are among the many different medical specialties involved in GNEN1s diagnosis and management. However, despite recent advances, few randomized trials are available, and thus existing evidence remains relatively weak compared to other malignancies. The purpose of this review is to provide recent evidence along with currently employed modalities addressing the diagnosis, management, long-term follow-up and potential comorbidities of GNEN1s.

Are patients with autoimmune thyroid disease and autoimmune gastritis at risk of gastric neuroendocrine neoplasms type 1?

OBJECTIVE

The aim of this study was to investigate the prevalence of autoimmune gastritis, enterochromaffin-like cell (ECL-cell) hyperplasia and gastric neuroendocrine neoplasms type 1 (GNEN1) in patients with autoimmune thyroid disease.

DESIGN

Prospective observational study in a single institutional study.

PATIENTS AND MEASUREMENTS

One hundred and twenty patients with autoimmune thyroid disease were consecutively recruited from the Endocrine Unit. Upper gastrointestinal tract endoscopy (UGE) and biochemical parameters for autoimmune thyroid disease and autoimmune gastritis were assessed at recruitment and annually thereafter in patients with a mean follow-up of 37·5 ± 14·4 months. Autoimmune gastritis was defined by the presence of antiparietal cell antibodies (APCA) and histological confirmation after UGE. Serum gastrin and chromogranin Α were also measured.

RESULTS

One hundred and eleven patients had Hashimoto's thyroiditis and nine Graves' disease. Autoimmune gastritis was identified in 40 (38 with Hashimoto's thyroiditis and two with Graves' disease) patients all of whom had increased levels of gastrin and chromogranin Α; Helicobacter pylori infection was histologically identified in 15 of 40 (37·5%) patients. Six patients had isolated nodular ECL-cell hyperplasia and one mixed nodular and linear ECL-cell hyperplasia [7 of 40 (17·5%)]. Only increased gastrin (P = 0·03) levels predicted the presence ECL-cell hyperplasia. A GNEN1 developed in one patient with nodular ECL-cell hyperplasia after 39 months of follow-up.

CONCLUSIONS

Concomitant autoimmune gastritis was found in 33·3% of patients with autoimmune thyroid disease, 17·5% of whom had ECL-cell hyperplasia that evolved to GNEN1 in one (2·5%). Larger studies with longer follow-up are needed to define the incidence of GNEN1 in patients with autoimmune thyroid disease and ECL-cell hyperplasia and potential implications.

Biological function and clinical relevance of chromogranin A and derived peptides

Chromogranin A (CgA (CHGA)) is the major soluble protein co-stored and co-released with catecholamines and can function as a pro-hormone by giving rise to several bioactive peptides. This review summarizes the physiological functions, the pathogenic implications, and the recent use of these molecules as biomarkers in several pathological conditions. A thorough literature review of the electronic healthcare databases MEDLINE, from January 1985 to September 2013, was conducted to identify articles and studies concerned with CgA and its processing. The search strategies utilized keywords such as chromogranin A, vasostatins 1 and 2, chromofungin, chromacin, pancreastatin, catestatin, WE14, chromostatin, GE25, parastatin, and serpinin and was supplemented by the screening of references from included papers and review articles. A total of 209 English-language, peer-reviewed original articles or reviews were examined. The analysis of the retrospective literature suggested that CgA and its several bioactive fragments exert a broad spectrum of regulatory activities by influencing the endocrine, the cardiovascular, and the immune systems and by affecting the glucose or calcium homeostasis. As some peptides exert similar effects, but others elicit opposite responses, the regulation of the CgA processing is critical to maintain homeostasis, whereas an unbalanced production of peptides that exert opposing effects can have a pathogenic role in several diseases. These clinical implications entail that CgA and its derived peptides are now used as diagnostic and prognostic markers or to monitor the response to pharmacological intervention not only in endocrine tumors, but also in cardiovascular, inflammatory, and neuropsychiatric diseases.

Predictive value of gastrin levels for the diagnosis of gastric enterochromaffin-like cell hyperplasia in patients with Hashimoto's thyroiditis

AIM

Gastrin and chromogranin A (CgA) levels have been tested for the diagnosis of enterochromaffin-like cell hyperplasia (ECLH) in patients with type 1 diabetes and autoimmune atrophic gastritis but not for patients with Hashimoto's thyroiditis (HT). The aim of the study was to develop receiver operating characteristic (ROC) curves for gastrin and CgA levels and other clinical and biochemical parameters, as means for pretest probability of gastric ECLH in patients with HT.

METHODS

A total of 115 patients with HT were prospectively studied for a median period of 4 (2-7) years. Gastrin, CgA, vitamin B12, anti-parietal cell antibodies, free thyroxine, thyrotropin, and neuron-specific enolase levels were measured. Their predictive values were calculated according to the histological findings for ECLH diagnosis from esophagogastroduodenoscopy-obtained biopsies.

RESULTS

Thirteen patients (11.3%) had ECLH. The areas under the curve for gastrin and CgA level were 0.898 (p < 0.001) and 0.853 (p < 0.001), respectively. The product sensitivity × specificity was 0.803 and 0.653 for gastrin and CgA levels >89.5 and >89.1 ng/ml, respectively. Two and 4 patients with ECLH had normal gastrin and CgA levels, respectively. The most specific combined parameters predicting ECLH were gastrin >89.5 ng/ml with concomitant low B12 levels (96.1% specificity).

CONCLUSION

Gastrin levels have high diagnostic accuracy for ECLH identification in patients with HT, and are highly specific when combined with low B12 levels. However, they should be interpreted with caution, as some patients may harbor gastric ECLH even if gastrin levels are not increased, necessitating further follow-up.

[Biomarkers in endocrinology]

TSH assay is the best parameter of the thyroid function. For adults, the normal interval of TSH concentrations range from 0.4 to 4 mUI/L. At the first trimester of pregnancy, TSH levels must be <2.5 mUI/L. Normal TSH levels increase with aging and obesity. The biological diagnosis relies on the identification of excessive secretion of the metanephrines which are more sensitive and specific than those of catecholamines. The concentrations of the free plasmatic metanephrines reflect the ongoing production of tumor. Plasma methoxytyramine is a novel biomarker of metastatic pheochromocytomas and paragangliomas. Serum IGF1 is a reliable measure of integrated GH concentrations in patients with acromegaly. Accurate assessment of IGF1 concentrations requires age and sex-matched control values. IGF1 is a sensitive tool for the diagnosis of acromegaly and efficacy of therapies. Serum AMH assay is more sensitive, more specific and more reproducible that counting of ovarian follicles by ultrasound. AMH level above 5 ng/mL (35 pmol/L) could be chosen as one of the diagnostic criteria for the polycystic ovary syndrome. In early or "incipiens" ovarian failure, the decrease in serum AMH is far ahead of the increase in FSH. Thyroglobulin (TG) and calcitonin (CT) are the sensitive and specific markers of respectively well-differentiated thyroid cancers of follicular origin and of the medullary thyroid cancers. The same tumour marker assay should be used to monitor a given patient. Chromogranin A (CgA) is a highly efficient biomarker for diagnosis and follow-up of various endocrine tumours. Despite the lack of international standardisation, some CgA assays are reliable.

Netazepide, a gastrin receptor antagonist, normalises tumour biomarkers and causes regression of type 1 gastric neuroendocrine tumours in a nonrandomised trial of patients with chronic atrophic gastritis

INTRODUCTION

Autoimmune chronic atrophic gastritis (CAG) causes hypochlorhydria and hypergastrinaemia, which can lead to enterochromaffin-like (ECL) cell hyperplasia and gastric neuroendocrine tumours (type 1 gastric NETs). Most behave indolently, but some larger tumours metastasise. Antrectomy, which removes the source of the hypergastrinaemia, usually causes tumour regression. Non-clinical and healthy-subject studies have shown that netazepide (YF476) is a potent, highly selective and orally-active gastrin/CCK-2 receptor antagonist. Also, it is effective in animal models of ECL-cell tumours induced by hypergastrinaemia.

AIM

To assess the effect of netazepide on tumour biomarkers, number and size in patients with type I gastric NETs.

METHODS

We studied 8 patients with multiple tumours and raised circulating gastrin and chromogranin A (CgA) concentrations in an open trial of oral netazepide for 12 weeks, with follow-up 12 weeks later. At 0, 6, 12 and 24 weeks, we carried out gastroscopy, counted and measured tumours, and took biopsies to assess abundances of several ECL-cell constituents. At 0, 3, 6, 9, 12 and 24 weeks, we measured circulating gastrin and CgA and assessed safety and tolerability.

RESULTS

Netazepide was safe and well tolerated. Abundances of CgA (p<0.05), histidine decarboxylase (p<0.05) and matrix metalloproteinase-7(p<0.10) were reduced at 6 and 12 weeks, but were raised again at follow-up. Likewise, plasma CgA was reduced at 3 weeks (p<0.01), remained so until 12 weeks, but was raised again at follow-up. Tumours were fewer and the size of the largest one was smaller (p<0.05) at 12 weeks, and remained so at follow-up. Serum gastrin was unaffected.

CONCLUSION

The reduction in abundances, plasma CgA, and tumour number and size by netazepide show that type 1 NETs are gastrin-dependent tumours. Failure of netazepide to increase serum gastrin further is consistent with achlorhydria. Netazepide is a potential new treatment for type 1 NETs. Longer, controlled trials are justified.

TRIAL REGISTRATION

European Union EudraCT database 2007-002916-24 https://www.clinicaltrialsregister.eu/ctr-search/search?query=2007-002916-24ClinicalTrials.gov NCT01339169 http://clinicaltrials.gov/ct2/show/NCT01339169?term=yf476&rank=5.

Serum pancreastatin: the next predictive neuroendocrine tumor marker

BACKGROUND AND OBJECTIVES

Pancreastatin is a derived peptide of chromogranin A (CgA). Pancreastatin has the potential to be a diagnostic and predictive tumor marker in detecting NETs.

METHODS

Radioimmunoassay tests of pancreastatin and CgA were performed on 103 patient specimens collected at Mount Sinai Medical Center between 1/2010 and 7/2012. Patient demographics, diagnostic tests, surgical procedures, pathologic findings, adjuvant treatments, and survival were retrospectively reviewed. Statistical analysis utilized SPSS v20 software.

RESULTS

Mean pancreastatin levels were significantly higher in the 92 NETs patients than in the 11 non-NETs patients (227.261 vs. 59.727, P < 0.05). Twenty-seven of the 92 patients with elevated pancreastatin levels (mean = 240.67), had normal CgA levels (mean = 4.65). Pancreastatin had sensitivity and specificity of 64% (59/92), and 100% (11/11). CgA had lower sensitivity and specificity of 43% (40/92), and 64% (7/11). In all 27 instances the pancreastatin concentration was found to be sole indicator of NET disease. When controlling for the level of CgA for the entire sample, a statistically significant difference was not found in the mean pancreastatin levels between both patient groups (P = 0.139, R = 0.484).

CONCLUSION

Pancreastatin has greater sensitivity and specificity in diagnosing NETs than CgA. Further investigation of pancreastatin's diagnostic and predictive value is warranted.

Sunitinib malate as first-line treatment for an advanced, poorly differentiated pancreatic neuroendocrine tumor

Pancreatic neuroendocrine tumors (PNETs) are rare, accounting for approximately 2% of primary malignant tumors of the pancreas. Compared with common pancreatic ductal adenocarcinomas, they grow more slowly, are less invasive and have a better prognosis. At present, surgery is the preferred method of treatment of PNETs, and offers the only chance of a cure. However, owing to the occult onset of PNETs, once diagnosed they are often inoperable when the diagnosis is established, and the optimal treatment of patients with inoperable liver metastases remains uncertain. In recent years, targeted drug therapies have emerged and have proved effective in prolonging progression-free survival in patients with advanced well-differentiated PNETs, but hardly any progress has been made in the treatment of poorly differentiated PNETs. In the patient described in this report, who had a poorly differentiated PNET with multiple hepatic metastases and had refused cytotoxic chemotherapy, oral sunitinib malate treatment for 22 months with regular follow-ups proved tolerable and effective in significantly reducing the size of the intrahepatic masses.

Chronic autoimmune atrophic gastritis associated with primary hyperparathyroidism: a transversal prospective study

DESIGN

The coexistence of chronic autoimmune atrophic gastritis (CAAG) and primary hyperparathyroidism (PHPT) has been described previously, even if its extent and underlying mechanisms remain poorly understood. We therefore prospectively evaluated this association in two series of patients, one with CAAG and the other with sporadic PHPT.

METHODS

From January 2005 to March 2012, 107 histologically confirmed CAAG patients and 149 PHPT patients were consecutively enrolled. Routine laboratory assays included serum calcium, parathyroid hormone (PTH), plasma gastrin and chromogranin A (CgA). In CAAG patients with high PTH levels, ionized calcium and 25(OH)-vitamin D were evaluated. All CAAG and hypergastrinemic PHPT patients received an upper gastrointestinal endoscopy. Exclusion criteria were familial PHPT, MEN1 syndrome, treatment with proton pump inhibitor drugs, Helicobacter pylori infection and renal failure.

RESULTS

Of the 107 CAAG patients, nine (8.4%) had PHPT and 13 (12.1%) had secondary hyperparathyroidism stemming from vitamin D deficiency. Among the 149 PHPT patients, 11 (7.4%) had CAAG. Gastrin and CgA levels were similar in the CAAG patients with vs those without hyperparathyroidism (either primary or secondary), and calcium and PTH levels were similar in the PHPT patients with vs those without CAAG.

CONCLUSIONS

This study confirms a non-casual association between PHPT and CAAG. The prevalence of PHPT in CAAG patients is threefold that of the general population (8.4 vs 1-3%), and the prevalence of CAAG in PHPT patients is fourfold that of the general population (7.4 vs 2%). The mechanisms underlying this association remain unknown, but a potential role for autoimmunity is suggested.

Pancreatic neuroendocrine tumors: biology, diagnosis,and treatment

Pancreatic neuroendocrine tumors (PNETs), a group of endocrine tumors arising in the pancreas, are among the most common neuroendocrine tumors. The genetic causes of familial and sporadic PNETs are somewhat understood, but their molecular pathogenesis remains unknown. Most PNETs are indolent but have malignant potential. The biological behavior of an individual PNET is unpredictable; higher tumor grade, lymph node and liver metastasis, and larger tumor size generally indicate a less favorable prognosis. Endocrine testing, imaging, and histological evidence are necessary to accurately diagnose PNETs. A 4-pronged aggressive treatment approach consisting of surgery, locoregional therapy, systemic therapy, and complication control has become popular in academic centers around the world. The optimal application of the multiple systemic therapeutic modalities is under development; efficacy, safety, availability, and cost should be considered when treating a specific patient. The clinical presentation, diagnosis, and treatment of specific types of PNETs and familial PNET syndromes, including the novel Mahvash disease, are summarized.

Treatment of gastric carcinoids type 1 with the gastrin receptor antagonist netazepide (YF476) results in regression of tumours and normalisation of serum chromogranin A

BACKGROUND

Patients with chronic atrophic gastritis have long-term gastric hypoacidity, and secondary hypergastrinaemia. Some also develop gastric ECL cells carcinoids (type 1 GC). Most type 1 GC remain indolent, but some metastasise. Patients undergo surveillance, and some are treated with somatostatin analogues, endoscopic resection or surgery. Netazepide (YF476) is a highly selective, potent and orally active gastrin receptor antagonist, which has anti-tumour activity in various rodent models of gastric neoplasia driven by hypergastrinaemia. Netazepide has been studied in healthy volunteers.

AIM

To assess the effect of netazepide on type 1 GC.

METHODS

Eight patients with multiple type 1 GC received oral netazepide once daily for 12 weeks, with follow-up at 12 weeks in an open-label, pilot trial. Upper endoscopy was performed at 0, 6, 12 and 24 weeks, and carcinoids were counted and measured. Fasting serum gastrin and chromogranin A (CgA) and safety and tolerability were assessed at 0, 3, 6, 9, 12 and 24 weeks.

RESULTS

Netazepide was well tolerated. All patients had a reduction in the number and size of their largest carcinoid. CgA was reduced to normal levels at 3 weeks and remained so until 12 weeks, but had returned to pre-treatment levels at 24 weeks. Gastrin remained unchanged throughout treatment.

CONCLUSIONS

The gastrin receptor antagonist netazepide is a promising new medical treatment for type 1 gastric carcinoids, which appear to be gastrin-dependent. Controlled studies and long-term treatment are justified to find out whether netazepide treatment can eradicate type 1 gastric carcinoids.

Gastric neuroendocrine tumours

BACKGROUND

Gastric neuroendocrine tumours (NETs) are increasingly recognised, and management decisions may be difficult due to an incomplete understanding of aetiology, natural history and optimum therapy. This article presents a current understanding based on recent advances in epidemiology, classification, molecular profiling, and treatment.

METHODS

Relevant medical literature was identified from searches of PubMed and references cited in appropriate articles identified. Selection of articles was based on peer review, journal and relevance.

RESULTS

Gastric NETs may be divided into three clinical prognostic groups: type I is associated with autoimmune atrophic gastritis and hypergastrinaemia, type II is associated with Zollinger-Ellison syndrome, and type III lesions are gastrin-independent, have the greatest metastatic potential and poorest prognosis. There has been an increased frequency of gastric NETs reported. Management approaches have evolved in parallel with advances in endoscopic staging and surgery, as well as improved understanding of the biology and natural history of NETs.

CONCLUSIONS

Gastric NETs present a spectrum of activity from indolent tumours to metastatic malignancy. Treatment decisions for patients must be individualised and are best managed by a multidisciplinary team approach. The current evidence base is limited to small series and efforts to treat patients within clinical networks of expertise are warranted.

Improved diagnostic accuracy for neuroendocrine neoplasms using two chromogranin A assays

CONTEXT

Chromogranin A (Cg A) is the best available diagnostic marker for neuroendocrine neoplasms (NENs). However, clinical interpretation of Cg A results may be limited by considerable heterogeneity between commonly available Cg A assays. Variation in diagnostic accuracy of these assays largely reflects differences in antibody specificities. We compared the diagnostic utility of four Cg A assays [Imperial Supra-regional Assay Service radioimmunoassay (SAS) and three commercial assays, Cisbio, DAKO and Eurodiagnostica].

METHOD

Plasma Cg A was measured using these four assays in 125 patients with NENs, 41 patients with cancers other than NENs and 108 healthy controls.

RESULT

There was no significant difference in diagnostic accuracy between any of the four assays alone and no single assay positively identified all patients with NEN. However, concordance between assays was variable. Cisbio and SAS assays were least concordant. We, therefore, hypothesized that using a combination of the least concordant Cg A assays will improve NEN diagnosis by detecting a larger number of Cg A epitopes and hence patients with NEN. Consistent with our hypothesis, multiple logistic regression analysis showed that the combination of Cisbio and SAS assays was more useful than any other combinations or any assay alone in predicting a NEN diagnosis.

CONCLUSION

Although individually, all four Cg A assays are similarly useful for the measurement of Cg A in the diagnosis of a NEN, in patients with a suspected NEN, negative results by one assay should prompt analysis by a second assay. The combination of Cisbio and SAS assays may have greatest diagnostic utility.

Is ⁶⁸Ga-DOTA-NOC PET/CT indicated in patients with clinical, biochemical or radiological suspicion of neuroendocrine tumour?

PURPOSE

In recent years, (68)Ga-DOTA-peptides positron emission tomography (PET)/CT has been increasingly used to study patients with neuroendocrine tumours (NET). However, performing specialized examinations in the appropriate contest is mandatory for both medical and economic reasons. The aim of the study is to evaluate the potential usefulness of (68)Ga-DOTA-NOC PET/CT in patients with suspected NET.

METHODS

Among the patients undergoing (68)Ga-DOTA-NOC PET/CT at our centre, we reviewed those studied for suspected NET based on the presence of either clinical signs/symptoms or imaging or raised biochemical markers or a combination of these conditions. PET/CT results were compared with clinical and imaging follow-up of at least 1 year or pathology.

RESULTS

Overall 131 suspected NET cases were included. The most common condition considered suspicious for NET was the increase of blood markers (66), followed by inconclusive findings at conventional imaging (CI, 41), clinical signs/symptoms (10), equivocal (18)F-fluorodeoxyglucose (FDG) PET (7) or somatostatin receptor scintigraphy (SRS, 4), or a combination of the above (3). PET/CT results were true-positive in 17 cases, true-negative in 112 and false-negative in 2 (overall sensitivity 89.5 %, specificity 100 %). Interestingly, increased blood markers and clinical signs/symptoms were associated with the lowest frequency of true-positive findings (1/66 and 1/10, respectively), while CI findings were confirmed in one third of the cases (13/41). Overall, the incidence of NET in the studied population was 14.5 % (19/131).

CONCLUSION

Our data confirm the good accuracy (98 %) of (68)Ga-DOTA-NOC PET/CT in NET lesion detection. However, our results also suggest that (68)Ga-DOTA-NOC PET/CT may not be routinely recommended in patients with a suspicion of NET based on the mere detection of increased blood markers or clinical symptoms. Positive CI alone or in association with clinical/biochemical findings is on the contrary associated with a higher probability of true-positive findings.

Risk for gastric neoplasias in patients with chronic atrophic gastritis: A critical reappraisal

Chronic atrophic gastritis (CAG) is an inflammatory condition characterized by the loss of gastric glandular structures which are replaced by connective tissue (non-metaplastic atrophy) or by glandular structures inappropriate for location (metaplastic atrophy). Epidemiological data suggest that CAG is associated with two different types of tumors: Intestinal-type gastric cancer (GC) and type I gastric carcinoid (TIGC). The pathophysiological mechanisms which lead to the development of these gastric tumors are different. It is accepted that a multistep process initiating from Helicobacter pylori-related chronic inflammation of the gastric mucosa progresses to CAG, intestinal metaplasia, dysplasia and, finally, leads to the development of GC. The TIGC is a gastrin-dependent tumor and the chronic elevation of gastrin, which is associated with CAG, stimulates the growth of enterochromaffin-like cells with their hyperplasia leading to the development of TIGC. Thus, several events occur in the gastric mucosa before the development of intestinal-type GC and/or TIGC and these take several years. Knowledge of CAG incidence from superficial gastritis, its prevalence in different clinical settings and possible risk factors associated with the progression of this condition to gastric neoplasias are important issues. This editorial intends to provide a brief review of the main studies regarding incidence and prevalence of CAG and risk factors for the development of gastric neoplasias.