Chromogranin A as a valid marker in oncology: Clinical application or false hopes?

Assessment of response to PRRT including anatomical and molecular imaging as well as novel biomarkers

Peptide receptor radionuclide therapy (PRRT) is an effective treatment for both oncological and hormone control and is a widely accepted standard of care treatment for patients with neuroendocrine neoplasms (NEN). Its use is anticipated to increase significantly, and this demands accurate tools and paradigms to assess treatment response post PRRT. This article outlines the current role and future developments of anatomical, molecular imaging and biomarkers for response assessment to PRRT, highlighting the challenges and provides perspectives for the need to focus on a multimodality, multidisciplinary and individualised approach for patients with this complex heterogeneous disease.

Diagnostic challenges in calcitonin negative medullary thyroid carcinoma: a systematic review of 101 cases

Background

Calcitonin-negative medullary thyroid carcinoma (CNMTC), a rare form of MTC characterized by classic histopathology with normal serum calcitonin levels, presents a diagnostic challenge. This systematic review aims to summarize the clinical and pathological features of CNMTC and evaluate the utility of alternative biochemical markers.

Methods

Eligibility criteria for this systematic review included patients with a confirmed histopathological diagnosis of medullary thyroid carcinoma (MTC), normal preoperative serum calcitonin levels, or negative immunohistochemical (IHC) stain for calcitonin. A comprehensive electronic search strategy was employed on PubMed, Scopus, and Embase databases from January 1st, 1950, to March 9th, 2023.

Results

This systematic review consists of 32 studies with 101 patients (66% females, 33% males) with a mean age of 52.2 years. All patients had a preoperative serum calcitonin level below the upper reference limit. Out of 101 patients, only seven underwent the Pentagastrin Stimulation Test (PST), only two patients had elevated calcitonin levels after stimulation. A total of 59 patients were tested for carcinoembryonic antigen (CEA) levels, and the majority tested normal (n=51, 86.4%). A total of 57 patients (61.2%) were found to have positive IHC staining on operative specimens for calcitonin. No recurrence was reported in the majority of cases, only 10 patients (9.9%) experienced recurrence.

Conclusions

Despite the rarity of CNMTC, it is crucial to maintain a high level of suspicion when evaluating thyroid nodules. Total thyroidectomy with central neck dissection remains as the primary treatment. A multimarker approach may improve the sensitivity and specificity of CNMTC diagnosis and surveillance, particularly when calcitonin and CEA levels are inconclusive.

Searching for New Biomarkers of Neuroendocrine Tumors: A Comparative Analysis of Chromogranin A and Inflammatory Cytokines in Patients with Neuroendocrine Tumors

Neuroendocrine neoplasms (NENs) present a diagnostic challenge due to their heterogeneous nature and non-specific clinical manifestations. This study aimed to explore novel biomarkers for NENs. Serum chromogranin A (CgA) levels and a panel of 48 inflammatory cytokines were analyzed in a cohort of 84 NEN patients and 40 healthy controls using enzyme-linked immunosorbent assay (ELISA) and multiplex ELISA. Significant alterations in cytokine levels were observed in the NEN patients compared to the controls, including elevated levels of pro-inflammatory cytokines, such as interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNF-α), and reduced levels of angiogenic factors like platelet-derived growth factor-BB (PDGF-BB) and tumor necrosis factor beta (TNF-β). Notably, cytokines such as growth-regulated alpha protein (GRO-α) and TNF-β demonstrated strong potential as diagnostic markers, with receiver operating characteristic (ROC) curve analyses showing high sensitivity and specificity. Additionally, a positive correlation was found between CgA levels and several inflammatory cytokines, suggesting their synergistic role in tumor progression. These findings highlight the limited reliability of CgA alone as a diagnostic marker and underscore the importance of a multi-marker approach in diagnosing and monitoring NENs. Further research on a larger cohort is necessary to validate these biomarkers and their potential clinical applications.

Metastatic merkel cell carcinoma to the thyroid gland: Case report and review of the literature

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive and rare neuroendocrine tumor, accounting for less than 1% of skin cancers. Metastasis primarily manifests in the cervical lymph nodes but rarely affect the thyroid.

METHODS

We report a case of primary head and neck cutaneous MCC with metastasis to the thyroid gland. A review of the literature of MCC with thyroid metastasis was conducted.

RESULTS

We identified five cases of MCC with thyroid metastasis. Primary sites included the distal upper and lower extremities, axilla, buttock, and groin. Treatment courses varied including thyroidectomy, immunotherapy, and expectant palliative measures. Time from initial diagnosis to thyroid metastasis ranged from four months to four years. Tissue diagnosis was achieved in 5 of 6 cases.

CONCLUSIONS

MCC with thyroid metastasis is rare and likely represents aggressive disease. Despite advances in treatment and surveillance, outcomes for MCC remain poor. Ongoing research may establish predictors for treatment response.

Holistic exploration of CHGA and hsa-miR-137 in colorectal cancer via multi-omic data Integration

Colorectal cancer (CRC) ranks among the most widespread malignancies globally, with early detection significantly influencing prognosis. Employing a systems biology approach, we aimed to unravel the intricate mRNA-miRNA network linked to CRC pathogenesis, potentially yielding diagnostic biomarkers. Through an integrative analysis of microarray, Bulk RNA-seq, and single-cell RNA-seq data, we explored CRC-related transcriptomes comprehensively. Differential gene expression analysis uncovered crucial genes, while Weighted Gene Co-expression Network Analysis (WGCNA) identified key modules closely linked to CRC. Remarkably, CRC manifested its strongest correlation with the turquoise module, signifying its pivotal role. From the cohort of genes showing high Gene Significance (GS) and Module Membership (MM), and Differential Expression Genes (DEGs), we highlighted the downregulated Chromogranin A (CHGA) as a notable hub gene in CRC. This finding was corroborated by the Human Protein Atlas database, which illustrated decreased CHGA expression in CRC tissues. Additionally, CHGA displayed elevated expression in primary versus metastatic cell lines, as evidenced by the CCLE database. Subsequent RT-qPCR validation substantiated the marked downregulation of CHGA in CRC tissues, reinforcing the significance of our differential expression analysis. Analyzing the Space-Time Gut Cell Atlas dataset underscored specific CHGA expression in epithelial cell subclusters, a trend persisting across developmental stages. Furthermore, our scrutiny of colon and small intestine Enteroendocrine cells uncovered distinct CHGA expression patterns, accentuating its role in CRC pathogenesis. Utilizing the WGCNA algorithm and TargetScan database, we validated the downregulation of hsa-miR-137 in CRC, and integrated assessment highlighted its interplay with CHGA. Our findings advocate hsa-miR-137 and CHGA as promising CRC biomarkers, offering valuable insights into diagnosis and prognosis. Despite proteomic analysis yielding no direct correlation, our multifaceted approach contributes comprehensive understanding of CRC's intricate regulatory mechanisms. In conclusion, this study advances hsa-miR-137 and CHGA as promising CRC biomarkers through an integrated analysis of diverse datasets and network interactions.

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.

Improving outcomes in carcinoid heart disease - learning from a single centre

INTRODUCTION

A significant proportion of patients with carcinoid syndrome develop carcinoid heart disease (CHD). Valve degeneration can lead to right heart failure, and worsening prognosis. Replacement of affected valves is an effective therapy. We reviewed patients treated with valve replacement to assess prognostic factors.

METHODS

CHD patients records who underwent valve replacement from 2003-2019 were reviewed.

RESULTS

Twenty-six patients underwent valve replacement. Mean (SD) age was 61 (11) years, 54% female. Eleven tumours were grade G1, with the remaining G2. NYHA pre-surgery mean (SD) 2.0 (0.7); post-surgery mean 1.2; follow-up mean (SD) 1.6 (0.8). Mean NYHA score difference from pre- to post-surgery -0.71 ( P  = 0.002). 88.5% two (PR & TR), 3.9% one, 3.9% three and 3.9% four valves replaced. 13 patients received Lu177 oxodotreotide; 27% completed four cycles. Mortality at 1 and 5 years follow up was 42% and 50% respectively. Cox proportional hazards model of survival from surgery, adjusting for age [hazard ratio (HR) 0.96 (0.89-1.03) ( P  = 0.25)], four cycles of Lu177 oxodotreotide demonstrated HR 0.087 (0.0079-0.95) ( P  = 0.045) indicating improved survival.

DISCUSSION

Surgical patients were often NYHA grade II, and symptoms improved post-surgery. Four cycles of Lu177 oxodotreotide improved survival, although the confidence interval was wide. Further studies should be performed to assess Lu177 oxodotreotide in CHD.

A Case of Functional Bowel Disease Misdiagnosed as Carcinoid Syndrome

An elevated urinary 5-hydroxyindoleacetic acid (U5-HIAA) is typically thought of to be related to carcinoid syndrome. It is widely known that several other etiologies can cause high levels; however, those etiologies typically cause mild elevations. We present a unique situation of a highly elevated U5-HIAA not because of a neuroendocrine tumor. Gastroenterologists need to have an approach in mind if they encounter this predicament. We aim to raise awareness of this situation to emphasize the importance of a thorough medication history and avoid unnecessary testing.

An Overview of Circulating Biomarkers in Neuroendocrine Neoplasms: A Clinical Guide

Neuroendocrine neoplasms (NENs) are a heterogeneous group of diseases that are characterized by different behavior and clinical manifestations. The diagnosis and management of this group of tumors are challenging due to tumor complexity and lack of precise and widely validated biomarkers. Indeed, the current circulating mono-analyte biomarkers (such as chromogranin A) are ineffective in describing such complex tumors due to their poor sensitivity and specificity. In contrast, multi-analytical circulating biomarkers (including NETest) are emerging as more effective tools to determine the real-time profile of the disease, both in terms of accurate diagnosis and effective treatment. In this review, we will analyze the capabilities and limitations of different circulating biomarkers focusing on three relevant questions: (1) accurate and early diagnosis; (2) monitoring of disease progression and response to therapy; and (3) detection of early relapse.

Dynamic assessment of serum chromogranin A and treatment response with abiraterone acetate in metastatic castration-resistant prostate cancer

OBJECTIVE

Elevated serum chromogranin A (CGA) is associated with intrinsic or treatment-related neuroendocrine differentiation (NED) in men with metastatic castration-resistant prostate cancer (mCRPC). Fluctuations in serum CGA during treatment of mCRPC have had conflicting results. We analyzed the impact of (i) rising serum CGA and (ii) baseline CGA/PSA ratio during treatment to identify associations with abiraterone acetate (AA) therapy.

METHODS

Between June 2013 and August 2015, 92 men with mCRPC were enrolled in a prospective trial with uniform serum CGA processing performed before initiating abiraterone acetate/prednisone (AA/P) and serially after 12 weeks of AA/P treatments. Serum CGA was measured using a homogenous automated immunofluorescent assay. Patients receiving proton pump inhibitors or with abnormal renal function were excluded due to possible false elevations of serum CGA (n = 21 excluded), therefore 71 patients were analyzed. All patients underwent a composite response assessment at 12-weeks. Kaplan-Meier estimates and Cox Regression models were used to calculate the association with time-to-treatment failure analyses and overall survival.

RESULTS

An increase in chromogranin was associated with a lower risk of treatment failure (hazard ratio [HR]: 0.52, p = 0.0181). The median CGA/PSA ratio was 7.8 (2.6-16.0) and an elevated pretreatment CGA/PSA ratio above the median was associated with a lower risk of treatment failure (HR: 0.54 p value = 0.0185). An increase in CGA was not found to be associated with OS (HR: 0.71, 95% CI: 0.42-1.21, p = 0.207). An elevated baseline CGA/PSA ratio was not associated with OS (HR: 0.62, 95% CI: 0.37-1.03, p = 0.062). An increase in PSA after 12 weeks of treatment was associated with an increased risk of treatment failure (HR: 4.14, CI: 2.21-7.73, p = < 0.0001) and worse OS (HR: 2.93, CI: 1.57-4.45, p = < 0.0001).

CONCLUSIONS

We show that an increasing chromogranin on AA/P and an elevated baseline CGA/PSA in patients with mCRPC were associated with a favorable response to AA/P with no changes in survival. There may be limited clinical utility in serum CGA testing to evaluate for lethal NED as AA/P did not induce lethal NED in this cohort. This highlights that not all patients with an increasing CGA have a worse OS.

Radiofrequency ablation for the management of pancreatic mass lesions

PURPOSE OF REVIEW

Patients with pancreatic tumors may have limited treatment options. Pancreatic tumor ablation is a novel and emerging treatment modality which can now be performed using endoscopic ultrasound (EUS) guidance. This modality is well suited to guide energy delivery for radiofrequency ablation (RFA) and microwave ablation. These approaches provide minimally invasive, nonsurgical methods for delivering energy to ablate pancreatic tumors in situ. This review summarizes the current data and safety profile for ablation in managing pancreatic cancer and pancreatic neuroendocrine tumors.

RECENT FINDINGS

RFA uses thermal energy to induce cell death by coagulative necrosis and protein denaturation. Studies have reported increased overall survival in patients with pancreatic tumors treated with EUS-guided RFA in a multimodality systemic approach and when used in palliative surgeries. Radiofrequency ablation may have corollary benefits in inducing an immune-modulatory effect. Tumor marker carbohydrate antigen 19-9 has been reported to decrease in response to RFA. Microwave ablation is an emerging modality.

SUMMARY

RFA utilizes focal thermal energy to induce cell death. RFA has been applied through open, laparoscopic, and radiographic modalities. EUS-guided approaches are now allowing RFA and microwave ablation to be performed for pancreatic tumors in situ.

Pitfalls in the Diagnosis and Management of Hypercortisolism (Cushing Syndrome) in Humans; A Review of the Laboratory Medicine Perspective

Biochemical confirmation of a diagnosis of hypercortisolism (Cushing syndrome) is vital to direct further investigations, especially given the overlap with non-autonomous conditions, such as pseudo-Cushing, and the morbidity associated with missed diagnoses. A limited narrative review was performed focusing on the laboratory perspective of the pitfalls of making a biochemical diagnosis of hypercortisolism in those presenting with presumed Cushing syndrome. Although analytically less specific, immunoassays remain cheap, quick, and reliable in most situations. Understanding cortisol metabolism can help with patient preparation, specimen selection (e.g., consideration of urine or saliva for those with possible elevations of cortisol binding globulin concentration), and method selection (e.g., mass spectrometry if there is a high risk of abnormal metabolites). Although more specific methods may be less sensitive, this can be managed. The reduction in cost and increasing ease of use makes techniques such as urine steroid profiles and salivary cortisone of interest in future pathway development. In conclusion, the limitations of current assays, particularly if well understood, do not impede diagnosis in most cases. However, in complex or borderline cases, there are other techniques to consider to aid in the confirmation of hypercortisolism.

Targeting PKLR/MYCN/ROMO1 signaling suppresses neuroendocrine differentiation of castration-resistant prostate cancer

Conventional treatment of prostate cancer (PCa) uses androgen-deprivation therapy (ADT) to inhibit androgen receptor (AR) signaling-driven tumor progression. ADT-induced PCa recurrence may progress to an AR-negative phenotype with neuroendocrine (NE) histologic features, which are associated with metabolic disturbances and poor prognoses. However, the metabolic pathways that regulate NE differentiation (NED) in PCa remain unclear. Herein, we show a regulatory mechanism in NED-associated metabolism dysfunction induced by ADT, whereby overexpression of pyruvate kinase L/R (PKLR) mediates oxidative stress through upregulation of reactive oxygen species modulator 1 (ROMO1), thereby promoting NED and aggressiveness. ADT mediates the nuclear translocation of PKLR, which binds to the MYCN/MAX complex to upregulate ROMO1 and NE-related genes, leading to altered mitochondrial function and NED of PCa. Targeting nuclear PKLR/MYCN using bromodomain and extra-terminal motif (BET) inhibitors has the potential to reduce PKLR/MYCN-driven NED. Abundant ROMO1 in serum samples may provide prognostic information in patients with ADT. Our results suggest that ADT resistance leads to upregulation of PKLR/MYCN/ROMO1 signaling, which may drive metabolic reprogramming and NED in PCa. We further show that increased abundance of serum ROMO1 may be associated with the development of NE-like PCa.

Gastrointestinal Neuroendocrine Tumours: A Single-Centre Experience

Objectives

Gastrointestinal neuroendocrine tumours (GI-NETs) are actually malignant tumours, and their most common location of metastasis is the liver. In this study, we define the epidemiologic features of NETs and investigate the demographic factors, clinicopathologic features, survival, and the oncologic results related to GI-NETs.

Materials and Methods

In this 10-year study (2009–2019), all GI and liver NETs were taken out from the pathology records. When classification based on the WHO classification criteria, patients were categorized based on their location, sex, age, and proliferative index. After studying clinical charts of GI-NET cases, a complete panel of IHC markers such as Chromogranin A, ‘Ki67’ and synaptophysin were used. Results: Based on published data, the liver is not a common primary site for NETs; most liver lesions are most likely to have been metastases. The mean age of patients at diagnosis was 52.72 years. In this research, 27.78% of patients had colon NETs and 27.78 liver. Two (11.11%) patients were classified as stage II, seven (38.89%) as stage III, and one (5.56%) as stage IV. After a 120-month follow-up, 13 (72.22%) patients with colorectal NETs were alive, and 5 (27.78%) of the patients had died.

Conclusion

Treatment of colon and rectal NETs is difficult because it affects the patient's initial site of involvement, and this often makes treatment difficult for the patient. With suitable management, the prognosis can be positive with long survival, but it is related to the tumour variation grade, the efficiency of the selected treatment, and also to the patient's adherence to the follow-up.

Clinical activity of CC-90011, an oral, potent, and reversible LSD1 inhibitor, in advanced malignancies

Background

CC‐90011 is an oral, potent, selective, reversible inhibitor of lysine‐specific demethylase 1 (LSD1) that was well tolerated, with encouraging activity in patients who had advanced solid tumors or relapsed/refractory marginal zone lymphoma. The authors present long‐term safety and efficacy and novel pharmacodynamic and pharmacokinetic data from the first‐in‐human study of CC‐90011.

Methods

CC‐90011‐ST‐001 (ClincalTrials.gov identifier NCT02875223; Eudract number 2015–005243‐13) is a phase 1, multicenter study in which patients received CC‐90011 once per week in 28‐day cycles. The objectives were to determine the safety, maximum tolerated dose, and/or recommended phase 2 dose (primary) and to evaluate preliminary efficacy and pharmacokinetics (secondary).

Results

Sixty‐nine patients were enrolled, including 50 in the dose‐escalation arm and 19 in the dose‐expansion arm. Thrombocytopenia was the most common treatment‐related adverse event and was successfully managed with dose modifications. Clinical activity with prolonged, durable responses were observed, particularly in patients who had neuroendocrine neoplasms. In the dose‐escalation arm, one patient with relapsed/refractory marginal zone lymphoma achieved a complete response (ongoing in cycle 58). In the dose‐expansion arm, three patients with neuroendocrine neoplasms had stable disease after nine or more cycles, including one patient who was in cycle 46 of ongoing treatment. CC‐90011 decreased levels of secreted neuroendocrine peptides chromogranin A, progastrin‐releasing peptide, and RNA expression of the blood pharmacodynamic marker monocyte‐to‐macrophage differentiation–associated.

Conclusions

The safety profile of CC‐90011 suggested that its reversible mechanism of action may provide an advantage over other irreversible LSD1 inhibitors. The favorable tolerability profile, clinical activity, durable responses, and once‐per‐week dosing support further exploration of CC‐90011 as monotherapy and in combination with other treatments for patients with advanced solid tumors and other malignancies.

This first‐in‐human study evaluated CC‐90011, a highly potent, selective, and reversible oral lysine‐specific demethylase 1 inhibitor, in patients with advanced solid tumors and relapsed/refractory lymphoma. The tolerability, clinical activity, and once‐weekly dosing support further exploration of CC‐90011 in patients with advanced malignancies.

Gastric and Duodenal Neuroendocrine Tumor Incidentally Found on Endoscopy During the Evaluation of Iron-Deficiency Anemia

Neuroendocrine tumors (NET) are a small fraction of overall gastrointestinal (GI) malignancies. Recently the incidence of NETs has increased due to advancements in diagnostic modality. While solid tumors are easily visible on routine endoscopy, identifying endocrine tumors can be difficult, and low incidence and non-specific presentation can be easily missed on upper gastrointestinal endoscopy (UGIE). The management differs based on the type of tumor and location, but the overall prognosis is good. We present a 59-year-old male with multiple NETs throughout the GI tract, diagnosed on repeat esophagogastroduodenoscopy (EGD) with endoscopic ultrasound (EUS) showing multiple gastric folds. A biopsy of multiple nodules was taken to diagnose type I NET with grade 2 differentiation finally. The mucosal nodules were resected with a band ligator, and surveillance endoscopy was recommended.

Perspectives on the diagnostic, predictive and prognostic markers of neuroendocrine neoplasms (Review)

Neuroendocrine neoplasms (NENs) are a heterogeneous group of rare tumors with different types of physiology and prognosis. Therefore, prognostic information, including morphological differentiation, grade, tumor stage and primary location, are invaluable and contribute to the formulation of treatment decisions. Biomarkers that are currently used, including chromogranin A (CgA), serotonin and neuron-specific enolase, are singular parameters that cannot be used to accurately predict variables associated with tumor growth, including proliferation, metabolic rate and metastatic potential. In addition, site-specific biomarkers, such as insulin and gastrin, cannot be applied to all types of NENs. The clinical application of broad-spectrum markers, as it is the case for CgA, remains controversial despite being widely used. Due to limitations of the currently available mono-analyte biomarkers, recent studies were conducted to explore novel parameters for NEN diagnosis, prognosis, therapy stratification and evaluation of treatment response. Identification of prognostic factors for predicting NEN outcome is a critical requirement for the planning of adequate clinical management. Advances in ‘liquid’ biopsies and genomic analysis techniques, including microRNA, circulating tumor DNA or circulating tumor cells and sophisticated biomathematical analysis techniques, such as NETest or molecular image-based biomarkers, are currently under investigation as potentially novel tools for the management of NENs in the future. Despite these recent findings yielding promising observations, further research is necessary. The present review therefore summarizes the existing knowledge and recent advancements in the exploration of biochemical markers for NENs, with focus on gastroenteropancreatic-neuroendocrine tumors.

Significance of chromogranin A and synaptophysin in medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare thyroid carcinoma of C-cell deviation that produces and secretes calcitonin (CT) and chromogranin A (CgA) into the blood. Thus, CT and CgA are immunohistochemical and serum markers for MTCs. MTC occurs in sporadic and inheritable forms. The hallmark of inheritable cases in multiple endocrine neoplasm 2 (MEN2) is MTC. MEN2 cases represent 30% through germline RET proto-oncogene mutation and occur in younger ages involving bilateral thyroid lobes. Sporadic cases are 70% and occur in older ages. CgA and synaptophysin (SPY) are the two most widely used and reliable immunohistochemical markers for neuroendocrine tumors, including MTCs. This study aimed to detect different immunohistochemical staining patterns for CgA and SPY between non-symptomatic small lesions and invading larger aggressive tumors in both MEA2 cases and sporadic cases. There was different CgA and SPY immunostaining in MEA2 cases where small tumors (≤0.3 cm) were lesser immunostained for CgA and SPY, despite intense staining for CT, compared to the larger (≥0.5 cm) tumors, stronger immunostained for CgA. There was also different CgA and SPY immunohistochemical staining in sporadic cases between small lesions (≤0.5 cm) and larger tumors (≥1.0 cm). One small sporadic tumor (0.5 cm × 0.3 cm) was strongly and weakly, patchy stained for CgA and SPY, respectively, while larger sporadic tumors were diffusely and strongly stained for CgA and SPY. Therefore, stronger CgA and SPY immunostaining for larger tumors in both MEA2 and sporadic cases may be used as independent, aggressive immunohistochemical markers for MTCs.

Primary Small Cell Carcinoma of the Bladder

A 64-year-old Caucasian man with a 20 to 25-pack-year cigarette smoking history presented to his primary care provider with the chief complaint of gross hematuria after experiencing three to four months of urinary frequency and urgency. His workup consisted of laboratory blood work, a renal/bladder ultrasound (US), a CT scan without contrast, cystoscopy with biopsy (with an attempted transurethral resection of bladder tumor), and a PET scan. He was diagnosed with stage T4 small cell carcinoma of the bladder (SCCB) shortly after seeking medical care with metastases to the liver, bone, and lymph nodes. There was no evidence of lung involvement. The patient's primary concerns included difficulty urinating and sustained hematuria. He underwent palliative radiotherapy and placement of bilateral nephrostomy tubes in order to preserve his quality of life. He also received a chemotherapy regimen consisting of cisplatin, etoposide, and atezolizumab. The patient underwent hospice care and died approximately six months after the presentation.

Parathyroid cancer: A systematic review of diagnostic biomarkers

INTRODUCTION

Parathyroid cancers are rare and difficult to distinguish from benign parathyroid tumours. Prediction of malignancy often relies on intraoperative assessment of invasion. Standard histology is also inadequate; especially in the absence of local invasion, lymph nodal disease and metastasis. The aim of this project was to systematically review published literature on potential bio-markers used for the diagnosis of parathyroid cancer.

METHODS

Pubmed, Web of Science and Medline databases were searched. Inclusion criteria included English language papers published after 1985 and reporting on biomarkers in human studies of parathyroid cancer and benign disease.

RESULTS

118 relevant papers were appraised; all were observational studies. At least 2 papers studied 8 serum, 4 urine and 27 tissue biomarkers on the diagnosis of parathyroid cancer. Of these, 5 serum and 13 tissue markers have been demonstrated in at least one study to be statistically different in benign and malignant disease. We present a synthesis of data for each biomarker and measures of diagnostic accuracy where possible.

CONCLUSIONS

Consideration should be given to the use of a panel of biomarkers to review patients with suspected parathyroid cancer. A profile including serum calcium and PTH levels and tissue expression of APC, Parafibromin, PGP9.5, Galectin 3 and Ki67 is proposed. Systematic Review Registration Number - CRD42019127833.

NETest is superior to chromogranin A in neuroendocrine neoplasia: a prospective ENETS CoE analysis

INTRODUCTION

The absence of a reliable, universal biomarker is a significant limitation in neuroendocrine neoplasia (NEN) management. We prospectively evaluated two CgA assays, (NEOLISA, EuroDiagnostica) and (CgA ELISA, Demeditec Diagnostics (DD)) and compared the results to the NETest.

METHODS

NEN cohort (n = 258): pancreatic, n = 67; small intestine, n = 40; appendiceal, n = 10; rectal, n = 45; duodenal, n = 9; gastric, n = 44; lung, n = 43. Image-positive disease (IPD) (n = 123), image & histology- negative (IND) (n = 106), and image-negative and histology positive (n = 29). CgA metrics: NEOLISA, ULN: 108 ng/mL, DD: ULN: 99 ng/mL. Data mean ± s.e.m. NETest: qRT-PCR - multianalyte analyses, ULN: 20. All samples de-identified and assessed blinded. Statistics: Mann-Whitney U-test, Pearson correlation and McNemar-test.

RESULTS

CgA positive in 53/258 (NEOLISA), 32 (DD) and NETest-positive in 157/258. In image- positive disease (IPD, n = 123), NEOLISA-positive: 33% and DD: 19%. NETest-positive: 122/123 (99%; McNemar's Chi2= 79-97, P < 0.0001). NEOLISA was more accurate than DD (P = 0.0003). In image- negative disease (IND), CgA was NEOLISA-positive (11%), DD (8%), P = NS, and NETest (33%). CgA assays could not distinguish progressive (PD) from stable disease (SD) or localized from metastatic disease (MD). NETest was significantly higher in PD (47 ± 5) than SD (29 ± 1, P = 0.0009). NETest levels in MD (35 ± 2) were elevated vs localized disease (24 ± 1.3, P = 0.008).

CONCLUSIONS

NETest, a multigenomic mRNA biomarker, was ~99% accurate in the identification of NEN disease. The CgA assays detected NEN disease in 19-33%. Multigenomic blood analysis using NETest is more accurate than CgA and should be considered the biomarker standard of care.

Appendectomy Should Be Performed During Minimally Invasive Surgery for Endometriosis

OBJECTIVES

To determine the prevalence of appendiceal histopathology in patients with confirmed endometriosis following minimally invasive surgery (MIS) for endometriosis. To determine whether pre-operative symptoms, age, intra-operative appendiceal appearance, or endometrioma laterality were associated with appendix histopathology in patients with suspected endometriosis.

METHODS

One hundred thirty-five patients ages 16-52 with suspected endometriosis undergoing MIS for endometriosis with concomitant appendectomy at two metropolitan academic hospitals from January 1, 2012 to June 30, 2017 were included in this retrospective chart-review study. Medical records were reviewed for pre-operative symptoms, age, intraoperative appendix appearance, appendix histopathology, histopathologically-confirmed endometriosis, and endometriomas.

RESULTS

In patients with confirmed endometriosis, the prevalence of all appendiceal histopathology was 25%, which included appendiceal endometriosis (18%), appendiceal tumors (2%), and inflammation (5%). Dyspareunia was the only pre-operative symptom significantly associated with appendiceal histopathology (p = 0.04). The presence of a right endometrioma was associated with appendiceal histopathology (p = 0.009). Additionally, appendiceal histopathology was not significantly associated with age nor intra-operative appendiceal characteristics.

CONCLUSION

This manuscript adds to the limited pool of studies regarding appendiceal histopathology and appendiceal tumors in patients with suspected and confirmed endometriosis. On the basis of the high rate of histopathological appendices found in this population; the lack of association with possible diagnostic factors such as age, most pre-operative symptoms, and intra-operative appendiceal characteristics; and the relatively low risks of concomitant appendectomy, we suggest that surgeons consider concomitant appendectomies at the time of MIS for endometriosis.

Circulating miRNA Increases the Diagnostic Accuracy of Chromogranin A in Metastatic Pancreatic Neuroendocrine Tumors

Simple Summary

Despite its varying sensitivity and decreased specificity, chromogranin A (CgA) is the most widely used biomarker for neuroendocrine tumors. The most common factor affecting its diagnostic accuracy is the use of proton pump inhibitors (PPIs). Our aim was to investigate circulating miRNA expression profiles in pancreatic neuroendocrine tumors (pNET) and pheochromocytomas/paragangliomas (PPGL) to find miRNAs which could be used as biomarkers along with CgA in these patients. MiRNA expression profiles were determined with next generation sequencing and validated by quantitative real time PCR in 74 samples obtained from patients and healthy volunteers treated with PPI. We observed a global downregulation of miRNAs in NET compared to controls. A set of miRNAs in combination with CgA resulted in the best discrimination of pNET irrespective of PPI treatment and a combination of miRNAs increased the diagnostic utility of CgA even in pNET patients with low CgA.

Abstract

Chromogranin A (CgA) is the most widely accepted biomarker for neuroendocrine tumors (NET) but its diagnostic accuracy is dependent on tumor type and the use of proton-pump inhibitors (PPI). We investigated the diagnostic value of circulating miRNAs along with CgA in pancreatic neuroendocrine tumors (pNET). 74 serum samples from patients with pNET (n = 25, nonfunctioning), pheochromocytoma/paraganglioma (PPGL, n = 20), healthy individuals with normal CgA (n = 29) including 10 samples from 5 healthy individuals with and without current PPI treatment were collected. MiRNA expression profiles were determined using next-generation sequencing, followed by validation with individual TaqMan assays. A global downregulation of miRNAs was observed in patients with NET compared to controls. MiRNA expression of 33 miRNAs was able to discriminate tumor samples from controls. No miRNA alone could be considered as an applicable biomarker for pNET or PPGL. However, using a logistic model, the combination of a set of miRNAs increased the discriminatory role of CgA irrespective of PPI treatment. In pNET patients with normal CgA level our regression model yielded high (89.4%) diagnostic accuracy (AUC: 0.904, sensitivity: 66.6%, specificity: 96.5%). A set of miRNAs increased the diagnostic utility of CgA in pNET even in patients with low CgA.

Significance of chromogranin A and synaptophysin in pancreatic neuroendocrine tumors

The two most commonly used immunohistochemical markers for neuroendocrine cells and their tumors are chromogranin A (CgA) and synaptophysin (SPY). CgA is a marker for neuroendocrine secretory granules of four pancreatic hormones and gastrin while SPY is a marker for synaptic vesicles in neuroendocrine cells, which release classic neurotransmitters such as acetylcholine and others. CgA is involved in synthesis and secretion of peptide hormones through exocytosis while the function of SPY is elusive. Thirty-five pancreatic neuroendocrine tumors (Pan-NETs) were studied, consisting of 14 insulinomas, 8 gastrinomas, 2 glucagonomas, 6 pancreatic polypeptidomas and 5 non-functioning tumors, and were immunostained for four pancreatic hormones, gastrin, CgA, and SPY. Majority of Pan-NETs were less immunostained for the endocrine hormones and CgA than the normal pancreatic endocrine cells. CgA immunostaining mostly correlates with each hormone staining in non-β-cell tumors, while SPY immunostaining recognizes endocrine cells diffusely in the cytoplasm. CgA immunostaining is less in insulinomas than in non-β-cell tumors, and CgA immunostaining may distinguish CgA-weaker insulinomas from CgA-stronger non-β-cell tumors. CgA immunostaining may be used as an independent marker for biological aggressiveness in non-β-cell Pan-NETs. The serum CgA levels are higher in subjects harboring non-β-cell tumors than those harboring insulinomas, and the serum CgA elevates in parallel to the increasing metastatic tumor mass. Thus, CgA positive immunostaining in Pan-NETs correlates with the elevated serum levels of CgA for diagnosing CgA-positive non-β-cell Pan-NETs and the increasing serum CgA levels indicate increasing metastatic tumor mass.

The North American Neuroendocrine Tumor Society Consensus Guidelines for Surveillance and Medical Management of Pancreatic Neuroendocrine Tumors

This article is the result of the North American Neuroendocrine Tumor Society consensus conference on the medical management of pancreatic neuroendocrine tumors from July 19 to 20, 2018. The guidelines panel consisted of medical oncologists, pathologists, gastroenterologists, endocrinologists, and radiologists. The panel reviewed a series of questions regarding the medical management of patients with pancreatic neuroendocrine tumors as well as questions regarding surveillance after resection. The available literature was reviewed for each of the question and panel members voted on controversial topics, and the recommendations were included in a document circulated to all panel members for a final approval.

Carcinoid Syndrome: A Review

Carcinoid syndrome (CS) is a paraneoplastic syndrome caused by the release of serotonin and other substances from well-differentiated neuroendocrine tumors (NETs). The hallmark symptoms of carcinoid syndrome are flushing and diarrhea; atypical signs and symptoms can include wheezing, abdominal pain, valvular heart disease, telangiectasias, pellagra, and the complications of mesenteric fibrosis, including ureteral obstruction, bowel obstruction, and bowel ischemia. These symptoms are mediated by the release of serotonin (5-HT), histamine, kallikrein, prostaglandins, and tachykinins. The diagnosis of CS requires these symptoms and corresponding elevations in lab tests. Treatment options include surgery and medical management with somatostatin analogs.

An Assessment of Circulating Chromogranin A as a Biomarker of Bronchopulmonary Neuroendocrine Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND

Management of bronchopulmonary neuroendocrine neoplasia (NEN; pulmonary carcinoids [PCs], small-cell lung cancer [SCLC], and large cell neuroendocrine carcinoma) is hampered by the paucity of biomarkers. Chromogranin A (CgA), the default neuroendocrine tumor biomarker, has undergone wide assessment in gastroenteropancreatic neuroendocrine tumors.

OBJECTIVES

To evaluate CgA in lung NEN, define its clinical utility as a biomarker, assess its diagnostic, prognostic, and predictive efficacy, as well as its accuracy in the identification of disease recurrence.

METHODS

A systematic review of PubMed was undertaken using the preferred reporting items for systematic reviews and meta-analyses guidelines. No language restrictions were applied. Overall, 33 original scientific papers and 3 case reports, which met inclusion criteria, were included in qualitative analysis, and meta-analysis thereafter. All studies, except 2, were retrospective. Meta-analysis statistical assessment by generic inverse variance methodology.

RESULTS

Ten different CgA assay types were reported, without consistency in the upper limit of normal (ULN). For PCs (n = 16 studies; median patient inclusion 21 [range 1-200, total: 591 patients]), the CgA diagnostic sensitivity was 34.5 ± 2.7% with a specificity of 93.8 ± 4.7. CgA metrics were not available separately for typical or atypical carcinoids. CgA >100 ng/mL (2.7 × ULN) and >600 ng/mL (ULN unspecified) were anecdotally prognostic for overall survival (n = 2 retrospective studies). No evidence was presented for predicting treatment response or identifying post-surgery residual disease. For SCLC (n = 19 studies; median patient inclusion 23 [range 5-251, total: 1,241 patients]), the mean diagnostic sensitivity was 59.9 ± 6.8% and specificity 79.4 ± 3.1. Extensive disease typically exhibited higher CgA levels (diagnostic accuracy: 61 ± 2.5%). An elevated CgA was prognostic for overall survival (n = 4 retrospective studies). No prospective studies evaluating predictive benefit or prognostic utility were identified.

CONCLUSION

The available data are scarce. An assessment of all published data showed that CgA exhibits major limitations as an effective and accurate biomarker for either PC or SCLC. Its utility especially for localized PC/limited SCLC (when surgery is potentially curative), is limited. The clinical value of CgA remains to be determined. This requires validated, well-constructed, multicenter, prospective, randomized studies. An assessment of all published data indicates that CgA does not exhibit the minimum required metrics to function as a clinically useful biomarker for lung NENs.

A Limited-Versus-Extensive Staging Strategy for Small Cell Prostate Cancer

INTRODUCTION

Small cell prostate cancer (SCPC) is a rare histologic subtype of prostate cancer, for which the optimal staging strategy remains unclear.

METHOD

The Surveillance, Epidemiology, and End Results database was used to analyze the incidence and outcomes of SCPC between the years 2004 through 2016. Limited-stage SCPC (LS-SCPC) was defined as SCPC without any metastasis regardless of local invasion. Extensive stage SCPC (ES-SCPC) was defined as any metastasis to lymph nodes and/or to distant organs.

RESULT

A total of 403 SCPC patients were included in the study cohort, accounting for 0.056% of all prostate cancer cases (n=719,655). Of the 358 patients with known metastasis status, 275 (76.8%) patients had ES-SCPC, whereas 83 (23.2%) patients had LS-SCPC. LS-SCPC was associated with better overall survival (17 vs. 9 mo, P<0.001) and disease-specific survival (25 vs. 10 mo, P<0.001) compared with ES-SCPC. All LS-SCPC patients had a similar overall survival regardless of T stage. Similarly, all ES-SCPC patients had similar outcomes regardless of metastasis sites. High prostate-specific antigen (PSA) is paradoxically associated with superior outcome in both localized stage patients (PSA≥4 vs. PSA<4, 19 vs. 10 mo, P=0.002) and extensive stage patients (PSA≥20 vs. PSA<20, 13 vs. 9 mo, P=0.02). Multivariate analysis of treatment showed that chemotherapy was associated with improved survival in ES-SCPC with hazard ratio of 0.52.

CONCLUSION

Similar to small cell lung cancer, SCPC can be staged into LS-SCPC or ES-SCPC. The binary staging system correlates well with prognosis.

High-soluble CGA levels are associated with poor survival in bladder cancer

Recently, a neuroendocrine-like molecular subtype has been discovered in muscle-invasive urothelial bladder cancer (BC). Chromogranin A (CGA) is a widely used tissue and serum marker in neuroendocrine tumors. Our aim was to evaluate serum CGA (sCGA) concentrations and their associations with clinical and follow-up data in BC and renal cell carcinoma (RCC). sCGA concentrations were analyzed in the following cohorts: (1) BC training set (n = 188), (2) BC validation set (n = 125), (3) RCC patients (n = 77), (4) healthy controls (n = 97). CGA immunohistochemistry and RT-qPCR analyses were performed in 20 selected FFPE and 29 frozen BC tissue samples. Acquired data were correlated with clinicopathological parameters including comorbidities with known effect on sCGA as well as with patients' follow-up data. sCGA levels were significantly higher in BC but not in RCC patients compared to healthy controls. High sCGA levels were independently associated with poor overall and disease-specific survival both in the BC training (P < 0.001, P = 0.002) and validation set (P = 0.009, P = 0.017). sCGA levels were inversely correlated with glomerulus filtrating rate (GFR) and linearly correlated with creatinine clearance and urea concentrations. These correlations were not related to the prognostic value of sCGA. Tissue CGA levels were low to absent independently of sCGA concentrations. Our results demonstrate elevated levels and an independent prognostic value for sCGA in BC but not in RCC. Despite the significant correlation between sCGA and GFR, the prognostic relevance of sCGA seems not related to impaired renal function or other comorbidities.

Paraneoplastic syndromes: Definitions, classification, pathophysiology and principles of treatment

Paraneoplastic syndromes (PNS) are rare clinical syndromes due to the systemic effects of tumours; they are unrelated to tumour size, invasiveness or metastases. Recent years have seen considerable advances leading to improved understanding of their pathophysiology and increased recognition of new PNS entities and PNS associated tumours. While of paramount importance, diagnosis is still frequently missed or delayed. Diverse organs and systems are affected by the associated tumours- which may be benign or malignant. PNS can occur concurrently with tumour diagnosis, before tumour is diagnosed and even after tumours have been resected. Also, there are autoimmune diseases later progressing to PNS when occult tumours are identified. Another confounding factor is that many PNS clinically resemble non-neoplastic diseases. PNS are largely due to two main causes: those due to tumour secretions of hormones, functionally active peptides, enzymes cytokines or to tumours operating through auto-immune/immunological mechanisms with cross-reacting antibodies between neoplastic and normal tissues. Remission of symptoms often follows resection of humoral secretory tumours but not always of tumours due to immunological mechanisms. Classifications schemes vary but most currently place PNS in one of five groups: endocrine, neurological, musculocutaneous, haematological and other. Due to advances both in diagnostic techniques in identifying tumours as well as in therapy, early diagnosis not only results in improved prognosis of both PNS and associated tumours but also enables monitoring response to treatment and early detection of recurrence. This article covers definition, general principals of classification, diagnosis, pathophysiology and treatment, with emphasis on tumour related PNS serving as an introduction to the following articles.

Serum chromogranin-A-based prognosis in metastatic castration-resistant prostate cancer

OBJECTIVE

To determine the prognostic value of serum chromogranin-A (CGA) in a two-cohort study of men with metastatic castrate resistant prostate cancer (mCRPC) and to compare with circulating tumor cells (CTCs)-based prognosis.

PATIENTS AND METHODS

A two-cohort-based evaluation for serum CGA for prognostication in CRPC stage was performed using a screening cohort of 256 men with mCRPC and an independent validation cohort of 92 men with mCRPC. In both cohorts, men receiving proton pump inhibitors and those with non-castrate levels of testosterone (>50 ng/dl) were excluded. Serum CGA was measured in a homogeneous automated immunofluorescent assay using time-resolved amplified cryptate emission. In the validation cohort, CTC enumeration was also performed using the FDA-cleared CELLSEARCH® CTC test. Cox proportional hazard regression models were used for prognostic association of serum CGA and CTC counts with overall survival.

RESULTS

In the screening cohort, 200 men were eligible for analysis. The median serum CGA was 100.3 ng/mL (interquartile range: 67-161.3) and 34/200 were above the reference range. In the subset of men with Gleason scores ≥ 8, elevated CGA was associated with shorter overall survival [hazard ratio (HR) 2.19, p = 0.017]. In the validation cohort for 71 men eligible for analysis, the median serum CGA was 90 ng/mL (interquartile range: 55-156) and 31/71 patients had an elevated CGA. 51% of patients had a Gleason score ≥ 8 and 66/71 patients had CTCs enumerated with 26/66 with a CTC count ≥ 5 per 7.5 ml blood sample (unfavorable). Both elevated serum CGA (HR: 1.91, p = 0.043) and unfavorable CTC counts (HR: 2.97, p = 0.0012) were adversely associated with overall survival and patients with ≥ 5 CTCs and elevated serum CGA had the shortest overall survival (HR: 3.76, p = 0.008).

CONCLUSION

Elevated serum CGA was negatively associated with OS in men with mCRPC. Serum CGA represents a prognostic biomarker that may complement CTC enumeration.

Effective preparation of a monoclonal antibody against human chromogranin A for immunohistochemical diagnosis

BACKGROUND

Human chromogranin A (CgA) is a ~ 49 kDa secreted protein mainly from neuroendocrine cells and endocrine cells. The CgA values in the diagnosis of tumor, and in the potential role in prognostic and predictive tumor as a biomarker.

RESULTS

The synthesized gene of CgA coding area was cloned and expressed as fusion protein CgA-His in procaryotic system. Then the purified CgA-His protein was mixed with QuickAntibody-Mouse5W adjuvant, and injected into mice. The CgA-His protein was also used as coating antigen to determine the antiserum titer. By screening, a stable cell line named 4E5, which can generate anti-CgA monoclonal antibody (mAb), was obtained. The isotype of 4E5 mAb was IgG_2b, and the chromosome number was 102 ± 4. Anti-CgA mAb was purified from ascites fluid, and the affinity constant reached 9.23 × 10⁹ L/mol. Furthermore, the specificity of the mAb was determined with ELISA, western blot and immunohistochemistry. Results indicated that the mAb 4E5 was able to detect chromogranin A specifically and sensitively.

CONCLUSIONS

A sensitive and reliable method was successfully developed for rapid production of anti-CgA mAb for immunohistochemistry diagnosis in this study, and the current study also provides conclusive guidelines for preparation of mAbs and implements in immunohistochemistry diagnosis.