Evaluation of Chromogranin a Expression in Serum and Tissues of Breast Cancer Patients

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.

[Neuroendocrine tumors of the breast: Myth or reality? A systematic review]

Primary neuroendocrine breast carcinomas are rare and little-known tumors. Only a limited number of studies on neuroendocrine breast carcinomas have been reported in the literature, and the vast majority of them are small retrospective series or case reports. According to the World Health Organization (WHO), they account for only 2 % to 5 % of breast cancers. Their diagnosis relies on the presence of a neuroendocrine architecture and the expression of neuroendocrine markers (chromogranin A and/or synaptophysin). The revised 2012 WHO classification subdivides them into three categories: (i) well-differentiated neuroendocrine carcinomas, (ii) poorly differentiated neuroendocrine carcinomas or small-cell carcinomas, and (iii) invasive breast carcinomas with neuroendocrine differentiation. Their clinical features and radiological characteristics are not different from those of other types of breast cancer. Because of discordant results, their clinical outcome is still poorly defined. So far, no standard treatment has been established, and most clinicians draw on their experience of invasive ductal cancer. The role of specific treatments like platinum-based chemotherapy, somatostatin analogues, peptide receptor radionucleide therapy or temozolomide remains unclear. A better knowledge of the molecular pathways involved in their carcinogenesis could help to identify new potential therapeutic targets. The efficacy of targeted therapies has to be studied.

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.

Chromogranin A in gastrinomas: Promises and pitfalls

Patients with neuroendocrine tumors are found with increasing frequency. Accordingly, knowledge about relevant tumor markers and assays for diagnosis and control has become essential. Neuroendocrine tumors release one or more granin proteins. Of these, chromogranin A (CgA) has so far become the most widely used general marker. The CgA protein is, however, extensively cleaved and otherwise modified during the biosynthetic processing. In addition, the CgA-processing in individual tumors varies considerably. But only few CgA-assays have taken the processing into account and characterized the assays with respect to precise epitope-specificity. Consequently, we do not know which fragments most CgA-assays measure. It is therefore at present difficult to compare CgA-measurements from tumor patients. Some tumors, however, release - in addition to granins - also a specific hormone that causes a clinical syndrome. This review uses gastrinomas (gastrin-producing tumors) as a starting point for discussion of CgA versus peptide hormone as tumor marker. Data available so far indicate that well-defined assays for gastrin have significantly higher diagnostic sensitivity than CgA measurements in gastrinomas. But the review suggests that CgA-quantitation using processing-independent analysis (PIA) may provide an equally high diagnostic sensitivity and in addition offer a simple possibility for estimation of the tumor-burden.

Chromogranin A is a reliable serum diagnostic biomarker for pancreatic neuroendocrine tumors but not for insulinomas

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) are a group of rare tumors. Chromogranin A (CgA) was considered as the most practical and useful serum tumor marker in PNET patients. But peripheral blood levels of CgA are not routinely tested in Chinese patients with PNETs. This study was to assess the diagnostic value of CgA in Chinese patients with PNETs especially in patients with insulinomas.

METHODS

Eighty-nine patients with PNETs including 57 insulinomas and 32 non-insulinoma PNETs as well as 86 healthy participants were enrolled in this study between September 2003 and June 2013. Serum levels of CgA were measured by ELISA method. Expression of CgA protein was detected in 26 PNET tissues including 14 insulinomas by immunohistochemical staining.

RESULTS

Serum levels of CgA in 89 PNET patients were significantly higher than that in healthy controls (P = 7.2 × 10-9). Serum levels of CgA in 57 patients with insulinomas (median 64.8 ng/ml, range 25-164) were slightly higher than the levels in healthy controls (median 53.4 ng/ml, range 39-94) but much lower than the levels in 32 patients with non-insulinoma PNETs (median 193 ng/ml, range 27-9021), P = 0.001. The serum CgA levels were reduced in 16 of 17 patients with insulinomas after tumor resection. ROC curve showed that CgA values at 60 ng/ml distinguished patients with insulinomas from healthy controls but its sensitivity and specificity were 66.7% and 73.3%, respectively. In contrast, CgA values at 74 ng/ml distinguished patients with non-insulinoma PNETs from healthy controls, and the sensitivity and specificity were 65.6% and 91.9%, respectively. Except for two insulinomas with negative staining of CgA, 12 insulinoma tissues showed positive staining of CgA.

CONCLUSION

CgA is a reliable serum diagnostic biomarker for PNETs but not for insulinomas.

The biochemical utility of chromogranin A, chromogranin B and cocaine- and amphetamine-regulated transcript for neuroendocrine neoplasia

Neuroendocrine neoplasia (NEN) is a heterogeneous group of tumours and often represents a therapeutic challenge to clinicians. The peptides chromogranin A (CgA), chromogranin B (CgB) and cocaine- and amphetamine-regulated transcript (CART) are widely distributed throughout the neuroendocrine system. CgA and CgB have been used as general NEN biomarkers for many years, while CART has only recently been identified. Of these biomarkers, CgA is the most commonly used. However, circulating CgA concentrations exhibit considerable intra-individual biological variation, are altered by proton pump inhibitors (PPIs) and somatostatin analogues and are elevated in non-NEN malignancies. Therefore, interpretation of CgA results must be in the context of these confounding factors. The effects of treatment and non-NEN conditions on circulating CgB and CART concentrations are less well understood. CgB is less affected by impaired renal function and PPIs than CgA; while, circulating CART concentrations lack a diurnal variation in humans and are more reliable markers of pancreatic NEN malignancy than CgA. The utility of circulating CgA measurements in NEN prognosis, surveillance and disease recurrence has been widely investigated. However, the utility of CgB and CART in NEN management is yet to be elucidated. Further studies are needed to establish whether CgB and CART are useful alternatives to CgA.

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.

The clinical relevance of chromogranin A as a biomarker for gastroenteropancreatic neuroendocrine tumors

Chromogranin A, although it exhibits limitations, is currently the most useful general tumor biomarker available for use in the diagnosis and management of gastroenteropancreatic neuroendocrine tumors (NETs). The value of the chromogranin A lies in its universal cosecretion by the majority of neuroendocrine cells that persists after malignant transformation. Clinicians aware of the physiologic role of chromogranin A and its secretion in a variety of non-NET-related pathologic conditions can use this protein as a moderately effective tumor biomarker in the management of GEP-NETs.

[Carcinoid tumors]

The authors review the most important clinical aspects of carcinoid tumors. Carcinoid tumors originating in neuroendocrine cells are rare, usually slowly-growing neoplasms, however, they may present as aggressive and rapidly progressing tumors. Epidemiologic data indicates that their prevalence is gradually increasing, which may be explained, at least in part, by the development and wider use of advanced diagnostic methods. A considerable proportion of patients with neuroendocrine tumors are symptom-free, whereas others may have carcinoid syndrome or symptoms of other endocrine syndromes. Early diagnosis may be established by the measurement of biochemical markers (serum chromogranin A, urinary 5-hydroxyindoleacetic acid) and advanced localization methods. A considerable number of patients are diagnosed at the late stages of the disease; in these cases surgical cure is not possible but surgical and/or interventional radiologic procedures which reduce tumoral mass should be still considered. The most effective drugs for symptomatic treatment of carcinoid tumors are somatostatin analogues; in addition to their beneficial effect on clinical symptoms they may stabilize tumor growth for many years and, less frequently, may produce tumor regression. The use of chemotherapeutic agents is considered in patients with aggressive, rapidly growing and advanced tumors; initial findings with temozolomide and thalidomide in clinical trials raise the possibility that these chemotherapeutic agents may prove to be new therapeutic options. Radioisotope-labeled peptide receptor therapy with 131 I-MIBG, 90 Y-DOTA-TOC or 177 Lu-DOTA-TOC may offer a highly effective option for patients with progressive and advanced stage of neuroendocrine tumors. Initial observations obtained in clinical trials with some tyrosine kinase inhibitors, antibodies against tyrosine kinases, and with inhibitors of mammalian target of rapamycin (mTOR) support the possibility that at least some of these new agents may have a role in future treatment options in patients with advanced neuroendocrine tumors.

Neuroendocrine differentiation in breast cancer: established facts and unresolved problems

Neuroendocrine breast carcinoma (NEBC) diagnosis relies on (i) presence of morphologic neuroendocrine features, and (ii) neuroendocrine markers expressed in more than 50% of tumor cells. The World Health Organization classification describes 3 main histologic types: the solid, the small/oat cell, and the large cell variant. In addition, we have recently proposed a further categorization into 5 subgroups: the first 3 categories encompass solid lesions and include (i) solid cohesive carcinomas, (ii) alveolar carcinomas, and (iii) small cell carcinoma; the last subgroups include mucin-producing tumors which are (iv) solid papillary carcinomas and (v) cellular mucinous carcinomas. Chromogranin A and synaptophysin have been considered as the most sensitive and specific neuroendocrine markers in NEBC. At the molecular level, recent gene expression profiling studies have shown that NEBCs pertain to the luminal molecular type, being positive for hormone receptors and negative for HER2. Moreover, it has been demonstrated that mucinous and neuroendocrine carcinomas are transcriptionally distinct from conventional invasive ductal carcinomas. Following the above criteria, NEBCs constitute approximately 1% of all breast carcinomas. The clinical effect of neuroendocrine breast cancer is still a matter of debate; however, when compared with unselected breast cancers, NEBCs show a less aggressive clinical behavior.

Chromogranin A--biological function and clinical utility in neuro endocrine tumor disease

BACKGROUND

Neuroendocrine tumors (NETs) are a form of cancer that differ from other neoplasia in that they synthesize, store, and secrete peptides, e.g., chromogranin A (CgA) and amines. A critical issue is late diagnosis due to failure to identify symptoms or to establish the biochemical diagnosis. We review here the utility of CgA measurement in NETs and describe its biological role and the clinical value of its measurement.

METHODS

Literature review and analysis of the utility of plasma/serum CgA measurements in NETs and other diseases.

RESULTS

CgA is a member of the chromogranin family; its transcription and peptide processing are well characterized, but its precise function remains unknown. Levels are detectable in the circulation but vary substantially (approximately 25%) depending on which assay is used. Serum and plasma measurements are concordant. CgA is elevated in approximately 90% of gut NETs and correlates with tumor burden and recurrence. Highest values are noted in ileal NETs and gastrointestinal NETs associated with multiple endocrine neoplasia type 1. Both functioning and nonfunctioning pancreatic NETs have elevated values. CgA is more frequently elevated in well-differentiated tumors compared to poorly differentiated NETs. Effective treatment is often associated with decrease in CgA levels. Proton pump inhibitors falsely increase CgA, but levels normalize with therapy cessation.

CONCLUSIONS

CgA is currently the best available biomarker for the diagnosis of NETs. It is critical to establish diagnosis and has some utility in predicting disease recurrence, outcome, and efficacy of therapy. Measurement of plasma CgA is mandatory for the effective diagnosis and management of NET disease.

How the hindgut can cure type 2 diabetes. Ileal transposition improves glucose metabolism and beta-cell function in Goto-kakizaki rats through an enhanced Proglucagon gene expression and L-cell number

BACKGROUND

It has been hypothesized that glucagon-like peptide-1 (GLP-1), secreted by ileal L cells, plays a key-role in the resolution of type 2 diabetes after bariatric operations whose common feature is an expedite nutrient delivery to the hindgut. Ileal transposition (IT), an operation that permits L-cell stimulation by undigested food, was employed to verify this theory.

METHODS

IT was carried out in Goto-Kakizaki (GK) type 2 diabetic rats and in euglycemic Sprague-Dawley (SD) rats. Glucose tolerance, insulin resistance, food-intake, body weight, pancreas morphology, and function were evaluated to track the effects of IT on diabetes. Intact GLP-1 secretion and gene expression pattern of the transposed ileum were investigated to verify the molecular bases of the hindgut action.

RESULTS

In GK rats, IT significantly improved glucose tolerance, insulin sensitivity, and acute insulin response without affecting body weight and food intake. Immunohistochemistry revealed remodeled islets strictly resembling that of euglycemic rats and signs of beta-cell neogenesis starting with exocrine structures. GLP-1 secretion in GK transposed rats was characterized by a more sustained response to oral glucose compared with nontreated rats. Gene expression of Proglucagon, Proconvertase 1/3 (PC1/3), and Chromogranin A in the transposed ileum significantly enhanced. Effects on glucose metabolism and pancreas morphology were not observed in the euglycemic rats as a consequence of the glucose-dependent action of GLP-1.

CONCLUSIONS

This study gives strong evidences for the crucial role of the hindgut in the resolution of diabetes after Roux-en-Y gastric bypass (GBP) and biliopancreatic diversion (BPD). Moreover, these findings confirm at the preclinical level that IT is a surgical procedure of possible relevance in the therapy of type 2 diabetes in non-overweight and mildly obese patients.

Evaluation of Chromogranin A Expression in Patients with Non-Neuroendocrine Tumours

BACKGROUND

Chromogranin A (CgA) is well established as a serum marker for neuroendocrine tumours and has also been associated with some non-neuroendocrine tumours, suggesting a possible role for somatostatin analogues such as octreotide in the treatment of these tumours.

OBJECTIVE

The aim of this study was to measure plasma CgA levels in patients with various non-neuroendocrine tumours in order to identify those patients who might benefit from octreotide therapy.

METHODS

Plasma CgA levels were tested in 151 patients with metastatic non-neuroendocrine tumours. Patients with highly elevated levels were assessed by OctreoScan scintigraphy to determine their somatostatin receptor status, and those with positive results were offered treatment with the somatostatin analogue octreotide, 20 mg every 4 weeks, and followed up every 3 months.

RESULTS

CgA levels were elevated (>18 U/L) in 34/72 patients with breast cancer, 11/21 with lung cancer, 10/28 with gastrointestinal cancer, 7/12 with gynaecological cancer, 6/9 with genitourinary cancer, 5/5 with haematological cancer, and 3/4 with head and neck cancer. Eight patients with CgA levels >150 U/L underwent scintigraphy, five of whom (two colorectal, two prostate, one non-small cell lung cancer [NSCLC]) showed positive results and received treatment with octreotide. Follow-up for a mean 12-16 months showed improvements in biochemical parameters, cenesthesis and quality of life.

CONCLUSION

CgA levels were found to be elevated in approximately 50% of patients with non-neuroendocrine tumours. Further studies are required to determine the value of CgA as a marker for non-neuroendocrine tumours and the role of somatostatin analogues as a treatment for these tumour types.

Serum chromogranin-A in hepatocellular carcinoma: Diagnostic utility and limits

AIM: The utility of serum alpha-fetoprotein (α-FP) for the detection of hepatocellular carcinoma (HCC) is questionable. High serum levels of chromogranin-A (CgA) have recently been reported in HCC. Impaired hepatic, renal, and heart functions influence circulating CgA. The aim of this study was to assess sensitivity and specificity of serum CgA as a marker of HCC in patients with liver cirrhosis (LC).

METHODS: Serum CgA levels were measured by RIA in 339 patients of which 54 HCC, 132 LC, 45 chronic hepatitis (CH), 27 chronic heart failure (CHF), 36 chronic renal failure (CRF), 45 chronic inflammatory bowel disease (IBD) as disease controls and in 75 healthy controls. Patients with liver disease or IBD and concomitant renal and/or heart failure were excluded. Pearson correlation, non-parametric combination test and confidence interval analysis were used for statistical analysis.

RESULTS: Serum CgA above normal values (100 ng/mL) were found in 83% of HCC patients, in 48% of LC patients, in 20% of CH patients, in 33% of IBD patients, in 92% of CRF patients, in 100% of CHF patients, and in none of the healthy controls. The mean CgA values in HCC (769±1 046), in LC (249±369), in CH (87±94), in CRF (1390±1401), in CHF (577±539), in IBD (146±287) were significantly higher than those in healthy controls (48±18). HCC patients had higher CgA values (P<0.01) than LC, CH, and IBD patients but did not differ from those with CRF or CHF. The 95% CI for the mean (250-1289 ng/mL) in HCC patients was selected as a CgA range and the lower value of such range was assumed as cut-off. Sensitivity and specificity of CgA, calculated in relation to the cut-off in patients with cirrhosis and HCC, were respectively 61% (CI 48-73%) and 82% (CI 75-88%). Serum α-FP values were >200 ng/mL in 21% of the HCC patients and in none of the LC patients. No significant correlation was found between α-FP and CgA in patients with HCC and in patients with cirrhosis.

CONCLUSION: When HCC is suspected and α-FP is normal or <200 ng/mL, CgA serum values represent a complementary diagnostic tool, unless kidney or heart failure is present.

Neuroendocrine markers in adenocarcinomas: an investigation of 356 cases

AIM: To investigate the incidence of neuroendocrine (NE) cells and their hormone products in adenocarcinomas and evaluate their significance in clinical pathology and prognosis.

METHODS: By using tissue sectioning and immunocyto-chemistry, 356 cases of adenocarcinomas were studied to examine the presence of chromorgranin and polypeptide hormones in adenocarcinoma samples from our hospital.

RESULTS: The positive rate of NE cells and hormone products was 41.5% (54/130) and 59.3% (32/54), respectively in large intestinal adenocarcinoma cases; 39.6% (38/96) and 36.8% (14/38), respectively in gastric cancer cases; 38.1% (8/21) and 50.0% (4/8), respectively in prostatic cancer cases; 21.0% (17/81) and 17.6% (3/17), respectively in breasr cancer cases; 17.9% (5/28) and 60.0% (3/5), respectively in pancreatic cancer cases. Among carcinomas of large intestine, pancreas and breast, the highly differentiated NE cell numbers were higher than the poorly differentiated NE cell numbers; while the gastric carcinoma cases had more poorly differentiated NE cells than highly differentiated NE cells. The higher detection rate of NE cells and their hormone products, the higher 5-year survival rate among the large intestine cancer cases.

CONCLUSION: Close correlation was observed between NE cells and their hormone products with the cancer differentiations. For colorectal carcinomas, there is a close correlation of the presence of NE cells and their hormone products with the tumor staging and prognosis.