| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Digestive Diseases Branch (M.J.B., R.T.J.), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), and Biostatistics and Data Management Section (D.L., D.J.V.), National Cancer Institute, National Institutes of Health (NIH), Bethesda, Maryland 20892; Division of Digestive and Liver Diseases (B.A., M.M., V.C., G.D.F.), University "La Sapienza," 00189 Rome, Italy; Department of Pathology and Laboratory Medicine (T.V.L., C.B.), Section of Anatomic Pathology, University of Parma, 43100 Parma, Italy; Department for Internal Medicine I (M.J.B., A.P.), University Hospital Hamburg-Eppendorf, 20245 Hamburg, Germany; and Department of Medicine and Bio-Regulatory Science (T.I.), Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan
Address all correspondence and requests for reprints to: Dr. Robert T. Jensen, Building 10, Room 9C-103, 10 Center Drive, Bethesda, Maryland 20892-1804. E-mail: RobertJ{at}bdg10.niddk.nih.gov.
| Abstract |
|---|
|
|
|---|
Objectives: Our objective was to prospectively analyze ECL-cell changes and gastric carcinoids (ECL-cell tumors) in a large series of MEN1/ZES patients to detect risk factors and deduct clinical guidelines.
Setting and Patients: Fifty-seven consecutive MEN1/ZES patients participated in this prospective study at two tertiary-care research centers.
Interventions and Outcome Measures: Assessment of MEN1, gastric hypersecretion, and gastroscopy with multiple biopsies was done according to a fixed protocol and tumor status. ECL-cell changes and
-human chorionic gonadotropin staining were assessed in each biopsy and correlated with clinical, laboratory, and MEN1 features.
Results: ECL-cell proliferative changes were universally present, advanced changes in 53% and carcinoids in 23%. Gastric nodules are common and are frequently associated with carcinoids. Patients with high fasting serum gastrin levels, long disease duration, or a strong
-human chorionic gonadotropin staining in a biopsy are at higher risk for an advanced ECL-cell lesion and/or gastric carcinoid.
Conclusions: Gastric carcinoids and/or advanced ECL-cell changes are frequent in MEN1/ZES patients, and therefore, regular surveillance gastroscopy with multiple routine biopsies and biopsies of all mucosal lesions are essential. Clinical/laboratory data and biopsy results can be used to identify a subgroup of MEN1/ZES patients with a significantly increased risk for developing gastric carcinoids, allowing development of better surveillance strategies.
| Introduction |
|---|
|
|
|---|
Although there are a number of recent studies of PETs and foregut carcinoids in MEN1 (5, 7, 8), little is known about gastric carcinoids [also called gastric neuroendocrine tumors or enterochromaffin-like (ECL)-cell tumors]. Although it is established that gastric carcinoids occur almost exclusively in patients with MEN1 with Zollinger-Ellison syndrome (ZES; 21–70% of MEN1 patients; type 2 carcinoids) (4, 9, 10) and that they can be malignant in 10–30% of cases (11, 12, 13), their frequency, contributing factors, or association with other features of MEN1 are largely unknown. This has occurred because previous studies are limited by small patient numbers, their retrospective nature, and the small number of gastric biopsies analyzed. Furthermore, it is proposed that gastric carcinoids develop in chronic hypergastrinemic states, such as MEN1/ZES, atrophic gastritis, and pernicious anemia, due to proliferative effects of gastrin on gastric ECL cells, resulting in hyperplasia, dysplasia, and finally, carcinoids (10, 14, 15). Therefore, they are more accurately called ECL-cell tumors than gastric carcinoids or gastric neuroendocrine tumor, because the latter terms could also include tumors arising from gastrin- or serotonin-producing cells. Although ECL-cell hyperplastic changes are reported in MEN1/ZES patients (16, 17, 18, 19, 20), there have been no large systematic studies correlating these changes with the development of ECL-cell tumors in these patients.
Therefore, the purpose of this prospective study was to assess the frequency and extent of ECL changes and ECL-cell tumors in a large number of MEN1/ZES patients and to identify for the first time possible predictive factors for each of these. This was accomplished by studying a large number of consecutive MEN1/ZES patients using an established protocol involving a large number of systematic gastric biopsies (10).
| Patients and Methods |
|---|
|
|
|---|
All patients admitted to the National Institutes of Health (NIH) with a confirmed diagnosis of MEN1/ZES from 1996–2005 or to La Sapienza University Hospital from 1988–1999 were included. This study was approved at the NIH by the Clinical Research Committee of the National Institute of Diabetes and Digestive and Kidney Diseases or by the local (La Sapienza) ethical committee in adherence with the declaration of Helsinki (10).
Methods
Diagnostic criteria for MEN1 syndrome and ZES were as described previously (4, 6, 21), and the onset of MEN1 and ZES was determined (4, 6, 21, 22). To establish the diagnosis of ZES, patients underwent a gastric acid analysis [basal/maximal acid output (BAO/MAO)] (23), fasting serum gastrin (FSG) measurements (10, 24), and a secretin test. To define the extent/localization of PETs and other MEN1 tumors, imaging studies were performed (5, 8, 25, 26).
Specific protocol
At the time of gastric biopsy, all patients underwent evaluation of MEN1 status, ZES diagnosis, and determination of tumor location/extent. During the initial evaluation as well as during subsequent yearly assessments, MEN1 status and ZES tumor features were assessed (21). On each follow-up, acid studies were performed to allow assessment of acid secretory control (27, 28). NIH patients were classified as having sustained hypochlorhydria if acid output was less than 0.2 mEq/h for at least 50% of all yearly assessments (10, 27, 29).
Gastroscopic biopsy and processing
Biopsies were performed using an Olympus GIF 2T100 gastroscope (Olympus America Corp., Melville, NY), and 10 Jumbo gastric biopsies (eight body and two antrum; NIH), or eight biopsies (six body and two antrum; La Sapienza) were taken (10, 30). The corporeal routine biopsies were taken in a preset order: at the NIH, four from the greater curvature (three, La Sapienza) and four from the lesser curvature (three, La Sapienza) (10, 30). All gastric nodules were biopsied. Biopsies were processed as described previously (10, 30).
Histology and immunohistochemistry
Serial 5-µm-thick sections perpendicular to the mucosal surface were stained with hematoxylin-eosin for evaluation of the type of mucosa, Giemsa stain for Helicobacter pylori evaluation, and immunostaining for endocrine cells (10).
-Human chorionic gonadotropin (
-hCG) immunoreactivity (IR) was determined as described previously (10) and graded from 0–3+ depending on the number of positive cells per linear millimeter as described previously (10).
Endocrine cell evaluation
The distribution of ECL-cell changes was investigated in sections immunostained for chromogranin A, with exclusion of areas of intestinal metaplasia. Biopsies were classified as evaluable or nonevaluable (10, 30). Carcinoids were diagnosed when lesions exceeded 0.5 mm (10, 14). ECL-cell changes were qualitatively evaluated by two independent examiners as proposed by Solcia et al. (14). Biopsies were graded on the severity of each hyperplastic lesion. Results were classified two different ways, either according to the highest grade of ECL-cell hyperplasia (10, 30) or by compiling a patient ECL-cell index as described previously (10, 30). Briefly, this involves assigning a numerical value to each biopsy that increases with increasing grades and severity of hyperplasia (diffuse, linear, micronodular, and adenomatoid) or dysplasia and then averaged for the number of biopsies as described previously (10, 30), with the modification that each individual carcinoid was assigned a score of 14. Gastritis was assessed according to the updated Sydney System, and the expression of
-hCG was evaluated (10).
Statistics
Fishers exact test, the Mann-Whitney U test, and the Cochran-Armitage test were used. Linear regression was used to find the best fit in simple regression analyses and the Spearman rank-correlation method to determine the correlation coefficients and exact P values. To find the factors that remain significant after adjustment for each other, the ECL-cell index was log-transformed, and linear regression with forward and backward selection was used. The detection of carcinoids was similarly analyzed with the logistic regression model and the
-hCG-IR with extended logistic regression of ordered categories of less than or equal to 1+, 2+, and 3+. A two-tailed P value of <0.05 was considered significant.
| Results |
|---|
|
|
|---|
|
|
|
|
-hCG-IR was pronounced in the whole spectrum of ECL-cell changes, whereas it tended to be sparse or absent in dysplasia and carcinoids (Fig. 2
The ECL-cell index varied from 0.13–14 (mean 3.44). The ECL-cell index was less than 3 in 61%, 3–9 in 30%, and more than 9 in 9% of patients. The ECL-cell index correlated well with the most advanced ECL-cell change per patient (r = 0.94; P < 0.0001) (Fig. 3
).
The mean
-hCG score for all patients was 2.36 ± 0.12 (Fig. 1
, middle panel). Seventeen percent of routine biopsies were graded 0, 29% 1+, 22% 2+, and 31% 3+ (Fig. 1
, middle panel). The majority of patients (34 patients) showed strong
-hCG-IR (3+) in at least one biopsy (Fig. 3
, right panel). The
-hCG-IR correlated significantly with the most advanced ECL-cell change (r = 0.55; P < 0.0001) and the ECL-cell index (r = 0.52; P < 0.0001) (Fig. 3
).
Patients with a higher ECL-cell index had a longer ZES disease duration, had a higher ECL-cell index (Tables 2
and 3
and Fig. 4B
1), longer duration of medical ZES therapy (Tables 2
and 3
and Fig. 4D
1), a longer duration of omeprazole treatment (Tables 2
and 3
and Fig. 4C
1), and a higher FSG (Tables 2
and 3
and Fig. 4
). There was a very strong correlation (r = 0.58; P < 0.0001) between the ECL-cell index and the FSG level (Fig. 4A
1). Patients with a duodenal primary had a higher ECL-cell index (Tables 2
and 3
), and those with localized disease had a lower ECL-cell index. Multivariate analysis showed serum gastrin level (67% increase in ECL-cell index for each factor 10 increase in gastrin, P < 0.0001), the presence of a proven duodenal primary (70% increase, P = 0.0060), and the duration of ZES (27% increase for every 10 yr, P = 0.023) are independently associated with a higher ECL-cell index (Table 2
).
|
|
|
-hCG-IR and the presence of a duodenal primary (Tables 2
-hCG-IR and the duration of ZES (Fig. 4B
-hCG-IR.
In general, clinical, laboratory, or tumor variables factors associated with a high ECL-cell index and a high
-hCG-IR are also associated with carcinoids (Tables 2
and 3
). Especially important was the association of carcinoids with high FSG values (P = 0.0004), long ZES duration (P = 0.0036), or various clinical/tumor factors (duodenal primary, localized disease, and duration of medical treatment) (Tables 2
and 3
). Numerous other variables listed in the footnote of Table 3
did not influence the ECL-cell index, the
-hCG-IR, or the incidence of carcinoids. Multivariate analysis demonstrated only the FSG (odds ratio = 20; P = 0.0011) and the presence of localized disease (odds ratio = 0.051; P = 0.018) are independently associated with the presence of carcinoids.
To analyze whether patients with carcinoids have more advanced ECL-cell changes in the biopsies not derived from carcinoids, we calculated a modified ECL-cell index that did not assign any score to carcinoids. Patients with carcinoids had a significantly higher modified ECL-cell index than patients without carcinoids (4.94 ± 0.41 vs. 2.01 ± 0.16, P < 0.0001; data not shown).
A number of histological (any biopsy with at least LH severe), endoscopic (nodules present), clinical (MAO > 70 mEq/h), and laboratory (FSG > 1400 pg/ml) findings showed a relatively high sensitivity (80–100%) and specificity (70–100%) (Table 3
) for the presence of carcinoids and therefore could be clinically helpful in identifying a subset of MEN1/ZES patients at high risk of having a carcinoid.
| Discussion |
|---|
|
|
|---|
The present prospective study has none of these limitations. A large number of biopsies (i.e. six to eight) were systematically taken from the greater/lesser curvature, any mucosal abnormality biopsied, and
-hCG expression systematically assessed in a large number of patients. Furthermore, assessments were performed in MEN1/ZES patients that were part of a prospective study (4, 21), so findings could be related to other features of MEN1 and ZES.
Our results demonstrate ECL-cell changes are universal in MEN1/ZES patients with no patient having a normal ECL-cell pattern in all biopsies. This result differs from a number of small series (all fewer than 10 patients) that report 14–65% of MEN1/ZES patients have normal ECL-cell patterns (17, 18). However, it is in agreement with other series (16, 19, 20, 38) reporting ECL-cell hyperplasia in 92–100%. These results are also similar to findings in sporadic ZES in which 80–100% show some ECL-cell change (10, 16, 17, 35). In the majority of MEN1/ZES patients, the ECL-cell changes are advanced with 53% having advanced hyperplasia (at least LH mild). This percentage is higher than in most small series of MEN1/ZES patients where 25–47% (mean 35 ± 4%, six series) had this extent of changes (16, 17, 18, 19, 20). It is also a higher percentage than occurs in sporadic ZES, where 7–53% have an ECL change of at least LH (18, 19, 20). Furthermore, 23% of our patients had ECL-cell tumors, which is higher than the 0–14% (mean 2 ± 1.5%, nine series) reported by most, but not all (25–33% incidence) (37), small series of MEN1/ZES patients (4, 17, 18, 19, 20, 36). This percentage is higher than reported in patients with sporadic ZES, where no ECL-cell tumors are reported in most series (16, 18, 19, 20), even though at least one study (10) used a large number of biopsies similar to the present study. Data from this study combined with studies from the literature support the conclusion that ECL-cell tumors are more than 70 times more common in MEN1/ZES than in sporadic ZES patients. Because duration of hypergastrinemia and FSG levels in our MEN1/ZES patients are comparable to those of 106 sporadic ZES patients investigated using a similar protocol (10), the predilection of MEN1/ZES patients for developing carcinoids cannot be explained by more severe hypergastrinemia or more prolonged exposure to the trophic effect of gastrin in our patients. These results support the proposal that the genetic changes in MEN1 patients render ECL cells more sensitive to the proliferative effect of gastrin (39).
The degree of hypergastrinemia correlates with the extent of ECL-cell changes in animal studies and in patients with atrophic gastritis (10, 20, 40). In ZES patients (primarily sporadic), the results are contradictory. Some studies report a positive correlation between these two variables (10, 17, 20, 35); however, no correlation was found in others (36, 41). Furthermore, there are no studies demonstrating that the level of hypergastrinemia correlates with the occurrence of ECL-cell tumors in ZES patients, as it does in atrophic gastritis (40). A number of results in our study support the conclusion that the magnitude of hypergastrinemia is directly correlated to the level of ECL-cell changes and the presence of carcinoids in MEN1/ZES patients. First, there was a highly significant positive correlation between the ECL-cell index and FSG level (Fig. 4A
1). Second, the MAO, which has been shown to reflect the parietal cell mass, which is affected directly by the magnitude of hypergastrinemia in ZES patients (24, 42), was correlated to the ECL-cell index in the present study (Fig. 4E
1). Third, patients with low FSG values (<490 pg/ml) or with localized disease, which have been previously reported to have lower FSG levels (24), had a lower ECL-cell index (Tables 2
and 3
).
Age or gender have been reported to influence ECL-cell changes and/or the development of ECL-cell tumors in animal and in some (16, 40), but not all (10, 35) human studies. We did not find such a correlation. These results are similar to findings in a recent study of sporadic ZES patients (10). Our results support the proposal that gender or age might be affecting the extent of hypergastrinemia in these different non-ZES groups of patients, which then affects the severity of ECL-cell changes. In contrast, in the current study, there was no significant difference in FSG levels in male and female or in old and young ZES patients (data not shown).
Although there are no data specifically on MEN1/ZES patients, the duration of hypergastrinemia and treatment with PPIs have been associated with increased ECL-cell changes in some (17, 38), but not all (10, 18, 35, 36, 37, 41), studies of ZES patients. In the present study, ZES duration was independently associated with the severity of ECL-cell changes and the presence of carcinoids (Fig. 4B
1 and Tables 2
and 3
). This result differs from findings in sporadic ZES patients (10). The reason for this difference is currently unclear, although it could be related to the earlier onset of ZES in MEN1 patients (4). Also, hypercalcemia from the hyperparathyroidism can increase serum gastrin levels in MEN1/ZES patients (4, 34, 43), and at the time of the biopsies in the present study, more than half of the MEN1 patients had a prior parathyroidectomy, so the serum gastrin levels were very likely higher in the past. Previous studies demonstrated ectopic expression/overexpression of
-hCG by neuroendocrine tumors (42). In the stomach,
-hCG was associated with hypergastrinemic states, which in some cases correlated with the presence of malignancy (10, 44). We found proliferative ECL cells ectopically express
-hCG in most MEN1/ZES patients, and overexpression correlates with the severity of ECL-cell changes, similar to results in sporadic ZES (10). Both high FSG and long duration of omeprazole treatment independently correlated with high
-hCG-IR. Strong
-hCG-IR was present in virtually all patients with carcinoids, even those with a low ECL-cell index (Fig. 3
), supporting the proposal that high
-hCG-IR may be an independent predictor for carcinoids in ZES (10). Whereas in the pancreas in some studies (45),
-hCG-IR is associated with tumor malignancy, in the stomach in our study and others, it is largely restricted to preneoplastic changes (15).
Our study identified important findings/risk factors for the presence of advanced ECL-cell changes and/or ECL-cell tumors, from which can be proposed guidelines summarized in Table 4
. Particularly important findings were that 53% of MEN1/ZES patients have advanced ECL-cell changes and 23% ECL-cell tumors and the demonstration of the necessity to biopsy all gastric nodules. Our study shows that gastric nodules are more frequent than previously reported (36), occurring in 44% of patients, and they frequently harbor carcinoids. The use of the risk factors summarized in Tables 2
and 3
should allow identification of a subgroup of MEN1/ZES patients at greater risk for developing ECL-cell tumors and allow stratification for follow-up. Long-term follow-up studies of these patients will be particularly important to attempt to identify risk factors for malignancy, the best methods to assess growth, and the best treatment methods for patients with multiple ECL-cell tumors.
|
| Footnotes |
|---|
Disclosure Summary: All authors have nothing to disclose.
First Published Online February 12, 2008
Abbreviations: BAO, Basal acid output; DH, diffuse hyperplasia; ECL, enterochromaffin-like; FSG, fasting serum gastrin;
-hCG,
-human chorionic gonadotropin; IR, immunoreactivity; LH, linear hyperplasia; MAO, maximal acid output; MEN1, multiple endocrine neoplasia type 1; MH, micronodular hyperplasia; PET, pancreatic endocrine tumor; PPI, proton pump inhibitor; ZES, Zollinger-Ellison syndrome.
Received October 11, 2007.
Accepted January 31, 2008.
| References |
|---|
|
|
|---|
-subunit by endocrine cells of the oxyntic mucosa is associated with hypergastrinemia. Hum Pathol 19:580–585[CrossRef][Medline]
-chain production by pancreatic endocrine tumors: a specific marker for malignancy. Immunocytochemical analysis of 155 patients. Cancer 51:277–282[CrossRef][Medline]This article has been cited by other articles:
![]() |
C. S. Landry, G. Brock, C. R. Scoggins, K. M. McMasters, and R. C. G. Martin II A Proposed Staging System for Gastric Carcinoid Tumors Based on an Analysis of 1,543 Patients Ann. Surg. Oncol., January 1, 2009; 16(1): 51 - 60. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |