Oesophageal cancers rank as the eighth most common cancer and the sixth most common cause of cancer death, worldwide. Gastric atrophy, as determined by a low serum pepsinogen I/II ratio, may be associated with an increased risk of oesophageal squamous cell carcinoma (OSCC). Ghrelin, a hormone which, like pepsinogen, is produced in the fundic glands of the stomach, may be a sensitive and specific marker of gastric atrophy, but its association with OSCC is not known.
To examine the relationship between baseline serum ghrelin concentration and subsequent risk of OSCC, we conducted a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. 82 cases of OSCC were matched (1:1) by age and date of blood draw to controls from the ATBC study. Serum ghrelin was measured by radioimmunoassay. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using conditional logistic regression with adjustment for potential confounders.
For those individuals in the lowest quartile of serum ghrelin, compared to those in the highest, the multivariate odds ratio of subsequent OSCC was 6.83 (95% CI: 1.46, 31.84). These associations were dose dependent (P for trend = 0.005 for both), and independent of the effects of low pepsinogen I/II ratio (a marker of gastric fundic atrophy) and Helicobacter pylori infection. The significance of these associations remained even for individuals developing OSCC up to 10 years after baseline ghrelin measurement, though they become attenuated after 10 years.
Lower baseline concentrations of serum ghrelin were associated with an increase in risk of OSCC. Further studies are needed to confirm this finding in other populations and to explore the role of ghrelin in the aetiology of OSCC.
ghrelin; oesophageal squamous cell carcinoma; atrophy
Iodine concentrates in gastric tissue and may act as an antioxidant for the stomach. We previously showed that self-reported goiter was associated with significantly increased risk of gastric noncardia adenocarcinoma (GNCA) and non-significantly increased risks of gastric cardia adenocarcinoma (GCA) and esophageal squamous cell carcinoma (ESCC) in a prospective case-cohort study in a high-risk population in China. Negatively correlated with iodine levels, serum thyroglobulin (Tg) is a more sensitive biomarker of iodine deficiency than goiter. This study aimed to determine whether baseline serum Tg was also associated with development of GNCA, GCA, and ESCC in the same cohort, the Linxian General Population Nutrition Intervention Trial. Sera from approximately 200 subjects of each case type and 400 non-cases were tested for serum Tg concentration using appropriate assays. Tg was modeled as sex- and assay-specific quartiles in Cox regression models adjusted for age, smoking, alcohol, Helicobacter pylori status, pepsinogens I/II ratio, family history, and commune of residence. In the final combined analysis, participants in the highest quartile of serum Tg, compared to those in the lowest quartile, had adjusted Hazard Ratios of 0.88 (95% confidence interval 0.50–1.52), 1.14 (0.63–2.05), and 0.78 (0.47–1.31) for GNCA, GCA, and ESCC, respectively. Using serum Tg, a sensitive biomarker of iodine deficiency, we found no association between serum Tg concentrations and risk of these upper gastrointestinal (UGI) cancers in the study population. Our results do not support the hypothesis that iodine deficiency, as assessed by serum Tg, is associated with an increased risk of UGI cancers.
iodine deficiency; esophageal cancer; gastric cancer; thyroglobulin; China
Background & Aims
Regular use of aspirin and other non-steroidal anti-inflammatory drugs (NSAID) has been reported to reduce risks for esophageal adenocarcinoma (EAC) and esophagogastric junctional adenocarcinoma (EGJA). However, individual studies have been too small to accurately assess the effects of medication type, frequency, or duration of use. We performed a pooled analysis to investigate these associations.
We performed a pooled analysis of 6 population-based studies within the Barrett's and Esophageal Adenocarcinoma Consortium to evaluate the association between NSAID use and the risk of EAC and EGJA, using uniform exposure definitions. We collected information from 6 studies (5 case-control and 1 cohort), with a total of 1226 EAC and 1140 EGJA cases, on aspirin and/or NSAID use. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate adjusted logistic regression models and then pooled using a random effects meta-analysis model.
Compared to non-users, individuals who have used NSAIDs had a statistically significant, reduced risk of EAC (OR=0.68; 95% CI, 0.56–0.82); they also appeared to have a reduced risk of EGJA (OR=0.84; 95% CI, 0.68–1.03). Similar reductions in risk were observed among individuals who took aspirin or non-aspirin NSAIDs. The highest levels of frequency (≥daily) and duration (≥10 years) of NSAID use were associated with an approximately 40% reduction in risk for EAC: OR=0.56 (95% CI, 0.43–0.73; P-trend, <.001) and OR=0.63 (95% CI, 0.45–0.90; P-trend, 0.04), respectively.
Although reverse causation could, in part, explain the inverse association observed between NSAID use and EAC risk, pooled analysis indicates a role for NSAIDs in prevention of adenocarcinomas of the esophagus and esophagogastric junction.
BEACON; Esophageal Neoplasm; Stomach Cancer; Anti-Inflammatory Agent
Smoking and alcohol consumption explain little of the risk for upper-gastrointestinal (UGI) cancer in China, where over half of all cases in the world occur.
We evaluated questionnaire-based risk factors for UGI cancers in a case-control study from Shanxi Province, China, including 600 esophageal squamous cell carcinomas (ESCC), 599 gastric cardia adenocarcinomas (GCA), 316 gastric noncardia adenocarcinomas (GNCA), and 1514 age- and gender-matched controls.
Ever smoking and ever use of any alcohol were not associated with risk of UGI cancer; only modest associations were observed between ESCC risk and highest cumulative smoking exposure, as well as GNCA risk and beer drinking. While several associations were noted for socioeconomic and some dietary variables with one or two UGI cancers, the strongest and most consistent relations for all three individual UGI cancers were observed for consumption of scalding hot foods (risk increased 150% to 219% for daily vs never users) and fresh vegetables and fruits (risk decreased 48% to 70% for vegetables and 46% to 68% for fruits, respectively, for high vs low quartiles).
This study confirms the minor role of tobacco and alcohol in UGI cancers in this region, and highlights thermal damage as a leading etiologic factor.
smoking; alcohol; socioeconomic status; diet
While gastric noncardia adenocarcinoma (GNCA) incidence rates in the US have decreased, the rates of gastric cardia adenocarcinoma (GCA) and esophageal adenocarcinoma (EADC) have increased. Obesity increases the risks of GCA and EADC, and the associations may be partially mediated by insulin resistance. A few case-control studies have shown an association between diabetes and an increased risk of EADC.
We prospectively examined the association between diabetes and upper gastrointestinal (UGI) cancers in a cohort of 469,448 people in the US, ages 50-71 at baseline. Cox proportional hazards regression was used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for diabetes and UGI cancers, controlling for multiple potential confounders, including body mass index (BMI).
We observed no association of self-reported diabetes with risk of EADC, HR (95%CI) = 0.98 (0.73-1.31), esophageal squamous cell carcinoma (ESCC), HR (95%CI) = 1.02 (0.60-1.74), or GNCA, HR (95%CI) = 0.98 (0.70-1.37). However, diabetes was significantly associated with an increased risk of GCA, HR (95%CI) = 1.89 (1.43-2.50). The significant association between diabetes and risk of GCA remained after adjustment for BMI, HR (95%CI) = 1.70 (1.28-2.26) and did not differ by BMI strata (pinteraction =0.83). The significant association was unchanged when restricting to only overweight subjects (BMI 25 - ≤30), HR (95%CI) = 1.83 (1.18-2.85).
We found a significant association between self-reported diabetes and increased risk of GCA.
Our results suggest that the metabolic and hormonal changes related to diabetes may play a role in the etiology of GCA independently from BMI.
Esophageal adenocarcinoma; gastric adenocarcinoma; diabetes; BMI
Background and aims
Alcohol intake is a strong and well-established risk factor for esophageal squamous cell carcinoma (ESCC), but the association with esophageal adenocarcinoma (EA) or adjacent tumors of the esophagogastric junction (EGJA), remains unclear. Therefore, we determined the association of alcohol intake with ESCC, EA, and EGJA in nine case-control studies and two cohort studies of the Barrett’s Esophagus and Esophageal Adenocarcinoma Consortium (BEACON).
Materials and methods
We collected information on alcohol intake, age, sex, education, body mass index, gastroesophageal reflux, and tobacco smoking from each study. Along with 10,854 controls, 1,821 EA, and 1,837 EGJA, seven studies also collected ESCC cases (n=1,016). Study-specific odds ratios (OR) and 95% confidence intervals (CI) were calculated from multivariate-adjusted logistic regression models for alcohol intake in categories compared to non-drinkers. Summary risk estimates were obtained by random effects models.
We observed no increase in risk of EA or EGJA for increasing levels of any of the alcohol intake measures examined. ORs for the highest frequency category (≥7 drinks per day) were 0.97 (95% CI = 0.68-1.36) for EA and 0.77 (95% CI = 0.54-1.10) for EGJA. Suggestive findings linked moderate intake (e.g. 0.5 to <1 drinks per day) to decreased risk of EA (OR = 0.63 95% CI = 0.41-0.99) and EGJA (OR = 0.78; 95% CI = 0.62-0.99). In contrast, alcohol intake was strongly associated with increased risk of ESCC (OR for ≥7 drinks per day= 9.62, 95%CI=4.26-21.71).
In contrast to ESCC, higher alcohol consumption was not associated with increased risk of either EA or EGJA. The apparent inverse association observed with moderate alcohol intake should be evaluated in future prospective studies.
Alcohol Drinking; Esophageal Neoplasms; Stomach Neoplasms; Epidemiology
A few studies have indicated inverse relationships between serum ghrelin and gastric and esophageal cancers but those associations have been restricted to specific populations, including smokers and overweight individuals. We examined the association between ghrelin and gastroesophageal cancers and atrophic gastritis in a population-based setting.
In total 220 gastroesophageal cancers, comprising non-cardia and cardia gastric cancer, esophageal adenocarcinoma, esophageal squamous cell carcinoma (SCC) and age and gender-matched controls were recruited. Serum ghrelin, pepsinogen I/II ratio (PGI/II) and anti-H.pylori IgG antibodies were measured. Relationships between ghrelin and gastroesophageal cancers, after adjustment for PGI/II ratio, H.pylori status and smoking, were tested using logistic regression. Furthermore, in 125 endoscopically normal volunteers, with and without histological atrophic gastritis, the relationship with ghrelin was compared.
Serum ghrelin (lowest vs. highest quintile) was inversely associated with gastric cancer: OR (95% CI) 8.71 (1.70–44.59) for cardia and 6.58 (1.26–34.46) for non-cardia cancer. Lower serum ghrelin was also associated with esophageal SCC: OR (95% CI) 5.69 (1.36–23.78), but not with esophageal adenocarcinoma. A similar association was observed between gastric cancer (cardia and non-cardia) and esophageal SCC when serum ghrelin was analysed as a continuous scaled variable. In endoscopically-normal volunteers, extensive atrophic gastritis was associated with low serum ghrelin [OR (95% CI) 0.25 (0.10–0.64)].
Inverse associations between ghrelin and some gastroesophageal cancers suggest a potential role for serum ghrelin as a biomarker of upper gastrointestinal cancers and atrophic gastritis. In areas with a high incidence of gastric and/or esophageal cancer, screening might be more effectively targeted to individuals with low serum ghrelin in addition to the PGI/II ratio.
Ghrelin is an orexigenic gut peptide produced predominantly by the stomach. Gastric mucosal ghrelin production could be compromised by an infiltrating adenocarcinoma.
To assess the expression of ghrelin mRNA and peptide in oesophagogastric adenocarcinomas and adjacent non‐neoplastic mucosa.
10 gastric and 22 oesophageal adenocarcinoma archival samples were randomly selected from a database. The presence of ghrelin‐positive cells was assessed in cancer and corresponding non‐neoplastic mucosa by immunohistochemistry. Quantitative reverse transcriptase polymerase chain reaction (PCR) for ghrelin mRNA was also performed on 24 gastric and 8 oesophageal adenocarcinoma specimens and adjacent non‐neoplastic mucosa.
Immunohistochemistry and reverse transcriptase PCR confirm a negligible expression of ghrelin in adenocarcinoma specimens. By contrast, non‐neoplastic gastric mucosa was rich in ghrelin‐positive cells and ghrelin mRNA. The number (median and range) of ghrelin‐positive cells per 2 mm section of non‐neoplastic mucosa was 73 (45–215) in the corpus; this was significantly higher than in cardia mucosa (9 (0–64), p<0.001) and antral mucosa (5 (0–14), p<0.001).
Gastric and oesophageal adenocarcinomas have no ghrelin‐producing cells. The highest level of ghrelin expression was noted in the non‐neoplastic mucosa of the gastric corpus. Disruption of the gastric ghrelin‐producing mechanism may occur during oesophagogastric malignancy.
We investigated the association of dietary α-tocopherol, γ-tocopherol, and supplemental vitamin E intake with the risk of esophageal squamous cell carcinoma (ESCC; n = 158), esophageal adenocarcinoma (EAC; n = 382), gastric cardia adenocarcinoma (GCA; n = 320), and gastric noncardia adenocarcinoma (GNCA; n = 327) in the NIH-AARP Diet and Health Study, a cohort of approximately 500,000 people. Data on dietary and supplemental vitamin E intake were collected using a validated questionnaire at baseline and were analyzed using Cox regression models. Intakes were analyzed as continuous variables and as quartiles.
For dietary α-tocopherol, we found some evidence of association with decreased ESCC and increased EAC risk in the continuous analyses, with adjusted hazard ratios (HR) and 95% confidence intervals (CI) of 0.90 (0.81 – 0.99) and 1.05 (1.00 – 1.11), respectively, per 1.17 mg (half the interquartile range) increased intake. However, in quartile analyses, the p-value for trend was non-significant for both of these cancers. There was no association between dietary α-tocopherol and GCA or GNCA. We observed no statistically significant associations with γ-tocopherol. For supplemental vitamin E, the results were mainly null, except for a significantly lower risk of GNCA with higher doses of supplemental vitamin E. An increase of 71 mg/day (half the interquartile range) in supplemental vitamin E had an HR (95% CI) of 0.92 (0.85–1.00) and the p-value for trend in the quartile analyses was 0.015.
Ghrelin is primarily secreted from the stomach and has been implicated in the coordination of eating behavior and weight regulation. Ghrelin also plays an essential role in the mechanism of gastric mucosal defense. Thus, it is important to clarify which diseases primarily influence changes in plasma ghrelin concentrations. Helicobacter pylori (H pylori) infection is involved in the pathogenesis of gastritis, gastric and duodenal ulcer, gastric carcinoma, and mucosa-associated lymphoid tissue lymphoma. H pylori eradication is related to body weight change. Compared, H pylori infected and negative subjects with normal body mass index, plasma ghrelin concentration, gastric ghrelin mRNA, and the number of ghrelin producing cells in gastric mucosa are significantly lower in H pylori infected subjects than in H pylori-negative controls. Plasma ghrelin concentration decreases with the progression of gastric atrophy. Impaired gastric ghrelin production in association with atrophic gastritis induced by H pylori infection accounts for the decrease in plasma ghrelin concentration. However, the ratio of plasma acylated ghrelin to total ghrelin levels is higher in patients with chronic atrophic gastritis than in healthy subjects. This may result from the compensatory increase in plasma active ghrelin concentration in response to gastric atrophy. After H pylori eradication, gastric preproghrelin mRNA expression is increased nearly 4-fold in most cases. However, changes in plasma ghrelin concentrations before and after H pylori cure are not associated with the gastric ghrelin production. Plasma ghrelin changes are inversely correlated with both body weight change and initial plasma ghrelin levels.
Ghrelin; Helicobacter pylori; Eradication; Body weight; Leptin
Cigarette smoking is associated with esophageal adenocarcinoma (EAC), esophagogastric junctional adenocarcinoma (EGJA) and esophageal squamous cell carcinoma (ESCC), and alcohol consumption with ESCC. However, no analyses have examined how delivery rate modifies the strength of odds ratio (OR) trends with total exposure, i.e., the impact on the OR for a fixed total exposure of high exposure rate for short duration compared with low exposure rate for long duration.
The authors pooled data from 12 case-control studies from the Barrett’s Esophagus and Esophageal Adenocarcinoma Consortium (BEACON), including 1,242 (EAC), 1,263 (EGJA) and 954 (ESCC) cases and 7,053 controls, modeled joint ORs for cumulative exposure and exposure rate for cigarette smoking and alcohol consumption, and evaluated effect modification by sex, body mass index (BMI), age and self-reported acid reflux.
For smoking, all sites exhibited inverse delivery rate effects, whereby ORs with pack-years increased, but trends weakened with increasing cigarettes/day. None of the examined factors modified associations, except for ESCC where younger ages at diagnosis enhanced smoking effects (P<0.01). For EAC and EGJA, ORs with drink-years exhibited inverse associations in <5 drinks/day consumers and no association in heavier consumers. For ESCC, ORs with drink-years increased, with trends strengthening with greater drinks/day. There was no significant effect modification, except for EAC and EGJA where acid reflux mitigated the inverse associations (P=0.02). For ESCC, younger ages at diagnosis enhanced drinking-related ORs (P<0.01).
Patterns of ORs by pack-years and drink-years, delivery rate effects and effect modifiers revealed common as well as distinct etiologic elements for these diseases.
alcohol drinking; risk model; smoking
A 75-year-old man underwent endoscopic hemostatic therapy for hemorrhagic gastric ulcer in September 2002. After healing of the gastric ulcer, he underwent Helicobacter pylori eradication therapy in February 2003. In August 2007, an irregular tumor was detected in the lower esophagus at annual checkup for gastric cancer screening using X-ray. Endoscopic examination showed that the lower margin of the tumor almost coincided with the esophagogastric junction and that a short segment of Barrett's epithelium existed near the tumor. Biopsies of the tumor showed moderately to poorly differentiated adenocarcinoma. Mild reflux esophagitis and minor hiatal hernia was also observed, and the previously treated gastric ulcer was not recurrent. Absence of H. pylori was confirmed by serum antibody and urea breath test. Surgical resection of the lower esophagus and proximal stomach was performed. The tumor invaded into the muscularis propria of the esophageal wall but had no evidence of lymph node metastasis. Based on macroscopic and pathological findings, the tumor was recognized as esophageal adenocarcinoma. Previous endoscopic examination did not detect any apparent signs of tumor in the esophagogastric junction. As far as we know, this is the first report documenting a newly developed esophageal adenocarcinoma after the successful eradication of H. pylori.
Helicobacter pylori eradication; Esophageal adenocarcinoma
Esophagogastric junctional (EGJ) cancer occurs in the mucosa near the esophagogastric junction, and has characteristics of both esophageal and gastric malignancies; its optimal treatment strategy is controversial.
We conducted a single-center retrospective cohort study of the patients who underwent curative surgery with lymphadenectomy for EGJ cancer. Tumor specimens were categorized by histology and location into four types—centered in the esophagus < 5 cm from EGJ (type E), which were subtyped as (i) squamous-cell carcinoma (SQ) or (ii) adenocarcinoma (AD); (iii) any histological tumor centered in the stomach < 5 cm from EGJ, with EGJ invasion (type Ge); (iv) any histological tumor centered in the stomach < 5 cm from EGJ, without EGJ invasion (type G)—and classified by TNM system; these were compared to patients’ clinicopathological characteristics and survival outcomes.
A total of 92 EGJ cancer patients were studied. Median follow-up of surviving patients was 35.5 months. Tumors were categorized as 12 type E (SQ), 6 type E (AD), 27 type Ge and 47 type G; of these 7 (58.3%), 3 (50%), 19 (70.4%) and 14 (29.8%) and 23 patients, respectively, had lymph node metastases. No patients with type E (AD) and Ge tumors had cervical lymph node metastasis; those with type G tumors had no nodal metastasis at cervical and mediastinal lymph nodes. Multivariate analysis showed that type E (AD) tumor was an independent prognostic factor.
We should distinguish type Ge tumor from type E (AD) tumor because of the clinicopathological and prognostic differentiation. Extended gastrectomy with or without lower esophagectomy according to tumor location and lower mediastinal and abdominal lymphadenectomy are recommended for EGJ cancer.
University Hospital Medical Information Network in Japan, UMIN000008596.
Esophagogastric junctional cancer; Esophageal cancer; Gastric cancer; Lymph node metastasis
Ghrelin, an orexigenic gut hormone secreted primarily from the stomach, is involved in energy homeostasis. However, little data is available regarding its response to energy surplus and the development of human obesity.
The present study investigated the response of circulating acylated ghrelin to a 7-day positive energy challenge.
A total of 68 healthy young men were overfed 70% more calories than required, for 1-week. Subjects were classified based on percent body fat (measured by dual-energy X-ray absorptiometry) as normal weight, overweight, and obese. Serum acylated ghrelin concentration was measured before and after the positive energy challenge. Additionally, the relationship between acylated ghrelin and obesity-related phenotypes including weight, body mass index, percent body fat, cholesterol, HDL-c, LDL-c, glucose, insulin and homeostasis model assessment of insulin resistance and β-cell function at baseline and change due to overfeeding, were assessed.
Contrary to our expectations, serum acylated ghrelin was significantly increased in response to overfeeding and the increase was independent of obesity status. There was no significant difference in fasting acylated ghrelin between normal weight, overweight, and obese men at baseline. Acylated ghrelin was negatively correlated with weight and BMI for normal weight and with BMI in overweight men. Also ghrelin was correlated with change in weight and BMI in overweight (negative relationship) and obese (positive relationship) groups.
Our results showed that circulating acylated ghrelin was increased after a 7-day positive energy challenge regardless of adiposity status. However, acylated ghrelin was correlated with change in weight and BMI in opposing directions, in overweight and obese subjects respectively, thus dependent on obesity status.
The relationship between Helicobacter pylori infection and ghrelin is controversial. We compared ghrelin levels in gastric mucosa and plasma between H. pylori-positive and -negative subjects, and between before and after H. pylori eradication.
We compared the ghrelin levels in the antrum, body, and fundus between H. pylori-positive and -negative subjects; in stomach tissues between before and after H. pylori eradication; and in plasma and tissue in 10-person cohorts between before and after H. pylori eradication therapy. Body mass index, age, and sex were controlled for when comparing ghrelin levels.
Stomach ghrelin levels (in the antrum, body, and fundus) did not differ significantly between H. pylori-positive and -negative samples (p=0.095, 0.316, and 0.897, respectively), or between before and after H. pylori eradication (p=0.19, 0.178, and 0.513, respectively). In the ten-person cohort study, plasma ghrelin levels in the eight H. pylori-positive subjects were 2,260 pg/mL (range, 1,280-3,770 pg/mL) and 1,900 pg/mL (range, 1,350-5,200 pg/mL) before and after eradication therapy (p=0.871). Stomach ghrelin levels did not differ significantly in the eight H. pylori-positive subjects between before and after H. pylori eradication (p=0.732, 0.618, and 0.435 in the antrum, body, and fundus, respectively), or between six eradicated and two noneradicated subjects (p=0.071, 0.857, 0.429, and 0.857 in the antrum, body, fundus, and plasma, respectively).
These results show that H. pylori infection has no effect on stomach ghrelin levels and that eradication therapy does not influence plasma or tissue ghrelin levels.
Helicobacter pylori; Ghrelin; Eradication
Background. This study addresses clinicopathological differences between patients with gastric cardia and subcardial cancer with and without esophagogastric junctional invasion. Methods. We performed a single-center, retrospective cohort study. We studied patients who underwent curative surgery for gastric cardia and subcardial cancers. Tumors centered in the proximal 5 cm of the stomach were classed into two types, according to whether they did (Ge) or did not (G) invade the esophagogastric junction. Results. A total of 80 patients were studied; 19 (73.1%) of 26 Ge tumors and 16 (29.6%) of 54 G tumors had lymph nodes metastases. Incidence of nodal metastasis in pT1 tumors was significantly higher in the Ge tumor group. No nodal metastasis in cervical lymph nodes was recognized. Only two patients with Ge tumors had mediastinal lymph node metastases. Incidence of perigastric lymph node metastasis was significantly higher in those with Ge tumors. Ge tumors tended to be staged as progressive disease using the esophageal cancer staging manual rather than the gastric cancer staging manual. Conclusion. Because there are some differences in clinicopathological characteristics, it is thought to be adequate to distinguish type Ge from type G tumor.
Ghrelin is an orexigenic peptide hormone produced mainly by a distinct group of dispersed endocrine cells located within the gastric oxyntic mucosa. Besides secreted gene products derived from the preproghrelin gene, which include acyl-ghrelin, desacyl-ghrelin and obestatin, ghrelin cells also synthesize the secreted protein nesfatin-1. The main goal of the current study was to identify other proteins secreted from ghrelin cells. An initial gene chip screen using mRNAs derived from highly enriched pools of mouse gastric ghrelin cells demonstrated high levels of serum retinol-binding protein (RBP4) and transthyretin (TTR), both of which are known to circulate in the bloodstream bound to each other. This high expression was confirmed by quantitative RT-PCR using as template mRNA derived from the enriched gastric ghrelin cell pools and from two ghrelin-producing cell lines (SG-1 and PG-1). RBP4 protein also was shown to be secreted into the culture medium of ghrelin cell lines. Neither acute nor chronic caloric restriction had a significant effect on RBP4 mRNA levels within stomachs of C57BL/6J mice, although both manipulations significantly decreased stomach TTR mRNA levels. In vitro studies using PG-1 cells showed no effect on RBP4 release of octanoic acid, epinephrine or norepinephrine, all of which are known to act directly on ghrelin cells to stimulate ghrelin secretion. These data provide new insights into ghrelin cell physiology, and given the known functions of RBP4 and TTR, support an emerging role for the ghrelin cell in blood glucose handling and metabolism.
Epidemiological data on green/jasmine tea and esophageal as well as gastric cancer are limited and inconclusive. In order to study the effect of jasmine tea in upper gastrointestinal (UGI) cancers, we evaluated 600 esophageal squamous cell carcinoma (ESCC), 598 gastric cardia adenocarcinoma (GCA), and 316 gastric non-cardia adenocarcinoma (GNCA) cases and 1514 age-, gender-, and neighborhood-matched controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated from logistic regression adjusted for matching factors and potential confounders. Among controls, 35% of males and 8% of females reported consumption of jasmine tea; other tea consumption was rare. Consumption of jasmine tea (ever vs. never) was not associated with risk of ESCC (OR=1.15, 95% CI 0.92–1.44), GCA (OR=1.14, 95% CI 0.88–1.37), or GNCA (OR=0.85, 95% CI 0.64–1.15) in males and females combined. Among males, cumulative lifetime consumption showed a significant positive dose-response relation with ESCC risk, but not for GCA and GNCA. In exploratory analyses, occupation affected the relation between tea and ESCC such that consumption in males was associated with increased risk only in non-office workers. Overall, we found no evidence for a protective effect of tea in esophageal or gastric cancer. Further studies of the potential effects of thermal damage, tea quality, and water quality on UGI cancers are suggested.
jasmine tea; esophageal cancer; gastric cancer
Despite declining incidence rates, gastric cancer (GC) is a major cause of death worldwide. Its aetiology may involve dietary antioxidant micronutrients such as carotenoids and tocopherols. The objective of this study was to determine the association of plasma levels of seven common carotenoids, their total plasma concentration, retinol and α- and γ-tocopherol, with the risk of gastric adenocarcinoma in a case–control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC), a large cohort involving 10 countries. A secondary objective was to determine the association of total sum of carotenoids, retinol and α-tocopherol on GCs by anatomical subsite (cardia/noncardia) and histological subtype (diffuse/intestinal). Analytes were measured by high-performance liquid chromatography in prediagnostic plasma from 244 GC cases and 645 controls matched by age, gender, study centre and date of blood donation. Conditional logistic regression models adjusted by body mass index, total energy intake, smoking and Helicobacter pylori infection status were used to estimate relative cancer risks. After an average 3.2 years of follow-up, a negative association with GC risk was observed in the highest vs the lowest quartiles of plasma β-cryptoxanthin (odds ratio (OR)=0.53, 95% confidence intervals (CI)=0.30–0.94, Ptrend=0.006), zeaxanthin (OR=0.39, 95% CI=0.22–0.69, Ptrend=0.005), retinol (OR=0.55, 95% CI=0.33–0.93, Ptrend=0.005) and lipid-unadjusted α-tocopherol (OR=0.59, 95% CI=0.37–0.94, Ptrend=0.022). For all analytes, no heterogeneity of risk estimates or significant associations were observed by anatomical subsite. In the diffuse histological subtype, an inverse association was observed with the highest vs lowest quartile of lipid-unadjusted α-tocopherol (OR=0.26, 95% CI=0.11–0.65, Ptrend=0.003). These results show that higher plasma concentrations of some carotenoids, retinol and α-tocopherol are associated with reduced risk of GC.
carotenoids; tocopherol; retinol; gastric cancer; diet; EPIC
Oxidative stress is a major cause of the gastrointestinal damage under physical or psychological stress. Ghrelin exhibits gastroprotective effects and they are supposed to be derived from antioxidant effects. In gastroduodenal mucosal injury, the plasma ghrelin levels increase in response to the demand for gastroduodenal cytoprotection. However, in the condition of Helicobacter pylori-induced gastric mucosal severe atrophy, the plasma ghrelin concentration shifted to lower levels. In diabetic gastroparesis, the regulation of ghrelin secretion is impaired with vagal nerve dysfunction. Selective ghrelin agonist is expected to represent a new class of prokinetic agent. In addition, the plasma ghrelin levels are also enhanced by systemic oxidative stress, and ghrelin exhibits antioxidant effects in many organs, such as heart, pancreas, and lung. This suggests that ghrelin would be an important player as a sensor of systemic oxidative stress.
oxidative stress; ghrelin; peptic ulcer; gastroparesis
Esophagogastric (EG) adenocarcinomas are aggressive malignancies. Although uncommon in the United States, gastric cancer is endemic in East Asia. In this review we focus on perioperative strategies for locally advanced EG adenocarcinomas.
We summarized the results of completed phase III trials of perioperative therapy for locally advanced adenocarcinomas of the esophagus, gastroesophageal (GE) junction, or stomach. We also reviewed ongoing clinical trials.
In the adjuvant setting following surgery, validated approaches include chemoradiation with a fluoropyrimidine or chemotherapy (using a fluoropyrimidine with or without platinum compound). In the neoadjuvant setting, some trials have shown a benefit for perioperative chemotherapy. Trials in esophageal and GE junction adenocarcinomas have also shown improved outcomes with preoperative chemoradiation, which, on the basis of a phase III trial and large meta-analysis, may be superior to preoperative chemotherapy. Changes on positron emission tomography (PET) scans following chemotherapy or chemoradiation have been shown to be prognostic, and the use of PET imaging to guide the choice of chemotherapy with concurrent radiation is being evaluated. Other trials are combining targeted therapies with standard treatments.
Numerous adjuvant and pre-/perioperative strategies have now been shown to improve survival by approximately 15% compared to surgery alone. Ongoing trials will hopefully clarify the relative superiority of such approaches, the ability of PET to direct therapy, and the role of targeted agents in treating locally advanced tumors.
Low serum pepsinogen I (PGI) and low pepsinogen I/pepsinogen II ratio (PGI/II ratio) are markers of gastric fundic atrophy. We aimed to prospectively test the association between serum PGI/II ratio and risks of gastric noncardia adenocarcinoma, gastric cardia adenocarcinoma, and esophageal squamous cell carcinoma.
Case-cohort study nested in a prospective cohort with over 15 years of follow-up.
Rural region of the People’s Republic of China.
Men and women aged 40-69 at study baseline.
Main outcome measures
Adjusted hazard ratios and 95% confidence intervals for the association between serum PGI/II ratio and caner risk
Compared to subjects with PGI/II ratio of > 4, those with ≤4 had HRs (95%CIs) of 2.72 (1.77-4.20) and 2.12 (1.42-3.16) for noncardia and cardia gastric cancers, respectively. Risk of both cancers were also increased when other cut points ranging from 3 to 6, or when we used quartile models, or nonlinear continuous models. Risk of ESCC was marginally increased in those with PGI/II ratio ≤4, with HR (95% CI) of 1.56 (0.99-2.47), but quartile models and continuous models showed no increased risk. The nonlinear continuous models suggested that any single cut point collapsed subjects with dissimilar gastric cancer risks, and that using cut points was not an efficient use of data in evaluating these associations.
In this prospective study, we found similar and significantly increased risks of noncardia and cardia gastric adenocarcinomas in subjects with low PGI/II ratio, but little evidence for an association with ESCC risk.
Gastric cancer; Esophageal cancer; Pepsinogen; Case-cohort
Ghrelin, a 28-amino-acid gastric peptide hormone, has an appetite-stimulating effect and controls the energy balance. Serum ghrelin levels inversely correlate with body mass index. Recently, several papers reported the ethnic difference in the ghrelin levels. To our knowledge, however, no studies have compared the serum ghrelin levels between Caucasian in the United States (U.S.) and the Japanese in Japan.
We conducted a cross-sectional study of 189 men 40-49 years of age (91 Caucasian in the U.S. and 98 Japanese in Japan) to examine serum ghrelin levels and metabolic and other factors.
Serum ghrelin levels correlated with waist circumferences and lipid profiles among Caucasian American and the Japanese. Serum ghrelin levels were significantly higher among Caucasian Americans than among the Japanese (904.5 (632.0, 1132.0) pg/mL, 508.0 (399.0, 1378.3) pg/mL (median and 95% confidence interval), respectively, P<0.01), although Caucasian Americans were much more obese (BMI: 26.9±3.3 kg/m2 versus 23.3±3.1kg/m2 respectively, P<0.01). The ethnic difference remained after adjusting for metabolic factors, smoking status, and other factors (P<0.01).
We have shown in our population-based study that serum ghrelin levels among men aged 40-49 are significantly higher in Caucasian Americans than in the Japanese in Japan. Reasons for the ethnic difference in the ghrelin levels are largely unknown and warrant further investigation.
gut hormones; ghrelin; ethinic difference
We prospectively examined the relation between pretrial serum vitamin D status and risk of oesophageal and gastric cancers among subjects who developed cancer over 5.25 years of follow-up, including 545 oesophageal squamous cell carcinomas (ESCC), 353 gastric cardia adenocarcinomas, 81 gastric noncardia adenocarcinomas, and an age- and sex-stratified random sample of 1105 subjects. The distribution of serum 25(OH)D was calculated using the known sampling weights. For the cohort as a whole, the 25th, 50th, and 75th percentile concentrations of 25(OH)-vitamin D were 19.6, 31.9, and 48.7 nmol l−1, respectively, and we found that higher serum 25(OH)D concentrations were associated with monotonically increasing risk of ESCC in men, but not in women. Comparing men in the fourth quartile of serum 25(OH)D concentrations to those in the first, we found a hazard ratio (HR) (95% confidence interval (CI)) of 1.77 (1.16–2.70), P trend=0.0033. The same comparison in women had a HR (95% CI) of 1.06 (0.71–1.59), P trend=0.70. We found no associations for gastric cardia or noncardia adenocarcinoma. Among subjects with low vitamin D status, higher serum 25(OH)D concentrations were associated with significantly increased risk of ESCC in men, but not in women. Further refinements of the analysis did not suggest any factors, which could explain this unexpected result.
vitamin D; oesophageal cancer; gastric cancer; cohort study; China
Ghrelin, the natural ligand for the growth hormone (GH)-secretagogue receptor (GHS-R), is produced predominantly in the stomach. It is present in the circulation in two major forms, an acylated and an unacylated form, both of which have reported activities. Some of the best understood main effects of acylated ghrelin administration include anorexic effects, increased appetite and the stimulation of GH secretion. Ghrelin also seems to plays a role in glucose homeostasis, lipid metabolism and immune function. Based on its orexigenic and metabolic effects, ghrelin and ghrelin mimetics have potential benefit in antagonizing protein breakdown and weight loss in catabolic conditions such as cancer cachexia, renal, cardiac and pulmonary disease, and age-related frailty. Ghrelin also has potentially useful positive effects on cardiac function and gastric motility. Ghrelin antagonists may be of benefit to increase insulin sensitivity and potentiate weight loss. The following chapter presents some background on ghrelin and ghrelin assays and discusses some of the potential therapeutic approaches for the use of ghrelin, ghrelin mimetic compounds and ghrelin antagonists in clinical disease.
ghrelin; growth hormone; ghrelin-mimetics; aging