Body mass index and risk of adenocarcinomas of the esophagus and gastric cardia

Effect of mirtazapine on MNNG-induced gastric adenocarcinoma in rats

OBJECTIVE

In this study, anticancer effects of mirtazapine on rats were investigated in an adenocarcinoma model induced by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and compared with those of cisplatin.

MATERIALS AND METHODS

For this purpose, 10 mg/kg doses of mirtazapine were administered orally to one group of rats, while 1 mg/kg doses of cisplatin were administered intraperitoneally to another group. At 1 hour after administration, 200 mg/kg doses of MNNG were given orally to both groups. MNNG administration was repeated once every 10 days through 3 months, after which period, gastric tissue was taken and pathologically evaluated.

RESULTS

Mirtazapine prevented adenocarcinoma induction by MNNG in rats to a greater extent than cisplatin. Some of the rats receiving cisplatin demonstrated severe dysplasia in gastric samples and others exhibited mild dysplasia. Rats given mirtazapine were not observed to suffer severe dysplasia, only mild dysplasia being observed.

CONCLUSION

For adenocarcinoma induced by MNNG on rats, mirtazapine was determined more effective than cisplatin. In order to make statement about mechanism of anticancer activity of mirtazapine, wider studies are required.

Body mass index and risk of gastric cancer: a meta-analysis of a population with more than ten million from 24 prospective studies

BACKGROUND

To provide a quantitative assessment of the association between body mass index (BMI) and the risk of gastric cancer, we summarized the evidence from prospective studies.

METHODS

Eligible studies published up to November 30, 2012, were retrieved via computer searches of MEDLINE and EMBASE as well as manual review of references. Summary relative risks (SRR) with their corresponding 95% confidence intervals (CI) were calculated using a random-effects model.

RESULTS

A total of 24 prospective studies of BMI and gastric cancer risk with 41,791 cases were included in our analysis. Overall, both overweight (BMI, 25-30 kg/m(2)) and obesity (BMI, ≥30 kg/m(2)) were not associated with risk of total gastric cancer (overweight: SRR, 1.01; 95% CI, 0.96-1.07; obesity: SRR, 1.06; 95% CI, 0.99-1.12). Furthermore, we found increased BMI was positively associated with the risk of gastric cardia cancer (GCC; SRR = 1.21 for overweight and 1.82 for obesity), but not with gastric non-cardia cancer (GNCC; SRR = 0.93 for overweight and SRR = 1.00 for obesity). Similar results were observed in a linear dose-response analysis.

CONCLUSION

On the basis of meta-analysis of prospective studies, we find high BMI is positively associated with the risk of GCCs but not with GNCCs.

IMPACT

(i) On the basis of more definite and quantitative evidence than previously available, we found that increasing BMI was not a clear risk factor for total gastric cancer. (ii) Increased BMI was positively associated with risk of GCC but not with GNCCs.

Risk factors for esophageal adenocarcinoma after antireflux surgery

OBJECTIVES

Gastroesophageal reflux is the main risk factor for esophageal adenocarcinoma, but there is no strong support for any cancer-protective effect after antireflux surgery. We hypothesized that recurrent reflux or high exposure to other established risk factors, that is, obesity and tobacco smoking, are overrepresented among patients who despite antireflux surgery develop esophageal adenocarcinoma.

DESIGN

A population-based case-control study was nested within an antireflux surgery cohort from the Swedish Patient Register between 1965 and 2006. Cases were patients who developed esophageal adenocarcinoma more than 5 years after antireflux surgery, whereas randomly selected controls were matched to the cases regarding age, sex, and calendar year of the antireflux surgery. Study exposures among cases and controls were collected through review of medical records. Data on cancer were assessed through the Swedish Cancer Register. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using multivariable conditional logistic regression, adjusted for recurrent reflux, body mass index (BMI), tobacco smoking, and type of antireflux surgery.

RESULTS

From 14,102 patients in the total antireflux surgery cohort, 55 cases and 240 controls were included. Patients who developed esophageal adenocarcinoma were 3 times more likely to have recurrent reflux after their antireflux surgery, compared with those who had not (OR: 3.1, 95% CI: 1.5-6.3). There were no statistically significant differences in risk when comparing BMI of 30 kg/m or more with BMI of less than 25 kg/m (OR: 1.6, CI: 0.8-3.5), ever smokers with never smokers (OR: 1.4, 95% CI: 0.7-2.8), or total fundoplication with partial fundoplication (OR: 0.6, 95% CI: 0.3-1.3).

CONCLUSIONS

Recurrence of reflux might explain the lack of protective effect of antireflux surgery regarding risk of developing esophageal adenocarcinoma.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, The Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Screening and risk stratification for Barrett's esophagus: how to limit the clinical impact of the increasing incidence of esophageal adenocarcinoma

Barrett's esophagus (BE) and gastroesophageal reflux disease are the strongest risk factors for esophageal adenocarcinoma. To reduce the clinical impact of this disease, endoscopic screening to detect BE has been proposed and nonendoscopic diagnostic techniques are under investigation. Because screening would result in new diagnoses of BE and additional costs related to endoscopic surveillance, novel tools for risk stratification are also warranted. Dysplasia is the gold standard for risk stratification. Molecular biomarkers may provide a more objective and reproducible estimation of the individual risk, and further prospective studies are required as a prelude to introducing biomarkers into routine clinical practice.

Clinical practice guidelines for the perioperative nutritional, metabolic, and nonsurgical support of the bariatric surgery patient--2013 update: cosponsored by American Association of Clinical Endocrinologists, the Obesity Society, and American Society for Metabolic & Bariatric Surgery

The development of these updated guidelines was commissioned by the AACE, TOS, and ASMBS Board of Directors and adheres to the AACE 2010 protocol for standardized production of clinical practice guidelines (CPG). Each recommendation was re-evaluated and updated based on the evidence and subjective factors per protocol. Examples of expanded topics in this update include: the roles of sleeve gastrectomy, bariatric surgery in patients with type-2 diabetes, bariatric surgery for patients with mild obesity, copper deficiency, informed consent, and behavioral issues. There are 74 recommendations (of which 56 are revised and 2 are new) in this 2013 update, compared with 164 original recommendations in 2008. There are 403 citations, of which 33 (8.2%) are EL 1, 131 (32.5%) are EL 2, 170 (42.2%) are EL 3, and 69 (17.1%) are EL 4. There is a relatively high proportion (40.4%) of strong (EL 1 and 2) studies, compared with only 16.5% in the 2008 AACE-TOS-ASMBS CPG. These updated guidelines reflect recent additions to the evidence base. Bariatric surgery remains a safe and effective intervention for select patients with obesity. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Management of localized gastric cancer

Gastric cancer continues to be a fatal disease with majority of cases presenting in late stages. For patients with advanced disease, we can only recommend palliative therapy. For localized gastric cancer, the approaches vary in various regions of the world. In western countries, preoperative chemotherapy or adjuvant chemo-radiation is preferred; however in Asia, surgery followed by adjuvant chemotherapy is favored. The extent of the lymph node dissection also varies by region. D2 gastrectomy is difficult to implement in most western countries while it is standardized and is a routine in Asia. We recommend multidisciplinary evaluation of each patient before starting any therapy. The prognosis after resection depends of the pathologic stage. Long-term survivors are often <50% in the West and <70% in many Asian countries. Regional and systemic recurrences are common. Improved systemic treatments are needed. Detailed studies of molecular biology might uncover novel therapeutic targets and prognostic subgroups.

The role of tobacco, alcohol, and obesity in neoplastic progression to esophageal adenocarcinoma: a prospective study of Barrett's esophagus

BACKGROUND

Esophageal adenocarcinoma (EA) incidence in many developed countries has increased dramatically over four decades, while survival remains poor. Persons with Barrett's esophagus (BE), who experience substantially elevated EA risk, are typically followed in surveillance involving periodic endoscopy with biopsies, although few progress to EA. No medical, surgical or lifestyle interventions have been proven to safely lower EA risk.

DESIGN

We investigated whether smoking, obesity or alcohol could predict progression to EA in a prospective cohort of 411 BE patients. Data were collected during personal interview. Adjusted hazard ratios (HR) were estimated using Cox regression.

RESULTS

39% had body mass index (BMI) over 30 and 64% had smoked cigarettes. Main analyses focused on those with at least 5 months of follow-up (33,635 person-months), in whom 45 developed EA. Risk increased by 3% per year of age (trend p-value 0.02), with approximate doubling of risk among males. EA risk increased with smoking pack-years (trend p-value 0.04) and duration (p-value 0.05). Compared to never-smokers, the HR for those in the highest pack-year tertile was 2.29 (95%CI 1.04-5.07). No association was found with alcohol or BMI, whereas a suggestion of increased risk was observed in those with higher waist-hip ratio, especially among males.

CONCLUSION

EA risk significantly increased with increasing age and cigarette exposure. Abdominal obesity, but not BMI, was associated with a modest increased risk. Continued follow-up of this and other cohorts is needed to precisely define these relationships so as to inform risk stratification and preventive interventions.

Esophageal cancer characterization with pneumo-64-MDCT

Early diagnosis and accurate staging of esophageal cancer are both essential for therapeutic strategy planning. Endoscopic ultrasound, CT, and positron emission tomography have all been used in the preoperative staging of esophageal cancer separately or in various combinations. Each imaging method has its strengths and weaknesses. Depiction of the tumor's anatomic location conditions the surgical strategy. Endoscopic ultrasound and PET have important advantages but neither provides information for surgical planning. CT scans have some limitations for hollow organ assessment in the absence of lumen distension, since the organ wall may be collapsed. Therefore, optimal esophageal distension could be very useful to overcome these limitations. This potential drawback is crucial at the level of the GE junction, a typically difficult region to evaluate. In order to optimize tumor visualization in the esophageal wall and in the GE junction, we developed a technique named pneumo-64-MDCT. We achieve maximum lumen distension, which better highlights the thickened areas in relation to the normal esophageal wall. At the present time, we have performed 200 studies with this technique and it proved useful, safe and accurate to identify esophageal wall thickening and to stage esophageal cancer. The additional stomach distension led to an adequate definition of both the upper and lower borders of the lesion in tumors located in the GE junction, which in turn was helpful to design the surgical approach.

Human papillomavirus (HPV) infection and the risk of esophageal squamous cell carcinoma

There is currently no consensus on the relationship between human papillomavirus (HPV) infection and the pathogenic process of esophageal squamous cell carcinoma (ESCC). Therefore, a retrospective study was performed to explore the association between HPV infection and ESCC, where 225 patients with diagnosed ESCC and 224 matched controls were enrolled in the study and stratified according to smoking and alcohol consumption. Enzyme-linked immunosorbent assay was used to determine seropositivity to HPV by the detection of either IgG or IgM anti-HPV antibodies. In the non-smoking and non-alcohol-consuming subgroup, the incidence of ESCC of HPV seropositive subjects was similar with that of HPV seronegative subjects (P= 0.737, odds ratio [OR] 1.14, 95% confidence interval [CI] 0.54-2.40). However, in the smoking subgroup, there was a significant difference in the incidence of ESCC between HPV seropositive subjects and HPV seronegative subjects (P= 0.009, OR 2.22, 95% CI 1.22-4.04). In addition, there was a significantly higher association of the development of ESCC in HPV seropositive patients that smoke and drink than those that do not (P < 0.001, OR 10.31, 95% CI 4.04-26.29). Therefore, HPV infection is not an independent risk factor for developing ESCC in the non-smoking and non-alcohol-consuming group. For smokers, however, HPV infection increases the risk of the incidence of ESCC.

Epidemiology and risk factors for gastroesophageal junction tumors: understanding the rising incidence of this disease

Gastroesophageal (GE) junction carcinoma is a rare but often lethal condition with increasing importance as a public health problem in recent decades. Whereas diagnosis of this disease has been complicated historically by the lack of uniform classification standards, available data from the Surveillance, Epidemiology, and End Results cancer registry program in the United States show an approximate 2.5-fold increase in the incidence of GE junction adenocarcinoma from 1973 to 1992, with rates stabilizing in the past 2 decades. Similar proportional trends are observed among subgroups defined by race and gender, but rates are significantly higher in males relative to females, and in white males relative to black males. Smoking, obesity, and GE reflux disease are significant risk factors for GE junction adenocarcinoma, and may account for a substantial fraction of total disease burden. Infection with Helicobacter pylori has been associated with reduced incidence, and high dietary fiber intake has also been linked to lower disease risk. Ongoing studies continue to explore a potential role for nonsteroidal anti-inflammatory drugs in chemoprevention.

Carcinoma of the gastroesophageal junction in Chinese patients

Carcinoma of the gastroesophageal junction (GEJ) is defined as carcinoma that crosses the GEJ line, irrespective of where the tumor epicenter is located. This group of cancer is rare but controversial. Based on study results from the majority of epidemiologic and clinicopathologic investigations carried out in Western countries, this cancer is believed to arise from Barrett’s esophagus (BE) and includes both distal esophageal and proximal gastric carcinomas because of similar characteristics in epidemiology, clinicopathology, and molecular pathobiology in relation to BE. As such, the most recent American Joint Committee on Cancer staging manual requires staging all GEJ carcinomas with the rule for esophageal adenocarcinoma (EA). This mandate has been challenged recently by the data from several studies carried out mainly in Chinese patients. The emerging evidence derived from those studies suggests: (1) both BE and EA are uncommon in the Chinese population; (2) almost all GEJ cancers in Chinese arise in the proximal stomach and show the features of proximal gastric cancer, not those of EA; (3) application of the new cancer staging rule to GEJ cancer of Chinese patients cannot stratify patients’ prognosis effectively; and (4) prognostic factors of GEJ cancer in Chinese are similar, but not identical, to those of EA. In conclusion, the recent evidence suggests that GEJ cancer in Chinese shows distinct clinicopathologic characteristics that are different from EA. Further investigations in molecular pathology may help illustrate the underlying pathogenesis mechanisms of this cancer in Chinese patients and better manage patients with this fatal disease.

Body mass index in relation to oesophageal and oesophagogastric junction adenocarcinomas: a pooled analysis from the International BEACON Consortium

BACKGROUND

Previous studies suggest an association between obesity and oesophageal (OA) and oesophagogastric junction adenocarcinomas (OGJA). However, these studies have been limited in their ability to assess whether the effects of obesity vary by gender or by the presence of gastro-oesophageal reflux (GERD) symptoms.

METHODS

Individual participant data from 12 epidemiological studies (8 North American, 3 European and 1 Australian) comprising 1997 OA cases, 1900 OGJA cases and 11 159 control subjects were pooled. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between body mass index (BMI, kg/m(2)) and the risk of OA and OGJA. Random-effects meta-analysis was used to combine these ORs. We also investigated effect modification and synergistic interaction of BMI with GERD symptoms and gender.

RESULTS

The association of OA and OGJA increased directly with increasing BMI (P for trend <0.001). Compared with individuals with a BMI <25, BMI ≥40 was associated with both OA (OR 4.76, 95% CI 2.96-7.66) and OGJA (OR 3.07, 95% CI 1.89-4.99). These associations were similar when stratified by gender and GERD symptoms. There was evidence for synergistic interaction between BMI and GERD symptoms in relation to OA/OGJA risk.

CONCLUSIONS

These data indicate that BMI is directly associated with OA and OGJA risk in both men and women and in those with and without GERD symptoms. Disentangling the relationship between BMI and GERD will be important for understanding preventive efforts for OA and OGJA.

Comparison of disease-specific survival in the United States and Korea after resection for early-stage node-negative gastric carcinoma

BACKGROUND AND OBJECTIVES

Disease-specific survival (DSS) for GC patients differs in Eastern and Western countries. The aim is to compare outcomes of US and Korean patients following resection of early-stage, node-negative gastric carcinoma (GC).

METHODS

All patients (1995-2005) with T1N0 gastric carcinoma, excluding gastroesophageal tumors, were evaluated. DSS was compared by adjusting for prognostic variables from an internationally validated GC nomogram.

RESULTS

The cohort included 598 Korean patients and 159 US patients. Age and BMI were significantly higher in US patients. Distal tumor location was more frequent in Korea (60% vs. 52%) and proximal location in the US (19% vs. 5%, P < 0.0001). Five-year DSS did not differ significantly between Korea and the US. After multivariate analysis, DSS of Korean patients persisted, with no significant differences when compared to US patients (HR = 1.2, 95% CI: 0.3-5.2, P = 0.83).

CONCLUSIONS

Despite widespread speculations that GC differs in the East and West, when we compare similarly staged, node-negative GC patients, survival did not differ significantly between Korea and the US. This suggests that GC is a heterogeneous disease and when similar subtypes of gastric cancer are compared, these differences disappear. This study suggests more similarities than previously hypothesized between US and Korean GC patients.

Polymorphisms in ERCC1 and XPF genes and risk of gastric cancer in an eastern Chinese population

BACKGROUND

Inherited functional single nucleotide polymorphisms (SNPs) in DNA repair genes may alter DNA repair capacity and thus contribute to cancer risk.

METHODS

Three ERCC1 functional SNPs (rs2298881C>A, rs3212986C>A and rs11615G>A) and two XPF/ERCC4 functional SNPs (rs2276466C>G and rs6498486A>C) were genotyped for 1125 gastric adenocarcinoma cases and 1196 cancer-free controls by Taqman assays. Odds ratios (OR) and 95% confidence intervals (CI) were used to estimate risk associations, and false-positive report probabilities (FPRP) were calculated for assessing significant findings.

RESULTS

ERCC1 rs2298881C and rs11615A variant genotypes were associated with increased gastric cancer risk (adjusted OR=1.33, 95% CI=1.05-1.67 for rs2298881 AC/CC and adjusted OR=1.23, 95% CI=1.05-1.46 for rs11615 AG/AA, compared with their common genotype AA and GG, respectively). Patients with 2-3 ERCC1 risk genotypes had significant increased risk (adjusted OR=1.56, 95% CI=1.27-1.93), compared with those with 0-1 ERCC1 risk genotypes, and this risk was more significantly in subgroups of never drinkers, non-gastric cardia adenocarcinoma (NGCA) and clinical stage I+II. All these risks were not observed for XPF SNPs.

CONCLUSIONS

These findings suggest that functional ERCC1 SNPs may contribute to risk of gastric cancer. Larger and well-designed studies with different ethnic populations are needed to validate our findings.

Iron in relation to gastric cancer in the Alpha-tocopherol, Beta-carotene Cancer Prevention Study

BACKGROUND

Iron is an essential micronutrient that can have carcinogenic effects when at high or low concentrations. Previous studies of iron in relation to gastric cancer have not assessed subtype-specific relationships. We used the prospective Alpha-Tocopherol, Beta-Carotene (ATBC) Cancer Prevention Study to assess whether iron metrics were associated with gastric cardia cancer (GCC) and gastric noncardia cancer (GNCC).

METHODS

We selected 341 incident gastric cancer cases (86 cardia, 172 noncardia, and 83 nonspecified), accrued during 22 years of follow-up, and 341 individually matched controls. We measured prediagnostic serum iron, ferritin, unsaturated iron binding capacity, and C-reactive protein. Total iron-binding capacity (TIBC) and transferrin saturation were estimated from these metrics. Dietary iron exposures were estimated from a food frequency questionnaire. Multivariable logistic regression was used for analysis.

RESULTS

Serum iron metrics were not associated with GCC, except for a potential "n"-shaped relationship with TIBC (global P = 0.038). GNCC was inversely associated with serum ferritin (global P = 0.024), serum iron (global P = 0.060) and, possibly, transferrin saturation. TIBC appeared to share a "u"-shaped relationship with GNCC (global P = 0.033). Dietary iron exposures were not associated with either subsite. Adjustment for Helicobacter pylori and gastric atrophy had little effect on observed associations.

CONCLUSIONS

We found little evidence for the involvement of iron exposure in the pathogenesis of GCC. GNCC was associated with an iron profile similar to that of iron deficiency.

IMPACT

Our findings indicate that inverse associations between iron metrics and gastric cancer are driven by associations with GNCC. Further elucidation of potential mechanisms is warranted.

Higher prevalence of obesity in gastric cardia adenocarcinoma compared to gastric non-cardia adenocarcinoma

BACKGROUND AND AIMS

Obesity is one of the main risk factors for gastric cardia adenocarcinoma (GCA) in the West. Also, recent studies have suggested that GCA is distinct from distal stomach tumor, with differing risk factors, tumor characteristics, and biological behavior. The objective of our research was to evaluate the relationship between obesity and GCA compared to non-cardia adenocarcinoma.

MATERIALS AND METHODS

A total of 298 patients who were diagnosed with gastric adenocarcinoma and underwent surgery at Seoul National University Bundang Hospital were evaluated. Ninety-one cases were GCA, and 207 cases were non-cardiac adenocarcinoma. Obesity was estimated by body mass index (BMI, kg/m(2)). The degree of obesity was determined by using BMI <18.5, 18.5-23.9, 24-27.9, and ≥ 28 (kg/m(2)) as the cut-off points for underweight, normal weight, overweight, and obese, respectively. Association with obesity was estimated by odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Obesity was more prevalent in patients with GCA at the time of diagnosis for gastric cancer. Among obese persons with a BMI of 28 kg/m(2) or higher, the OR was 3.937 (95% CI, 1.492-10.389; p = 0.006) for GCA compared to non-cardia adenocarcinoma. For overweight individuals, the OR was 2.194 (95% CI, 1.118-4.305; p = 0.022). Multivariate analysis of age, Helicobacter pylori infection, smoking, stage, and BMI with logistic regression was performed. BMI was an independent risk factor for GCA (OR, 1.123; 95% CI, 1.037-1.217; p = 0.004).

CONCLUSION

Obesity was more prevalent in patients with GCA compared to that in patients with gastric non-cardia adenocarcinoma. Also, BMI was an independent risk factor for GCA.

Descriptive epidemiology of gastric adenocarcinoma in the state of Texas by ethnicity: Hispanic versus White non-Hispanic

BACKGROUND

We aimed to evaluate the clinicopathological and demographic characteristics of gastric adenocarcinoma in Hispanics and compare these trends with those found in non-Hispanic Whites in Texas.

METHODS

Records of patients with gastric adenocarcinoma found in the Texas Cancer Registry from 1995 to 2006 were reviewed. Four ethnic-geographic groups were formed: Hispanics residing in El Paso County (a county on the Texas-Mexico border), White non-Hispanics in El Paso County, Hispanics from the remaining counties of Texas combined, and White non-Hispanics from the remaining counties of Texas combined. Adjusted prevalence ratios (PRs) for the outcome of late stage at diagnosis were calculated.

RESULTS

Of 9949 patients, 561 patients were El Paso County residents, of whom 83% were Hispanics. Among the four ethnic-geographic groups, the age-adjusted incidence was the highest in Hispanics in El Paso County (15.5 cases/100000). Tumor pathobiology varied by ethnicity. White non-Hispanics were more likely than Hispanics to have a proximal tumor and less likely to have a poorly differentiated or undifferentiated tumor. In El Paso County, patients in each of the eight age groups under 75 years compared to patients aged ≥85 years were significantly more likely to be at late stage (adjusted PRs 1.44-1.71).

CONCLUSION

The incidence of gastric adenocarcinoma is higher in Hispanics than in Whites in both El Paso County and the remaining portion of Texas. Hispanics have a higher grade of gastric adenocarcinoma. The prevalence of late stage at the time of diagnosis is higher in younger patients than in older patients.

Impact of obesity on perioperative complications and long-term survival of patients with gastric cancer

BACKGROUND

The prevalence of obesity is increasing in the United States. Obesity has been associated with worse surgical outcomes, but its impact on long-term outcomes in gastric cancer is unclear. The aim of this study was to evaluate the effects of being overweight on surgical and long-term outcomes for patients with gastric cancer.

METHODS

Patients who underwent curative intent resection for gastric carcinoma from 1985 to 2007 were identified from a prospectively collected gastric cancer database. Overweight was defined as a body mass index (BMI) of 25 kg/m(2) or higher. Clinical outcomes of overweight and nonoverweight patients were compared.

RESULTS

From the total population of 1,853 patients, 1,125 (60.7%) were overweight. Overweight patients tended to have more proximal tumors and a lower T stage. Accurate complication data were available on a subset of patients from 2000 to 2007. A BMI of ≥25 was associated with increased postoperative complications (47.9 vs. 35.8%, p < 0.001). This was mainly due to an increase in the rate of wound infections (8.9 vs. 4.7%, p = 0.02) and anastomotic leaks (11.8 vs. 5.4%, p = 0.002). Multivariate logistic regression analysis showed that higher BMI, total gastrectomy, and use of neoadjuvant chemotherapy were associated with increased wound infection and anastomotic leak. Overweight patients were less likely to have adequate lymph node staging (73.3 vs. 79.2%, p = 0.047). There was no difference in overall survival or disease-specific survival between the two groups.

CONCLUSIONS

Increased BMI is a predictor of increased postoperative complications, including anastomotic leak, but it is not a predictor of survival in gastric cancer.

The association between obesity factor and esophageal caner

Accumulating epidemiological studies have supported the link between increased body mass index, central obesity and esophageal adenocarcinoma. This association appears stronger than that for other types of obesity-related cancers. Central obesity or visceral fat, more often observed in men, is much more strongly associated with adenocarcinoma than body mass index alone, possibly contributing to the imbalance of disease occurrence between the sexes. Potential mechanisms underlying the association between obesity and esophageal adenocarcinoma have been recently identified, including the insulin-like growth factor pathway, adipokines and sex hormone disturbances. These findings are summarized in this review; however, more research is warranted before these mechanisms are conclusively established.

A meta-analysis of body mass index and esophageal and gastric cardia adenocarcinoma

BACKGROUND

The incidence rates of esophageal and gastric cardia adenocarcinoma (EGCA) have increased over recent years in several countries, and overweight/obesity has been suggested to play a major role in these trends. In fact, higher body mass index (BMI) has been positively associated with EGCA in several studies.

MATERIAL AND METHODS

We conducted a meta-analysis of case-control and cohort studies on the BMI and EGCA updated to March 2011. We estimated overall relative risks (RRs) and 95% confidence intervals (CI) for BMI between 25 and 30 and BMI ≥ 30 kg/m(2), when compared with normo-weight subjects, using random-effects models.

RESULTS

We identified 22 studies, including almost 8000 EGCA cases. The overall RR was 1.71 (95% CI 1.50-1.96) for BMI between 25 and 30, and was 2.34 (95% CI 1.95-2.81) for BMI ≥ 30 kg/m(2). The continuous RR for an increment of 5 kg/m(2) of BMI was 1.11 (95% CI 1.09-1.14). The association was stronger for esophageal adenocarcinoma (RR for BMI ≥ 30 kg/m(2) = 2.73, 95% CI 2.16-3.46) than for gastric cardia adenocarcinoma (RR for BMI ≥ 30 kg/m(2) = 1.93, 95% CI 1.52-2.45). No substantial differences emerged across strata of sex and geographic areas.

CONCLUSION

Overweight and obesity are strongly related to EGCA, particularly to espophageal adenocarcinoma.

Comparative genomic analysis of esophageal adenocarcinoma and squamous cell carcinoma

Esophageal cancer ranks sixth in cancer death. To explore its genetic origins, we conducted exomic sequencing on 11 esophageal adenocarcinomas (EAC) and 12 esophageal squamous cell carcinomas (ESCC) from the United States. Interestingly, inactivating mutations of NOTCH1 were identified in 21% of ESCCs but not in EACs. There was a substantial disparity in the spectrum of mutations, with more indels in ESCCs, A:T>C:G transversions in EACs, and C:G>G:C transversions in ESCCs (P < 0.0001). Notably, NOTCH1 mutations were more frequent in North American ESCCs (11 of 53 cases) than in ESCCs from China (1 of 48 cases). A parallel analysis found that most mutations in EACs were already present in matched Barrett esophagus. These discoveries highlight key genetic differences between EACs and ESCCs and between American and Chinese ESCCs, and suggest that NOTCH1 is a tumor suppressor gene in the esophagus. Finally, we provide a genetic basis for the evolution of EACs from Barrett esophagus.

Polymorphisms in the XPG gene and risk of gastric cancer in Chinese populations

DNA repair genes play an important role in maintaining stability and integrity of genomic DNA. Polymorphisms in nucleotide excision repair genes may cause variations in DNA repair capacity phenotype and thus contribute to cancer risk. In this case-control study of 1,125 gastric cancer cases and 1,196 cancer-free controls, we investigated the association between three functional single nucleotide polymorphisms (SNPs, rs2296147T > C, rs2094258C > T and rs873601G > A) in the xeroderma pigmentosum group G (XPG) gene and gastric cancer risk. We used the Taqman assays to genotype these three SNPs and logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that only the rs873601A variant genotypes were associated with a significant higher risk for gastric adenocarcinoma (adjusted OR = 1.30, 95% CI = 1.03-1.64 for AA vs. GG and adjusted OR = 1.23, 95% CI = 1.01-1.49 for AA vs. GG/AG). Stratification analysis indicated that this risk was more pronounced in subgroups of older age (>59 years), males, ever-smokers, and patients with NGCA. All these were not found for the other two SNPs (rs2296147T > C and rs2094258C > T). We then performed expression analysis using gastric cancer adjacent normal tissues from 141 patients and found that the A variant allele was associated with non-significantly reduced expression of XPG mRNA (P(trend) = 0.107). Further analysis using mRNA expression data from the HapMap suggested that the A allele was associated with significantly reduced expression of XPG mRNA in normal cell lines for 45 Chinese (P(trend) = 0.003) as well as for 261 subjects with different ethnicities (P(trend) = 0.001). These support the hypothesis that functional XPG variants may contribute to the risk of gastric cancer. Larger studies with different ethnic populations are warranted to validate our findings.

Body mass index and survival in esophageal adenocarcinoma treated with chemoradiotherapy followed by esophagectomy

BACKGROUND

Body mass index (BMI) has been linked with inferior outcomes in gastrointestinal malignancies. The purpose of this study is to evaluate the effect of BMI on survival in patients with esophageal adenocarcinoma.

METHODS

Medical records were analyzed for patients who underwent esophagectomy after neoadjuvant chemoradiotherapy (nCRT) for adenocarcinoma from 2000 to the present. Patients were grouped into BMI ≤ 25, >25-30, >30-35, and BMI >35. Overall survival (OS) and disease-free survival (DFS) were analyzed using the Kaplan-Meier method. Multivariate analysis (MVA) was performed using Cox proportional hazard regression model.

RESULTS

We identified 303 patients for the analysis. The only difference in patient characteristics between groups was gender. We found no difference in OS and DFS associated with BMI (p=0.3297 for OS; p=0.5950 for DFS). There were no differences in postoperative complications or mortality between BMI groups. MVA revealed that higher stage and less than a complete response to nCRT were prognostic for worse OS and DFS, while age, gender, type of surgery, year of diagnosis, and BMI were not prognostic.

CONCLUSIONS

BMI was neither associated with surgical complications nor survival in patients with esophageal adenocarcinoma treated with nCRT. BMI should not be considered a contraindication to surgical resection after nCRT.

The importance of exposure rate on odds ratios by cigarette smoking and alcohol consumption for esophageal adenocarcinoma and squamous cell carcinoma in the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium

BACKGROUND

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.

METHODS

The authors pooled data from 12 case-control studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON), including 1242 (EAC), 1263 (EGJA) and 954 (ESCC) cases and 7053 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.

RESULTS

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).

CONCLUSIONS

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.

Comparison of gastro-oesophageal junction carcinomas in Chinese versus American patients

AIMS

To compare the clinical and pathological features of gastro-oesophageal junction (GEJ) carcinomas in Chinese and American patients.

METHODS AND RESULTS

Eighty consecutive patients with a GEJ carcinoma (43 from mainland China, and 37 from the USA) were evaluated for association with Barrett oesophagus (BO), chronic Helicobacter pylori gastritis, intestinal metaplasia, and outcome. GEJ carcinomas were defined as tumours that were located within 20 mm of, and crossed, the GEJ. Overall, GEJ carcinomas from Chinese patients revealed significantly more frequent location in the proximal stomach, higher pathological stage, larger size, younger patient age, and association with chronic H. pylori gastritis. In contrast, GEJ cancers from American patients showed a strong association with distal oesophageal location, BO, and associated intestinal metaplasia and dysplasia. Pathologically, GEJ carcinomas from American patients were predominantly adenocarcinomas, whereas Chinese patients showed a higher proportion of mucinous, adenosquamous, acinar or neuroendocrine tumours. Overall, 3- and 5-year survival rates were statistically similar between both patient groups, but upon multivariate analysis, Chinese patients showed statistically better survival rates for stage III tumours.

CONCLUSIONS

Most GEJ carcinomas in patients from China represent proximal gastric cancers associated with chronic H. pylori gastritis, and BO-associated carcinomas are rare among this patient population.

Prognostic impact of body mass index stratified by smoking status in patients with esophageal adenocarcinoma

PURPOSE

Given that smoking affects body mass index (BMI) and survival, stratification by smoking status may be required to determine the true prognostic impact of BMI. Although obesity increases risk for developing esophageal adenocarcinoma (EAC), the prognostic influence of obesity and its potential modification by smoking status is unknown in this disease.

PATIENTS AND METHODS

All patients (N = 778) underwent potentially curative esophagectomy. BMI was calculated using measured height and weight at surgery and categorized as obese (≥ 30 kg/m(2)), overweight (25 to 29.9 kg/m(2)), or normal (18.5 to 24.9 kg/m(2)). Cigarette smoking was categorized as never or ever. The association of BMI with disease-specific survival (DSS), disease-free survival (DFS), and overall survival (OS) was determined by Cox regression.

RESULTS

Excess BMI was significantly associated with DSS in a manner that differed substantially by smoking status (P for interaction = .023). Among never smokers, obesity was significantly associated with adverse DSS (hazard ratio [HR] = 2.11; 95% CI, 1.31 to 3.43; P = .002), DFS (HR = 2.03; 95% CI, 1.30 to 3.18; P = .002), and OS (HR = 1.97; 95% CI, 1.24 to 3.14; P = .004), as compared with normal weight, after adjusting for covariates. By contrast, among ever smokers, obesity was not prognostic, and overweight status was significantly associated with favorable survival in univariate, but not multivariate, analysis.

CONCLUSION

Obesity among never smokers was independently associated with two-fold worsening of DSS, DFS, and OS after surgery for EAC, after adjusting for known prognostic factors. These data, in one of the largest reported resected EAC cohorts, are the first to show an adverse prognostic impact of obesity in EAC.

Barrett's esophagus: prevalence-incidence and etiology-origins

Although the prevalence of Barrett's esophagus (BE) is rising no data exist for racial minorities on prevalence in the general population. Minorities have a lower prevalence than Caucasians, and yet age, smoking, abdominal obesity, and Helicobacter pylori are all risk factors. Metabolic changes induced by adipocytokines and the apparently strong association between obesity, central adiposity, and BE may lead to reconsideration of some aspects of the natural history of BE. There is lack of experimental evidence on acid sensitivity and BE, which is hyposensitive compared to esophageal reflux disease. Reactive nitrogen and oxygen species lead to impaired expression of tumor suppressor genes, which can lead to cancer development; thus, antioxidants may be protective. Gastroesophageal reflux disease may be considered an immune-mediated disease starting at the submucosal layer; the cytokine profile of the mucosal immune response may explain the different outcome of gastroesophageal reflux.

Epidemiology of noncardia gastric adenocarcinoma in the United States

OBJECTIVES

Adenocarcinomas of the cardia (International Classification of Diseases (ICD)-9 code 151.0) and stomach (ICD-9 codes 151.1-151.9) are frequently grouped together in epidemiologic statistics, but are clearly distinct diseases. The objective of this study was to describe the current epidemiology of noncardia gastric cancer (noncardia gastric adenocarcinoma (NCGA)) in the United States.

METHODS

Rates of NCGA in the United States from 1997 to 2008 were analyzed in three national databases: the Surveillance, Epidemiology, and End Results registry was used for incidence, the Healthcare Costs and Utilization Project for hospitalizations, and the Compressed Mortality File for mortality. Population-based rates were calculated and age-adjusted to the US 2000 population using direct standardization. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated and adjusted for confounders with the Mantel-Haenszel method.

RESULTS

Annually, NCGA was associated with 18,873 incident cases, 17,284 hospitalizations for principal discharge diagnoses, 31,354 hospitalizations for all-listed diagnoses, and 11,562 deaths. Incidence was greater in men (OR=1.56, CI=1.53-1.59) and non-White races (OR=2.38, 2.33-2.43). Hospitalization was more common in men (1.82, 1.81-1.83) and non-White races (2.13, 2.10-2.15). Mortality was more common in men (1.83, 1.81-1.86) and non-White races (2.23, 2.20-2.26). NCGA rates showed a marked age-dependent rise (P<0.001). Hospitalization and mortality were greatest in the Northeast region of the United States (P<0.001).

CONCLUSIONS

Epidemiologic patterns of NCGA were congruent in three national databases. Older age, male gender, non-White race, and residence in the Northeast region were associated with increased risk. These patterns may reflect the underlying variations in Helicobacter pylori, lifestyle, and environmental exposures.

Spatial autocorrelation calculations of the nine malignant neoplasms in Taiwan in 2005-2009: a gender comparison study

Spatial analytical techniques and models are often used in epidemiology to identify spatial anomalies (hotspots) in disease regions. These analytical approaches can be used to identify not only the location of such hotspots, but also their spatial patterns. We used spatial autocorrelation methodologies, including Global Moran's I and Local Getis-Ord statistics, to describe and map spatial clusters and areas in which nine malignant neoplasms are situated in Taiwan. In addition, we used a logistic regression model to test the characteristics of similarity and dissimilarity between males and females and to formulate the common spatial risk. The mean found by local spatial autocorrelation analysis was used to identify spatial cluster patterns. We found a significant relationship between the leading malignant neoplasms and well-documented spatial risk factors. For instance, in Taiwan, the geographic distribution of clusters where oral cavity cancer in males is prevalent was closely correspond to the locations in central Taiwan with serious metal pollution. In females, clusters of oral cavity cancer were closely related with aboriginal townships in eastern Taiwan, where cigarette smoking, alcohol drinking, and betel nut chewing are commonplace. The difference between males and females in the spatial distributions was stark. Furthermore, areas with a high morbidity of gastric cancer were clustered in aboriginal townships where the occurrence of Helicobacter pylori is frequent. Our results revealed a similarity between both males and females in spatial pattern. Cluster mapping clarified the spatial aspects of both internal and external correlations for the nine malignant neoplasms. In addition, using a method of logistic regression also enabled us to find differentiation between gender-specific spatial patterns.

Genome wide single cell analysis of chemotherapy resistant metastatic cells in a case of gastroesophageal adenocarcinoma

Background

Metastatic progression due to development or enrichment of therapy-resistant tumor cells is eventually lethal. Molecular characterization of such chemotherapy resistant tumor cell clones may identify markers responsible for malignant progression and potential targets for new treatment. Here, in a case of stage IV adenocarcinoma of the gastroesophageal junction, we report the successful genome wide analysis using array comparative genomic hybridization (CGH) of DNA from only fourteen tumor cells using a bead-based single cell selection method from a bone metastasis progressing during chemotherapy.

Case presentation

In a case of metastatic adenocarcinoma of the gastroesophageal junction, the progression of bone metastasis was observed during a chemotherapy regimen of epirubicin, oxaliplatin and capecitabine, whereas lung-, liver and lymph node metastases as well as the primary tumor were regressing. A bone marrow aspirate sampled at the site of progressing metastasis in the right iliac bone was performed, and single cell molecular analysis using array-CGH of Epithelial Specific Antigen (ESA)-positive metastatic cells, and revealed two distinct regions of amplification, 12p12.1 and 17q12-q21.2 amplicons, containing the KRAS (12p) and ERBB2 (HER2/NEU) (17q) oncogenes. Further intrapatient tumor heterogeneity of these highlighted gene copy number changes was analyzed by fluorescence in situ hybridization (FISH) in all available primary and metastatic tumor biopsies, and ErbB2 protein expression was investigated by immunohistochemistry.

ERBB2 was heterogeneously amplified by FISH analysis in the primary tumor, as well as liver and bone metastasis, but homogenously amplified in biopsy specimens from a progressing bone metastasis after three initial cycles of chemotherapy, indicating a possible enrichment of erbB2 positive tumor cells in the progressing bone marrow metastasis during chemotherapy. A similar amplification profile was detected for wild-type KRAS, although more heterogeneously expressed in the bone metastasis progressing on chemotherapy. Correspondingly, the erbB2 protein was found heterogeneously expressed by immunohistochemical staining of the primary tumor of the gastroesophageal junction, while negative in liver and bone metastases, but after three initial cycles of palliative chemotherapy with epirubicin, oxaliplatin and capecetabine, the representative bone metastasis stained strongly positive for erbB2.

Conclusion

Global analysis of genetic aberrations, as illustrated by performing array-CGH analysis on genomic DNA from only a few selected tumor cells of interest sampled from a progressing bone metastasis, can identify relevant therapeutic targets and genetic aberrations involved in malignant progression, thus emphasizing the importance and feasibility of this powerful tool on the road to more personalized cancer therapies in the future.

The impact of obesity on the rise in esophageal adenocarcinoma incidence: estimates from a disease simulation model

BACKGROUND

The United States has experienced an alarming and unexplained increase in the incidence of esophageal adenocarcinoma (EAC) since the 1970s. A concurrent increase in obesity has led some to suggest a relationship between the two trends. We explore the extent of this relationship.

METHODS

Using a previously validated disease simulation model of white males in the United States, we estimated EAC incidence 1973 to 2005 given constant obesity prevalence and low population progression rates consistent with the early 1970s. Introducing only the observed, rising obesity prevalence, we calculated the incremental incidence caused by obesity. We compared these with EAC incidence data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registry to determine obesity's contribution to the rise therein. Incidences were converted to absolute numbers of cases using U.S. population data.

RESULTS

Using constant obesity prevalence, we projected a total of 30,555 EAC cases cumulatively over 1973 to 2005 and 1,151 in 2005 alone. Incorporating the observed obesity trend resulted in 35,767 cumulative EACs and 1,608 in 2005. Estimates derived from SEER data showed 111,223 cumulative and 7,173 cases in 2005. We conclude that the rise in obesity accounted for 6.5% of the increase in EAC cases that occurred from 1973 to 2005 and 7.6% in the year 2005.

CONCLUSION

Using published OR for EAC among obese individuals, we found that only a small percentage of the rise in EAC incidence is attributable to secular trends in obesity.

IMPACT

Other factors, alone and in combination, should be explored as causes of the EAC epidemic.

Gastroesophageal reflux disease symptom severity, proton pump inhibitor use, and esophageal carcinogenesis

HYPOTHESIS

Screening for esophageal adenocarcinoma has focused on identifying Barrett esophagus (BE) in patients with severe, long-standing symptoms of gastroesophageal reflux disease (GERD). Unfortunately, 95% of patients who develop esophageal adenocarcinoma are unaware of the presence of BE before their cancer diagnosis, which means they never had been selected for screening. One possible explanation is that no correlation exists between the severity of GERD symptoms and cancer risk. We hypothesize that severe GERD symptoms are not associated with an increase in the prevalence of BE, dysplasia, or cancer in patients undergoing primary endoscopic screening.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENTS

A total of 769 patients with GERD.

INTERVENTIONS

Primary screening endoscopy performed from November 1, 2004, through June 7, 2007.

MAIN OUTCOMES MEASURES

Symptom severity, proton pump inhibitor therapy, and esophageal adenocarcinogenesis (ie, BE, dysplasia, or cancer).

RESULTS

Endoscopy revealed adenocarcinogenesis in 122 patients. An increasing number of severe GERD symptoms correlated positively with endoscopic findings of esophagitis (odds ratio, 1.05; 95% confidence interval, 1.01-1.09). Conversely, an increasing number of severe GERD symptoms were associated with decreased odds of adenocarcinogenesis (odds ratio, 0.94; 95% confidence interval, 0.89-0.98). Patients taking proton pump inhibitors were 61.3% and 81.5% more likely to have adenocarcinogenesis if they reported no severe typical or atypical GERD symptoms, respectively, compared with patients taking proton pump inhibitors, who reported that all symptoms were severe.

CONCLUSIONS

Medically treated patients with mild or absent GERD symptoms have significantly higher odds of adenocarcinogenesis compared with medically treated patients with severe GERD symptoms. This finding may explain the failure of the current screening paradigm in which the threshold for primary endoscopic examination is based on symptom severity.

Influence of obesity on the risk of esophageal disorders

Obesity is associated with an increased risk of esophageal disorders, including esophageal adenocarcinoma, Barrett esophagus and GERD. For reasons yet unknown, the association between obesity and esophageal adenocarcinoma seems to be stronger than that for other types of obesity-related cancers. Predominantly abdominal or intra-abdominal adiposity (representing visceral fat and other fat within the abdominal cavity), which is more frequently observed in men than in women, is more strongly linked with these esophageal disorders than BMI alone, a finding that might contribute to the striking male predominance of esophageal adenocarcinoma. Research has identified potential mechanisms underlying the strong link between obesity and esophageal conditions. These findings are summarized in this Review, but more research remains to be carried out before these mechanisms are established.

Obesity, metabolic syndrome and esophageal adenocarcinoma: epidemiology, etiology and new targets

BACKGROUND

Rates of distal and junctional adenocarcinomas are increasing in Western countries.

METHODS

Systematic review of epidemiological evidence linking obesity to esophageal adenocarcinoma (EA) was performed for studies published from 2005 to 2010. The current understanding of obesity's role in the etiology and potential dysplastic progression of Barrett's esophagus (BE) to EA is reviewed.

RESULTS

Accumulating epidemiological studies provide evidence of obesity's role as a driving force behind the increasing rates of EA. The simplest construct is that obesity promotes reflux, causing chronic inflammation and BE, predisposing to adenocarcinoma. However, as obesity is positively associated with the prevalence of many cancers, other mechanisms are important. A link may exist between fat distribution patterns and the risk of BE and EA. Altered metabolic profiles in the metabolic syndrome (MetS) may be a key factor in cell cycle/genetic abnormalities that mark the progression of BE towards cancer. Research highlighting a unique role of MetS in the length of BE, and its association with systemic inflammation and insulin resistance is discussed, as well as adipokine receptor expression in both BE and esophageal epithelium, and how MetS and the systemic response impacts on key regulators of inflammation and tumorigenesis. CONCLUSIONS/IMPACT: Obesity is positively associated with EA. The systemic inflammatory state consequent on the altered metabolism of obese patients, and the associated impact of adipocytokines and pro-coagulant factors released by adipocytes in central fat, may underlie obesity's relationship to this cancer. Novel therapeutic agents that may antagonize adipo-cytokines and potentially offer a promising role in cancer therapy are discussed.

Principal component analysis of dietary and lifestyle patterns in relation to risk of subtypes of esophageal and gastric cancer

PURPOSE

To carry out pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers.

METHODS

We evaluated risk factors for esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and other gastric cancers (OGA) using data from a population-based case-control study conducted in Connecticut, New Jersey, and western Washington state. Dietary/lifestyle patterns were created using principal component analysis (PCA). Impact of the resultant scores on cancer risk was estimated through logistic regression.

RESULTS

PCA identified six patterns: meat/nitrite, fruit/vegetable, smoking/alcohol, legume/meat alternate, GERD/BMI, and fish/vitamin C. Risk of each cancer under study increased with rising meat/nitrite score. Risk of EA increased with increasing GERD/BMI score, and risk of ESCC rose with increasing smoking/alcohol score and decreasing gastroesophageal reflux disease (GERD)/body mass index (BMI) score. Fruit/vegetable scores were inversely associated with EA, ESCC, and GCA.

CONCLUSIONS

PCA may provide a useful approach for summarizing extensive dietary/lifestyle data into fewer interpretable combinations that discriminate between cancer cases and controls. The analyses suggest that meat/nitrite intake is associated with elevated risk of each cancer under study, whereas fruit/vegetable intake reduces risk of EA, ESCC, and GCA. GERD/obesity were confirmed as risk factors for EA and smoking/alcohol as risk factors for ESCC.

Prospective study of self-reported diabetes and risk of upper gastrointestinal cancers

BACKGROUND

Although gastric noncardia adenocarcinoma (GNCA) incidence rates in the United States 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.

METHODS

We prospectively examined the association between diabetes and upper gastrointestinal (UGI) cancers in a cohort of 469,448 people in the United States, ages 50 to 71 at baseline. Cox proportional hazards regression was used to estimate the HR and 95% CI for diabetes and UGI cancers, controlling for multiple potential confounders, including body mass index (BMI).

RESULTS

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 (P(interaction) = 0.83). The significant association was unchanged when restricting to only overweight subjects (BMI 25 to ≤30), HR (95% CI) = 1.83 (1.18-2.85).

CONCLUSIONS

We found a significant association between self-reported diabetes and increased risk of GCA.

IMPACT

Our results suggest that the metabolic and hormonal changes related to diabetes may play a role in the etiology of GCA independently from BMI.

MET expression and amplification in patients with localized gastric cancer

BACKGROUND

MET, the receptor for hepatocyte growth factor, has been proposed as a therapeutic target in gastric cancer. This study assessed the incidence of MET expression and gene amplification in tumors of Western patients with gastric cancer.

METHODS

Tumor specimens from patients enrolled on a preoperative chemotherapy study (NCI 5700) were examined for the presence of MET gene amplification by FISH, MET mRNA expression by quantitative PCR, MET overexpression by immunohistochemistry (IHC), and for evidence of MET pathway activation by phospho-MET (p-MET) IHC.

RESULTS

Although high levels of MET protein and mRNA were commonly encountered (in 63% and 50% of resected tumor specimens, respectively), none of these tumors had MET gene amplification by FISH, and only 6.6% had evidence of MET tyrosine kinase activity by p-MET IHC.

CONCLUSIONS

In this cohort of patients with localized gastric cancer, the presence of high MET protein and RNA expression does not correlate with MET gene amplification or pathway activation, as evidenced by the absence of amplification by FISH and negative p-MET IHC analysis.

IMPACT

This article shows a lack of MET amplification and pathway activation in a cohort of 38 patients with localized gastric cancer, suggesting that MET-driven gastric cancers are relatively rare in Western patients.

Current status of Barrett's esophagus research in Asia

In Western countries, the epidemiology of esophageal cancer has changed considerably over the past decades with a rise in the ratio of adenocarcinoma to squamous cell carcinoma. Although the prevalence of gastroesophageal reflux is increasing in Asia, the prevalences of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) have remained low in most Asian countries. The Asian Barrett's Consortium recently conducted a review of published studies on BE from Asia to assess the current status of BE research in Asia, and to recommend potential areas for future BE research in the region. Differences in study design, enrolled population, and endoscopic biopsy protocols used have led to substantial variability in the reported BE prevalence (0.06% to 19.9%) across Asia. In particular, some Japanese studies used diagnostic criteria that differed considerably from what was used in most Asian studies. As in Western countries, increased age, male sex, tobacco smoking, reflux symptoms, and erosive esophagitis have been found to be risk factors for BE in several case-control studies from Asia. The Prague C and M criteria, developed to provide better interobserver reliability in diagnosis and grading of BE, are currently under extensive evaluation in the Asian population. There is a need for standardized protocols for endoscopic and histopathologic diagnosis before initiating collaborative projects to identify etiologic determinants of BE and its ensuing malignant transformation. At present, data regarding the management and long-term outcome of BE are extremely limited in Asia. More studies of BE in this geographic area are warranted.

High intake of folate from food sources is associated with reduced risk of esophageal cancer in an Australian population

Folate plays a key role in DNA synthesis and methylation. Limited evidence suggests high intake may reduce risks of esophageal cancer overall; however, associations with esophageal cancer subtypes and Barrett's esophagus (BE), a precancerous lesion, remain unexplored. We evaluated the relation between intake of folate, B vitamins, and methyl-group donors (methionine, choline, betaine) from foods and supplements, polymorphisms in key folate-metabolizing genes, and risk of BE, esophageal adenocarcinoma (EAC), and esophageal squamous cell carcinoma (ESCC) in 2 population-based case-control studies in Australia. BE patients without (n = 266) or with (n = 101) dysplasia were compared with population controls (n = 577); similarly, EAC (n = 636) or ESCC (n = 245) patients were compared with population controls (n = 1507) using multivariable adjusted logistic regression. Increasing intake of folate from foods was associated with reduced EAC risk (P-trend = 0.01) and mitigated the increased risks of ESCC associated with smoking and alcohol consumption. In contrast, high intake of folic acid from supplements was associated with a significantly elevated risk of BE with dysplasia. High intakes of riboflavin and methionine from food were associated with increased EAC risk, whereas increasing betaine intake was associated with reduced risks of BE without (P-trend = 0.004) or with dysplasia (P-trend = 0.02). Supplemental thiamin, riboflavin, niacin, and vitamin B-12 were associated with increased EAC risk. There were no consistent associations between genetic polymorphisms studied and BE or EAC risk. High intake of folate-containing foods may reduce risk of EAC, but our data raise the possibility that folic acid supplementation may increase risks of BE with dysplasia and EAC.

Role of obesity-associated dysfunctional adipose tissue in cancer: a molecular nutrition approach

Obesity is a complex disease caused by the interaction of a myriad of genetic, dietary, lifestyle and environmental factors, which favors a chronic positive energy balance, leading to increased body fat mass. There is emerging evidence of a strong association between obesity and an increased risk of cancer. However, the mechanisms linking both diseases are not fully understood. Here, we analyze the current knowledge about the potential contribution that expanding adipose tissue in obesity could make to the development of cancer via dysregulated secretion of pro-inflammatory cytokines, chemokines and adipokines such as TNF-α, IL-6, leptin, adiponectin, visfatin and PAI-1. Dietary factors play an important role in the risk of suffering obesity and cancer. The identification of bioactive dietary factors or substances that affect some of the components of energy balance to prevent/reduce weight gain as well as cancer is a promising avenue of research. This article reviews the beneficial effects of some bioactive food molecules (n-3 PUFA, CLA, resveratrol and lipoic acid) in energy metabolism and cancer, focusing on the molecular mechanisms involved, which may provide new therapeutic targets in obesity and cancer.

Symptoms, investigations and management of patients with cancer of the oesophagus and gastro-oesophageal junction in Australia

OBJECTIVE

To document presenting symptoms, investigations and management for Australian patients with oesophageal adenocarcinoma (OAC), gastro-oesophageal junction adenocarcinoma (GOJAC) and oesophageal squamous cell carcinoma (OSCC).

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional study of a population-based sample of 1100 Australian patients aged 18-79 years with histologically confirmed oesophageal cancer diagnosed in 2002-2005, using data from cancer registries and treatment centres, supplemented with clinical information collected through medical record review in 2006-2007 and mortality information collected in 2008.

MAIN OUTCOME MEASURES

Prevalence of primary symptoms, and staging investigations and treatment modalities used.

RESULTS

The primary presenting symptom was dysphagia, which was self-reported by 41%, 39% and 48% of patients with OAC, GOJAC and OSCC, respectively. Less common symptoms were reflux, chest pain, bleeding and weight loss. All patients underwent endoscopy, most had a staging computed tomography scan (OAC 93%, GOJAC 95% and OSCC 93%), and about half had positron emission tomography scans (OAC 51%, GOJAC 44% and OSCC 42%). Pretreatment tumour stage was reported in 25% of records, and could be derived from results of investigations in a further 23%, but the remaining half lacked sufficient information to ascribe a pretreatment stage. Curative treatments were attempted for 60% of OAC, 88% of GOJAC and 65% of OSCC patients. Surgery was performed on 52% of OAC, 83% of GOJAC and 41% of OSCC patients. About two-thirds of surgical patients received additional therapies.

CONCLUSIONS

With anticipated increases in oesophageal cancer incidence, the resources required to diagnose and manage patients with oesphageal cancer are also likely to rise. Our data provide a baseline from which to plan for the future care of patients with cancers of the oesophagus.

Meta-analysis: the association of oesophageal adenocarcinoma with symptoms of gastro-oesophageal reflux

BACKGROUND

Endoscopic screening has been proposed for patients with symptoms of gastro-oesophageal reflux disease (GERD) in the hope of reducing mortality from oesophageal adenocarcinoma. Assessing the net benefits of such a strategy requires a precise understanding of the cancer risk in the screened population.

AIM

To estimate precisely the association between symptoms of GERD and oesophageal adenocarcinoma.

METHODS

Systematic review and meta-analysis of population-based studies with strict ascertainment of exposure and outcomes.

RESULTS

Five eligible studies were identified. At least weekly symptoms of GERD increased the odds of oesophageal adenocarcinoma fivefold (odds ratio = 4.92; 95% confidence interval = 3.90, 6.22), and daily symptoms increased the odds sevenfold (random effects summary odds ratio = 7.40, 95% confidence interval = 4.94, 11.1), each compared with individuals without symptoms or less frequent symptoms. Duration of symptoms was also associated with oesophageal adenocarcinoma, but with very heterogeneous results, and unclear thresholds.

CONCLUSIONS

Frequent GERD symptoms are strongly associated with oesophageal adenocarcinoma. These results should be useful in developing epidemiological models of the development of oesophageal adenocarcinoma, and in models of interventions aimed at reducing mortality from this cancer.