Xiao-Ting Wu

Overweight, obesity and gastric cancer risk: Results from a meta-analysis of cohort studies

The relationship between excess body weight and gastric cancer risk has not been well studied to date. We therefore carried out a systematic review and meta-analysis of published cohort studies to evaluate the association between excess body weight and gastric cancer risk. An electronic search of the MEDLINE, PubMed, EMBASE and Academic Search Premier (EBSCO) databases, which contain articles published from 1950 onwards, was conducted in order to select studies for this meta-analysis. Ten studies with a total number of 9492 gastric cancer cases and a studied population of 3,097,794 were identified. Overall, excess body weight [body mass index (BMI)25] was associated with an increased risk of gastric cancer [odds ratio (OR)=1.22; 95% confidence intervals (CIs)=1.06-1.41]. Specifically, a stratified analysis showed that excess body weight was associated with an increased risk of cardia gastric cancer [overweight and obese (BMI 25), OR=1.55, 95% CIs=1.31-1.84] and gastric cancer among non-Asians (overweight and obese, OR=1.24, 95% CIs=1.14-1.36); however, the stratified analysis also showed that there was no statistically significant link between excess body weight and gastric cancer in the following subgroups: males (overweight and obese, OR=1.22, 95% CIs=0.96-1.55), females (overweight and obese, OR=1.13, 95% CIs=0.65-1.94), non-cardia gastric cancer (overweight and obese, OR=1.18, 95% CIs=0.96-1.45) and Asians (overweight and obese, OR=1.17, 95% CIs=0.88-1.56). The combined results of this meta-analysis, however, do indicate that overweight and obesity are associated with an increased risk of gastric cancer. The strength of the association also increases with increasing BMI.

P53 codon 72 polymorphism and gastric cancer: A meta-analysis of the literature

Studies investigating the association between p53 codon 72 polymorphism and gastric cancer risk report conflicting results. The objective of this study was to quantitatively summarize the evidence for such a relationship. Two investigators independently searched the Medline and Embase databases. This meta‐analysis included 12 case‐control studies, which included 1,665 gastric cancer cases and 2,358 controls. The combined results based on all studies showed that there was no significant difference in genotype distribution [Arg/Arg odds ratio (OR) = 0.96, 95% confidence interval (CI) = 0.79, 1.16; Pro/Pro (OR = 1.21, 95% CI = 0.92, 1.58); Pro/Arg (OR = 0.95, 95% CI = 0.79, 1.14)] between gastric cancer and noncancer patients. When stratifying for race, results were similar except that patients with gastric cancer had a significantly lower frequency of Arg/Arg (OR = 0.84, 95% CI = 0.72, 0.99) than noncancer patients among Asians. Stratified the various studies by the location, stage, Laurens classification, and histological differentiation of gastric cancer, we found that (i) patients with cardia gastric cancer had a significantly higher frequency of Pro/Pro (OR = 3.20, 95% CI = 1.46,7.01) than those with noncardia gastric cancer among Asians; (ii) patients with advanced (stage III/IV) gastric cancer had a significantly higher frequency of Arg/Arg (OR = 1.48, 95% CI = 1.01, 2.16) than those with early (stage I/II) gastric cancer among Asians; (iii) patients with poor differentiation had a significantly lower frequency of Pro/Pro (OR = 0.13, 95% CI = 0.03, 0.64) than those with well differentiation among Caucasians. This meta‐analysis suggests that the p53 codon 72 polymorphism may be associated with gastric cancer among Asians, and that difference in genotype distribution may be associated with the location, stage, and histological differentiation of gastric cancer.

Safety and Efficacy of Fish Oil–Enriched Parenteral Nutrition Regimen on Postoperative Patients Undergoing Major Abdominal Surgery A Meta-Analysis of Randomized Controlled Trials

BACKGROUND To evaluate the safety and efficacy of a fish oil-enriched parenteral nutrition regimen in patients undergoing major abdominal surgery, a meta-analysis of randomized controlled trials was conducted. METHODS An electronic search of PubMed, MEDLINE, EMBASE, Academic Search Premier, and China National Knowledge Infrastructure databases was performed in March 2009. RevMan 5.0 was used for statistical analysis. RESULTS The combined analysis showed that a fish oil-enriched parenteral nutrition regimen had a positive treatment effect on length of hospital stay (weighed mean difference = -2.98, P < .001), length of intensive care unit stay, postoperative infection rate (odds ratio = 0.56, P = .04), and serum levels of aspartate aminotransferase, alanine aminotransferase, and alpha-tocopherol on postoperative day 6 in these patients. The regimen increased the plasma levels of eicosapentaenoic acid (standardized mean difference = 3.11, P < .001) and docosahexaenoic acid and upregulated the leukotriene B(5) production in leukocytes on postoperative day 6. No significant differences were found between the 2 groups in postoperative mortality; incidence of postoperative cardiac complications; serum levels of bilirubin, triglyceride, or arachidonic acid; or the liberation of leukotriene B(4). No serious adverse events related to fish oil treatment were reported. CONCLUSIONS Based on the meta-analysis, fish oil-supplemented parenteral nutrition was safe, improved clinical outcomes, and altered the fatty acid pattern as well as leukotriene synthesis. More laboratory parameters should be considered in future meta-analyses.

Interleukin-10 -1082 promoter polymorphism associated with gastric cancer among Asians

Studies investigating the association between interleukin-10 (IL-10) -1082 promoter polymorphism and gastric cancer risk report conflicting results. The objective of this study was to quantitatively summarise the evidence for such a relationship. Two investigators independently searched the Medline and Embase databases. This meta-analysis included 13 case-control studies, which included 2227 gastric cancer cases and 3538 controls. The combined results based on all studies showed that there was no significant difference in genotype distribution [AA odds ratio (OR)=0.92, 95% confidence interval (CI)=0.73, 1.14; AG (OR=1.09, 95% CI=0.87, 1.36); GG (OR=1.03, 95% CI=0.85, 1.25)] between gastric cancer and noncancer patients. When stratifying for race, results were similar except that patients with gastric cancer had a significantly lower frequency of AA (OR=0.71, 95% CI=0.52, 0.97) and higher frequency AG (OR=1.53, 95% CI=1.15, 2.03) than noncancer patients among Asians. When stratifying by the location of gastric cancer, we found that patients with cardia gastric cancer had a significantly lower frequency of AA (OR=0.53, 95% CI=0.34, 0.83) and higher frequency AG (OR=1.50, 95% CI=1.06, 2.11) than those with noncardia gastric cancer among Caucasians. When stratifying by the Laurens classification of gastric cancer, we observed no statistically significant differences in genotype distribution. This meta-analysis suggests that the IL-10 -1082 promoter polymorphism may be associated with gastric cancer among Asians, and that differences in genotype distribution may be associated with the location of gastric cancer.

Interleukin-8 -251 A/T gene polymorphism and gastric cancer susceptibility: a meta-analysis of epidemiological studies.

Previous studies suggested the relationship between interleukin (IL)-8 -251 A/T gene polymorphism and risk of gastric cancer (GC). However, the currently available results were not consistent. The present study aimed to quantitatively analyse this association using a meta-analysis. Published literature from PubMed, EMBASE and CNKI (China Knowledge Resource Integrated Database) were retrieved. Twelve case-control studies with 3012 cases of GC and 3893 controls were included. Overall, IL-8 -251 A/T polymorphism was not associated with the risk of GC. However, when stratified for ethnicity/country, the results showed that A allele carriers had an increased risk of GC while T allele carriers had a decreased risk of GC in Korean people. When stratified for Helicobacter pylori infection, the results showed that A allele carriers with H. pylori infection had an increased risk of GC while T allele carriers with or without H. pylori infection had a decreased risk of GC. When stratified for tumor location and histological type (Laurens classification), A allele carriers had an increased risk of intestinal- and diffuse-type of GC and non-cardia cancer, while T allele carriers had a decreased risk of intestinal- and diffuse-type of GC and non-cardia cancer. These results suggest that overall IL-8 -251 A/T gene polymorphism is not associated with the risk of GC and the association may be varied according to histological type, tumor location, H. pylori infection and ethnicity/country. More well-designed studies based on larger population are needed to confirm our results and further evaluate the association between IL-8 -251 A/T gene polymorphism and gastric cancer.

Is dietary fat associated with the risk of colorectal cancer? A meta-analysis of 13 prospective cohort studies

BackgroundThe results of animal studies suggest there is a significant role for dietary fat in the development of colorectal cancer (CRC). However, inconsistent results have been reported by epidemiological studies.Aim of studyTo evaluate the association between total dietary fat and risk of colorectal cancer development using a meta-analysis based on prospective cohort studies.MethodsPublished literature was retrieved from Medline, Embase and CNKI (China Knowledge Resource Integrated Database) databases updated to 1st May, 2009. Overall, thirteen prospective cohort studies with 3,635 cases and 459,910 participants were included.ResultsThe combined relative risk (RR) [95% confidence interval (95%CI)] for the risk of CRC was 0.99 (0.89,1.09) when the highest level of total dietary fat was versus (vs.) the lowest level. Stratified analyses according to gender, ethnicity, country and age showed that the highest level of total dietary fat did not increase the risk of CRC [RR (95%CI): 0.89 (0.77,1.03) for males; 1.09 (0.94,1.26) for females; 1.08 (0.94,1.25) for Caucasians; 0.90 (0.77,1.04) for Asians; 1.13 (0.94,1.36) for Americans; 0.92 (0.81,1.04) for individuals older than 40]. Besides those, the highest level of total fat diet also did not increase the risk of neither colon cancer [RR (95%CI): 0.96 (0.82,1.13)] nor rectal cancer [RR (95%CI):1.07 (0.63,1.82)]. Furthermore, neither animal fat nor plant fat were associated with the risk of CRC [RR (95%CI): 1.05 (0.91–1.22) for animal fat and 0.96 (0.82–1.11) for plant fat].ConclusionsThis meta-analysis suggests that dietary fat may not be associated with the increased risk of CRC. More well-designed studies with larger population performed among Asians are needed to further evaluate the associations. In addition, probable bias caused by measurement error should be noticed in this meta-analysis, and measurement error needs to be adjusted in the future studies.

Vascular endothelial growth factor (VEGF) gene polymorphisms and gastric cancer risk in a Chinese Han population

The association between vascular endothelial growth factor (VEGF) gene polymorphisms and gastric cancer risk is still controversial and ambiguous. The objective of this study was to investigate the association between VEGF gene polymorphisms and gastric cancer risk in Chinese Han patients. We extracted the peripheral blood samples in 150 patients with gastric cancer and 150 controls. Polymerase chain reaction restriction fragment length polymorphism (PCR‐RFLP) analysis was performed to detect three VEGF gene polymorphisms (−634 G/C, +936 C/T, and +1612 G/A) in these patients. Patients with gastric cancer had a significantly higher frequency of 1612 AA genotype (OR = 6.26, 95% CI = 1.80, 21.85; P = 0.004) than controls. Patients with cardia gastric cancer had a significantly lower frequency of AA (OR = 0.11, 95% CI = 0.01, 0.89; P = 0.04) than those with noncardia gastric cancer. Patients with Laurens diffuse‐type gastric cancer had a significantly higher frequency of AA (OR = 3.41, 95% CI = 1.22, 9.55; P = 0.02) than those with Laurens intestinal‐type gastric cancer. The −634 G/C and +936 C/T gene polymorphisms were not associated with a risk of GC and its progression. This study suggests that the VEGF +1612 G/A gene polymorphisms may be associated with gastric cancer in Chinese Han patients, and that difference in genotype distribution may be associated with the location and Laurens classification of gastric cancer. Mol. Carcinog.

Glutathione S-transferase P1 gene polymorphism associated with gastric cancer among Caucasians

Studies investigating the association between glutathione S-transferase P1 (GSTP1) codon 105 polymorphism and gastric cancer risk report conflicting results. The objective of this study was to quantitatively summarise the evidence for such a relationship. Two investigators independently searched the Medline and Embase databases. This meta-analysis included 10 case-control studies, which included 1161 gastric cancer cases and 2847 controls. The combined results based on all studies showed that there was no significant difference in genotype distribution [AA odds ratio (OR)=1.14, 95% confidence interval (CI)=0.91, 1.44; AG (OR=0.82, 95% CI=0.66, 1.03); GG (OR=1.11, 95% CI=0.55, 2.24)] between gastric cancer and non-cancer patients. When stratifying for race, results were similar except that patients with gastric cancer had a significantly higher frequency of AA (OR=1.53, 95% CI=1.14, 2.06) and lower frequency of AG (OR=0.70, 95% CI=0.55, 0.89) than non-cancer patients among Caucasians. When stratifying by the location and Laurens classification of gastric cancer, we observed no statistically significant differences in genotype distribution. This meta-analysis suggests that the GSTP1 codon 105 polymorphism may be associated with gastric cancer among Caucasians.

Does intravenous fish oil benefit patients post-surgery? A meta-analysis of randomised controlled trials.

BACKGROUND AND AIMS Supplementation of fish oil (FO) containing lipid emulsions has been associated with a reduction in the length of hospital stay, infections and liver dysfunction in patients undergoing major surgery. We carried out a meta-analysis and subgroup analysis to examine randomised clinical trial (RCT)-based evidence of the aforementioned effects. METHODS Four databases, reference lists and the WHO ICTRP were systematically searched for RCTs to access the clinical efficacy of fish oil-enriched total parenteral nutrition in post-surgery patients. Methodological quality assessment was based on the Cochrane Handbook and GRADE. RESULTS Twenty-one RCTs were enrolled for meta-analysis. FO was associated with a significant reduction in the length of hospital stay (mean = -2.14 d, 95% CI = -3.02 to -1.27), infections (OR = 0.53, 95% CI = 0.35-0.81), ALT (mean = -6.35 U/L, 95% CI = -11.75 to -0.94), GGT (mean = -11.01 U/L, 95% CI = -20.77 to -1.25) and total bilirubin (mean = -2.06 μmol/L, 95% CI = -3.6 to -0.52), as well as a non-significant change in mortality and postoperative medical cost. The quality of evidence of each clinical outcome was accessed as high. CONCLUSION FO-enriched lipid emulsions are likely to reduce infections, the length of hospital stay and liver dysfunction without influencing mortality and may be a safe and preferable choice in post-surgery patients. Further well-designed trials should be performed to determine whether FO lipid emulsions reduce mortality in patients undergoing hepatic surgery, especially liver transplantation, and the cost effectiveness of such treatment.

Use of pro-/synbiotics as prophylaxis in patients undergoing colorectal resection for cancer: a meta-analysis of randomized controlled trials.

AIMS To estimate the efficacy of pro-/synbiotics treatment in patients undergoing colorectal resection, a meta-analysis of randomized controlled trials was conducted. METHODS An electronic search of PubMed, MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Academic Search Premier, and China National Knowledge Infrastructure was performed, and RevMan 5.0 was used for statistical analysis. RESULTS Six studies including 361 patients undergoing elective colorectal surgery were retrieved. The combined analysis revealed that perioperative pro-/synbiotics administration had a positive effect on the incidence of diarrhea (OR 0.29, 95% CI 0.14 to 0.62, P=0.001), the incidence of symptomatic intestinal obstructions (OR 0.39, 95% CI 0.19 to 0.78, P=0.008), the incidence of operative total infections (OR 0.39, 95% CI: 0.22 to 0.68, P=0.0010), and pneumonia infection (OR 0.32, 95% CI 0.11 to 0.93, P=0.04). The regimen increased the numbers of Lactobacillus (MD 2.66, 95% CI: 2.13 to 3.18; P<0.00001), and decreased the counts of Enterobacteriaceae (MD -1.52, 95% CI: -1.93 to -1.11, P<0.00001). No significant differences were found between the two groups in septic morbidity, incision infection, perineal infection, intraabdominal infection, anastomotic leak, the first defecation time, length of hospital stay, mesenteric lymph nodes for bacterial translocation. No mortality related to pro-/synbiotics treatment was revealed in all studies. CONCLUSIONS Based on the meta-analysis, perioperatively use pro-/synbiotics as prophylaxis in patients undergoing colorectal resection improved clinical outcomes. The best preventive strategy (including species and the optimal dose) of pro-/synbiotics should be considered in future meta-analyses.