Is metformin use associated with a reduced risk of oesophageal cancer? A systematic review and meta-analysis.

OBJECTIVES: Studies on the association between metformin use and the risk of oesophageal cancer (OC) have generated controversial findings. This updated meta-analysis was conducted to reassess the effects of metformin on OC. METHODS: A comprehensive search strategy was conducted to select relevant studies from origination to February 2021. Heterogeneity was evaluated through the Q test and I2 statistics. HRs and 95% CIs were pooled through either random-effect or fixed-effect models. Meta-regression, subgroup analyses, sensitivity analysis and publication bias diagnosis were also performed. RESULTS: Seven studies with 5 426 343 subjects were included. Metformin use was associated with reduced risk of OC (HR=0.69, 95% CI 0.54 to 0.87, p<0.001). Sensitivity analysis suggested that the results were relatively stable. CONCLUSION: Metformin is associated with a reduced risk of OC. More well-designed studies are still needed to further elaborate on these associations. PROSPERO REGISTRATION NUMBER: CRD42021237127.

You are not lab rats at teaching hospitals: A systematic review of resident and fellow participation leads to improved colonoscopy.

BACKGROUND: Participation in colonoscopies is an essential aspect of endoscopic training. The purpose of this study was to explore the impact of fellow/trainee participation on colonoscopy outcomes. METHODS: This meta-analysis was registered on the International Prospective Register of Systematic Reviews (PROSPERO). From database inception to July 2022, studies investigating fellow involvement and colonoscopy outcomes were searched across Cochrane library, PubMed, and other databases. The random-effects model was applied to generate more conservative estimates. Sensitive analysis was conducted to explore whether the result would depend on a particular study. Egger's test and Begg's test were used to estimate the potential for publication bias. RESULTS: Seventeen studies including 30,062 participants were included. We found that fellow/trainee involvement enhanced the overall rates of adenoma detection and polyp detection (OR = 1.26, 95% CI = 1.14-1.40, p < 0.001; OR = 1.29, 95% CI = 1.02-1.63, p = 0.020, respectively). The mean number of adenoma/polyps per colonoscopy was also higher with fellow/trainee participation (MD = 0.12, 95% CI = 0.08-0.17, p < 0.001; MD = 0.15, 95% CI = 0.02-0.28, p = 0.020, respectively). CONCLUSION: In addition to its educational purpose, fellow or trainee involvement is associated with beneficial effects on colonoscopy outcomes.

Diagnostic Value, Prognostic Value, and Immune Infiltration of LOX Family Members in Liver Cancer: Bioinformatic Analysis.

Background: Liver cancer (LC) is well known for its prevalence as well as its poor prognosis. The aberrant expression of lysyl oxidase (LOX) family is associated with liver cancer, but their function and prognostic value in LC remain largely unclear. This study aimed to explore the function and prognostic value of LOX family in LC through bioinformatics analysis and meta-analysis. Results: The expression levels of all LOX family members were significantly increased in LC. Area under the receiver operating characteristic curve (AUC) of LOXL2 was 0.946 with positive predictive value (PPV) of 0.994. LOX and LOXL3 were correlated with worse prognosis. Meta-analysis also validated effect of LOX on prognosis. Nomogram of these two genes and other predictors was also plotted. There was insufficient data from original studies to conduct meta-analysis on LOXL3. The functions of LOX family members in LC were mostly involved in extracellular and functions and structures. The expressions of LOX family members strongly correlated with various immune infiltrating cells and immunomodulators in LC. Conclusions: For LC patients, LOXL2 may be a potential diagnostic biomarker, while LOX and LOXL3 have potential prognostic and therapeutic values. Positive correlation between LOX family and infiltration of various immune cells and immunomodulators suggests the need for exploration of their roles in the tumor microenvironment and for potential immunotherapeutic to target LOX family proteins.

Do proton pump inhibitors prevent Barrett's esophagus progression to high-grade dysplasia and esophageal adenocarcinoma? An updated meta-analysis.

PURPOSE: Previous research on the association between proton pump inhibitor (PPI) use and the risk of progression to high-grade dysplasia (HGD)/esophageal adenocarcinoma (EAC) in Barrett's Esophagus (BE) patients has generated inconsistent findings. This meta-analysis was performed to clarify the association. METHODS: We performed a comprehensive search strategy to select relevant studies up to September 2020. Heterogeneity was assessed using the I-squared statistic. Odds ratios (OR) and 95% confidence intervals (CI) were calculated through either fixed-effects or random-effects model. Duration-response was also performed to assess the gain effects of different PPI intake duration. Sensitivity analysis, subgroup analyses, and tests for publication bias or other small-study effects were conducted. RESULTS: Twelve studies with 155,769 subjects were included. The PPI use was associated with the reduced risk of BE progression to HGD/EAC (OR = 0.47, 95% CI = 0.32-0.71). In the duration-response analysis, the estimated OR for decreased risk of HGD/EAC with PPI intake duration of 12 months was 0.81 (95% CI = 0.71-0.91). Sensitivity analysis suggested the results of this meta-analysis were stable. No publication bias was detected. CONCLUSIONS: PPI use is associated with a decreased risk of HGD/EAC in patients with BE. For further investigation, that more well-designed studies are still needed to elucidate the protective effect of PPI usage on BE patients to prevent HGD/EAC.