Does metformin reduce the risk of cancer in obesity and diabetes? A systematic review and meta-analysis.

AIM: To evaluate the effect of metformin on cancer incidence in subjects with overweight/obesity and/or prediabetes/diabetes. MATERIALS AND METHODS: We searched MEDLINE, Embase and CENTRAL for randomized controlled trials (RCTs) in adults with overweight/obesity and/or prediabetes/diabetes that compared metformin to other interventions for ≥24 weeks. Independent reviewers selected and extracted data including population and intervention characteristics and new diagnoses of cancer. We used the RoB 2.0 risk-of-bias tool and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework to assess risk of bias and certainty of evidence. RESULTS: From 14 895 records after removal of duplicates, 27 trials were included, providing a total of 10 717 subjects in the metformin group and 10 003 in the control group, with 170 and 208 new cases of cancer, respectively. Using a random-effects model, the relative risk was 1.07 (95% confidence interval 0.87-1.31), with similar results in subgroup analyses by study duration or effect of control intervention on weight. Risk of bias in most studies was low, and no evidence of publication bias was found. Trial sequential analysis provided evidence that the cumulative sample size was large enough to exclude a significant effect of metformin on cancer incidence. CONCLUSIONS: Metformin did not reduce cancer incidence in RCTs involving subjects with overweight/obesity and/or prediabetes/diabetes.

Do GLP-1 Receptor Agonists Increase the Risk of Breast Cancer? A Systematic Review and Meta-analysis.

CONTEXT: Risk of cancer is a major concern in the development of drugs for the treatment of obesity and diabetes. In randomized controlled trials (RCTs) of the Liraglutide Clinical Development Program, subjects treated with a glucagon-like peptide-1 receptor agonist (GLP-1RA) had a higher absolute number of breast cancer events. OBJECTIVE: To assess whether patients treated with GLP-1RAs had a higher risk of breast neoplasms. DATA SOURCES: We searched MEDLINE, Embase, Web of Science, and CENTRAL from July 31, 2019 to February 8, 2020. STUDY SELECTION: Reviewers assessed abstracts and full-text articles for RCTs of GLP-1RAs in adults with excessive weight and/or diabetes and a minimum follow-up of 24 weeks. DATA EXTRACTION: Researchers extracted study-level data and assessed within-study risk of bias with the RoB 2.0 tool and quality of evidence with Grading of Recommendations Assessment, Development and Evaluation (GRADE). DATA SYNTHESIS: We included 52 trials, of which 50 reported breast cancer events and 11 reported benign breast neoplasms. Overall methodological quality was high. Among 48 267 subjects treated with GLP-1RAs, 130 developed breast cancer compared with 107 of 40 755 controls (relative risk [RR], 0.98; 95% confidence interval [CI], 0.76-1.26). Subset analyses according to follow-up, participant/investigator blinding, and type of GLP-1RA did not reveal any differences. The risk of benign breast neoplasms also did not differ between groups (RR, 0.99; 95% CI, 0.48-2.01). Trial sequential analysis provided evidence that the sample size was sufficient to avoid missing alternative results. CONCLUSIONS: Treatment with GLP-1RAs for obesity and diabetes does not increase the risk of breast neoplasms.

Esophagogastric junction outflow obstruction successfully treated with laparoscopic Heller myotomy and Dor fundoplication: First case report in the literature.

BACKGROUND: Esophagogastric junction outflow obstruction (EGJOO) is a rare syndrome, characterized by an elevation of the integrated relaxation pressure of the lower esophageal sphincter, not accompanied by alterations in esophageal motility that may lead to the criteria for achalasia. We were unable to find any prior report of the combination of Heller myotomy with anterior partial fundoplication (Dor) as the treatment for EGJOO. We herein report a case of EGJOO treated with laparoscopic Heller myotomy combined with Dor fundoplication. CASE SUMMARY: A 26-year-old man presented with a 3-year history of solid dysphagia and a 30-kg weight loss. He was treated with oral nifedipine, isosorbide, and omeprazole, without resolution of symptoms. An upper gastrointestinal series (barium swallow) revealed a "bird's beak" sign. Esophagogastroduodenoscopy was positive for Los Angeles grade A peptic esophagitis. High-resolution esophageal manometry was compatible with EGJOO. Esophageal pH monitoring showed pathological acid reflux both in orthostatic and decubitus position. An 8-cm laparoscopic Heller myotomy combined with an anterior 220° Dor fundoplication was performed. Solid diet was introduced on postoperative day 2, and the patient was discharged home the same day. At 17-mo follow-up, he reported no symptoms. Barium swallow was compatible with complete radiologic resolution. Both esophageal manometry and upper endoscopy showed normal findings 9 mo after the operation. CONCLUSION: Surgical treatment with Heller myotomy and Dor fundoplication is a potential treatment option for EGJOO refractory to medical treatment.