Singh, Siddharth

522 Background: Metformin inhibits mTOR and downstream pathways involved in cell proliferation and survival by inducing AMPK activation. Although its use has been associated with decreased risk of colorectal cancer (CRC), the effect of metformin on cancer related mortality is unclear. We performed a meta-analysis of published observational studies evaluating metformin use in patients with CRC and its association with overall and CRC-specific survival. Methods: Through a systematic search of PubMed and conference presentations (cut-off: August 2013), we identified 8 observational studies (18,537 total patients with CRC; 6242 CRC patients with DM) reporting the association between metformin use and survival after diagnosis of CRC. Summary hazard ratio (HR) with 95% confidence intervals (CI) was estimated using the random effects model, and heterogeneity was measured using the inconsistency index (I2). Results: On meta-analysis, metformin use was associated with a 34% reduction in mortality in CRC patients as compared to non-use (adjusted HR, 0.66; 95% CI, 0.54-0.81), albeit with high heterogeneity (I2=66.9%). After exclusion of one study, which contributed to considerable heterogeneity, a 28% reduction in mortality was considered a more conservative, consistent effect estimate (adjusted HR, 0.72; 95% CI, 0.64-0.81), with minimal heterogeneity (I2=16.2%). On restricting analysis only to patients with DM, use of metformin (vs non-use) was associated with decreased all-cause mortality (6 studies; adjusted HR, 0.63; 95% CI, 0.49-0.81) and CRC-specific mortality (3 studies; adjusted HR, 0.66; 95% CI, 0.50-0.87). Conclusions: Based on meta-analysis of observational studies, the use of metformin in diabetic patients with CRC appears to be associated with reduced all-cause mortality and CRC-specific mortality. Further prospective investigation of metformin’s effect on outcome in CRC patients is warranted.

11 Background: Acid-suppressive medications, particularly proton pump inhibitors (PPI), may modify risk of esophageal adenocarcinoma (EAC) in patients with Barrett’s esophagus (BE). We performed a systematic review and meta-analysis of studies evaluating the association between PPIs and histamine receptor antagonists (H2RA) and risk of EAC or high-grade dysplasia (BE-HGD) in patients with BE. Methods: Through a systematic search up to June 2013, we identified 7 observational studies (5 cohort studies and 2 case-control studies; 2,813 patients with BE, 317 cases of EAC and/or BE-HGD, 84.4% PPI users) reporting the association between PPIs or H2RA and EAC in patients with BE. Summary odds ratio (OR) with 95% confidence intervals (CI) was estimated using random effects model, and heterogeneity was measured using the inconsistency index (I2). Results: On meta-analysis, PPI use was associated with 71% reduction in EAC risk in patients with BE (adjusted OR, 0.29; 95% CI, 0.12-0.71). There was a trend toward a dose-response relationship with PPI use for >2 years protective against EAC [3 studies; PPI use >2 years vs. <2 years (as compared to no use): OR, 0.45 (0.19-1.06) vs. 1.09 (0.47-2.56)]. Considerable heterogeneity was observed in the overall analysis (I2=81%). On restricting analysis to 5 cohort studies, use of PPIs was consistently associated with a lower risk of EAC and/or BE-HGD (adjusted OR, 0.33; 95% CI, 0.19-0.58; I2=9%). H2RA use was not associated with decreased risk of EAC in patients with BE based on 2 studies (adjusted OR, 1.15; 95% CI, 0.77-1.72). Using a 67% summary risk reduction (derived from cohort studies) of EAC and/or BE-HGD with PPI use in patients with BE, and observed cumulative incidence rates of EAC and/or BE-HGD in patients with BE overall as 10.2 per 1,000 patient years, we estimate the number needed to treat with PPIs to prevent 1 case of EAC or BE-HGD in BE patients at 147. Conclusions: Based on meta-analysis of observational studies, the use of PPI, but not H2RA appears to be associated with a decreased risk of EAC and/or BE-HGD in patients with BE. PPI use should be considered in BE, and chemopreventive trials of PPIs in patients with BE are warranted.

686 Background: Preclinical evidence suggests that statins have anti-neoplastic properties by inhibiting cell proliferation, and inducing apoptosis. Statins may be associated with reduced risk of colorectal cancer (CRC), but their effect on CRC related mortality is unclear. We performed a meta-analysis of published observational studies evaluating statin use in patients with CRC and its association with overall and CRC-specific mortality. Methods: Through a systematic search upto August 2014, we identified 7 observational studies (64,773 patients with CRC;19.5% statin users) reporting the association between statin use and mortality in patients with CRC. Summary hazard ratio (HR) with 95% confidence intervals (CI) was estimated using the random effects model, and heterogeneity was measured using the inconsistency index (I2). Results: On meta-analysis, statin use was associated with a 26% reduction in all-cause mortality in CRC patients as compared to non-use (6 studies; adjusted HR, 0.74; 95% CI, 0.67-0.83) with minimal heterogeneity (I2=18%), after adjusting for age, sex and CRC stage. Only one study adjusted for concomitant metformin use. Five studies evaluated CRC-specific mortality; on meta-analysis, use of statins (vs non-use) was also associated with decreased CRC-specific mortality (adjusted HR, 0.74; 95% CI, 0.70-0.83; minimal heterogeneity, I2=17%). On limiting analysis to statin use after diagnosis of CRC, use of statins remained significantly associated with reduced CRC-specific mortality (3 studies; adjusted HR, 0.70; 95% CI, 0.60-0.81), but not overall mortality (4 studies; adjusted HR, 0.82; 95% CI, 0.64-1.05). On restricting analysis to studies, which adjusted for concomitant use of aspirin/NSAID, the inverse association between statin use and overall- (5 studies; adjusted HR, 0.74; 95% CI, 0.66-0.84) and CRC-specific mortality (4 studies; adjusted HR, 0.76; 95% CI, 0.69-0.84) remained significant. Conclusions: Based on this meta-analysis, statin use in patients with CRC may be associated with reduced all-cause and CRC-specific mortality. This observation merits prospective investigation of statins’ effect on outcome in CRC patients.

Liver fibrosis is the most important predictor of mortality in nonalcoholic fatty liver disease (NAFLD). Quantitative risk of mortality by fibrosis stage has not been systematically evaluated. We aimed to quantify the fibrosis stage–specific risk of all‐cause and liver‐related mortality in NAFLD. Through a systematic review and meta‐analysis, we identified five adult NAFLD cohort studies reporting fibrosis stage–specific mortality (0‐4). Using fibrosis stage 0 as a reference population, fibrosis stage–specific mortality rate ratios (MRRs) with 95% confidence intervals (CIs) for all‐cause and liver‐related mortality were estimated. The study is reported according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses statement. Included were 1,495 NAFLD patients with 17,452 patient years of follow‐up. Compared to NAFLD patients with no fibrosis (stage 0), NAFLD patients with fibrosis were at an increased risk for all‐cause mortality, and this risk increased with increases in the stage of fibrosis: stage 1, MRR = 1.58 (95% CI 1.19‐2.11); stage 2, MRR = 2.52 (95% CI 1.85‐3.42); stage 3, MRR = 3.48 (95% CI 2.51‐4.83); and stage 4, MRR = 6.40 (95% CI 4.11‐9.95). The results were more pronounced as the risk of liver‐related mortality increased exponentially with each increase in the stage of fibrosis: stage 1, MRR = 1.41 (95% CI 0.17‐11.95); stage 2, MRR = 9.57 (95% CI 1.67‐54.93); stage 3, MRR = 16.69 (95% CI 2.92‐95.36); and stage 4, MRR = 42.30 (95% CI 3.51‐510.34). Limitations of the study include an inability to adjust for comorbid conditions or demographics known to impact fibrosis progression in NAFLD and the inclusion of patients with simple steatosis and nonalcoholic steatohepatitis without fibrosis in the reference comparison group. Conclusion: The risk of liver‐related mortality increases exponentially with increase in fibrosis stage; these data have important implications in assessing the utility of each stage and benefits of regression of fibrosis from one stage to another. (H epatology 2017;65:1557‐1565).

SummaryBackgroundSubtotal or total colectomy or proctocolectomy with permanent ileostomy (TC‐PI) may be a treatment option for medically refractory colonic Crohn's disease (CD).AimTo perform a systematic review and meta‐analysis to evaluate the rate, risk factors and outcomes of CD recurrence after TC‐PI.MethodsIn a systematic review ending 31 March 2016, we identified 18 cohort studies (1438 adults) who underwent TC‐PI for colonic CD (median follow‐up, 7.4 years; interquartile range, 5.3–9.0). We estimated pooled rates [with 95% confidence interval (CI)] of clinical and surgical recurrence, and risk factors for disease recurrence.ResultsOn meta‐analysis, the risk of clinical recurrence after TC‐PI was 28.0% (95% CI, 21.7–35.3; 14 studies, 260/1004 patients), with a 5 and 10‐year median cumulative rate of 23.5% (range, 7–35) and 40% (range, 11–60) respectively. The risk of surgical recurrence was 16.0% (95% CI, 11.1–22.7; 10 studies; 183/1092 patients), with a 5 and 10‐year median cumulative rate of 10% (range, 3–29) and 18.5% (range, 14–34) respectively. The risk of clinical and surgical recurrence in patients without ileal disease at baseline was 11.5% (95% CI, 7.7–16.8) and 10.4% (95% CI, 4.5–22.5) respectively. History of ileal disease was associated with 3.2 times higher risk of disease recurrence (RR, 3.2; 95% CI, 1.8–5.6). Other inconsistent risk factors for disease recurrence were penetrating disease and young age at disease onset.ConclusionsSmall bowel clinical recurrence occurs in about 28% of patients after total colectomy with permanent ileostomy for colonic Crohn's disease. Disease recurrence risk is 3.2 times higher in patients with history of ileal disease, and continued medical therapy may be advisable in this population. In patients without ileal inflammation at surgery, continued endoscopic surveillance may identify asymptomatic disease recurrence to guide therapy.

SummaryBackgroundThe proportion of oesophageal adenocarcinoma that is detected concurrently with initial Barrett's oesophagus diagnosis is not well studied.AimTo compare the proportion of prevalent adenocarcinoma vs. incident adenocarcinoma found during surveillance of Barrett's.MethodsWe performed a systematic search of MEDLINE, EMBASE and Web of Science (from their inception to 31 May 2015) for cohort studies in adults with Barrett's (nondysplastic Barrett's ± Barrett's with low‐grade dysplasia) with minimum average follow‐up of 3 years, and providing numbers of prevalent adenocarcinoma detected (concurrently with Barrett's diagnosis and up to 1 year afterwards) vs. incident adenocarcinoma detected (greater than 1 year after Barrett's diagnosis). Pooled weighted proportions of prevalent and incident adenocarcinoma were calculated, using a random effects model.ResultsOn meta‐analysis of 13 studies reporting on 603 adenocarcinomas in 9657 Barrett's patients, 85.1% of adenocarcinomas were classified as prevalent [95% confidence interval (CI), 78.1–90.2%) and 14.9% as incident (95% CI, 9.8–21.9%), with substantial heterogeneity (I2 = 66%). Among nine studies reporting on 787 high‐grade dysplasia and oesophageal adenocarcinomas in 8098 Barrett's patients, the proportion of prevalent high‐grade dysplasia‐oesophageal adenocarcinoma was similar at 80.5% (95% CI, 68.1–88.8%, I2 = 87%). These results remained stable across multiple subgroup analyses including study quality, setting, duration of follow‐up and presence of baseline dysplasia.ConclusionsIn our meta‐analysis, four of five patients diagnosed with adenocarcinoma or high‐grade dysplasia at index endoscopy or within 1 year of Barrett's follow‐up were considered to be prevalent cases. Continued efforts are needed to identify patients with Barrett's before the development of adenocarcinoma.

ObjectiveIt is unclear whether isolated cutaneous lupus erythematosus (CLE) affects cardiovascular risk. We estimated the cumulative incidence and mortality of cardiovascular diseases in a population‐based CLE cohort and compared the risk with a matched non‐CLE cohort.MethodsAll incident cases of CLE in Olmsted County, Minnesota, between 1965 and 2005 were followed until December 2013. The cumulative incidence of cerebrovascular accidents (CVAs [including stroke and transient ischemic attack]), ischemic heart disease (IHD [including coronary artery disease, myocardial infarction, and angina pectoris]), heart failure, and peripheral arterial disease (PAD) was derived and compared to an age‐, sex‐, and calendar year–matched non‐CLE cohort using Cox models.ResultsThere were 155 patients with CLE (mean ± SD age at diagnosis 48 ± 16 years, 65% female, mean ± SD BMI 26.3 ± 7.1 kg/m2, 40% smokers, 9% with diabetes mellitus). During a median followup of 14.6 years, 41 CLE patients had cardiovascular events (15 patients with CVAs, 32 patients with IHD), with a 20‐year cumulative incidence of 31.6%. As compared to non‐CLE subjects, the risk of CVAs (smoking‐adjusted hazard ratio [HR] 2.97 [95% confidence interval (95% CI) 1.13–7.78]) and PAD (HR 2.06 [95% CI 0.99–4.32]) was increased in patients with CLE, but the risk of IHD was not increased (HR 0.94 [95% CI 0.57–1.54]). There was no increase in cardiovascular mortality (HR 1.68 [95% CI 0.76–3.75]). The magnitude of risk for any cardiovascular outcome was not significantly influenced by the extent of cutaneous involvement.ConclusionCLE may be associated with an increased risk of CVAs and PAD, but not IHD. Factors contributing to increased CVA risk in patients with CLE merit evaluation.

SummaryBackgroundReal‐world comparative benefits and risks of infliximab (IFX) and adalimumab (ADA) in patients with ulcerative colitis (UC) are unclear.AimTo evaluate the comparative effectiveness and safety of IFX and ADA in patients with UC who were new users of anti‐TNF agents.MethodsUsing an administrative claims database (Optum Labs Data Warehouse), we identified patients who received first anti‐TNF (IFX, ADA) prescription after a 12‐month period without any anti‐TNF treatment (baseline), and with a minimum 6‐month follow‐up after anti‐TNF initiation. Primary outcome measures were: all‐cause and UC‐related hospitalisation, abdominal surgery, corticosteroid use >60 days after starting anti‐TNF, and serious infections. We performed 2:1 propensity‐score matched Cox proportional hazard analysis, and inverse probability‐of‐treatment weight (IPTW) analysis, accounting for healthcare utilisation, comorbidities and use of UC‐related medication.ResultsWe included 1400 new users of anti‐TNF agents (age, 43 ± 15 years; 52% males), from 2006 to 2014. On propensity‐score matched analysis, there was no significant difference in the risk of UC‐related hospitalisation [IFX vs. ADA; adjusted hazard ratio (aHR), 1.04; 95% confidence interval (CI) 0.71–1.51], corticosteroid use (aHR, 0.85; 95% CI, 0.68–1.06) and serious infections (aHR, 0.62; 95% CI, 0.29–1.34) between IFX‐ and ADA‐treated patients; the number of surgical events was very small. On IPTW analysis, risk of corticosteroid use was significantly lower in IFX – as compared to ADA – treated patients (aHR, 0.82; 95% CI, 0.68–0.99). Results were stable on multiple sensitivity analyses.ConclusionsIn a large retrospective cohort of patients with UC who were new users of anti‐TNF agents, IFX‐treated patients may have lower corticosteroid use than ADA‐treated patients, but risk of hospitalisation and serious infections were comparable.