Obesity surgery and cancer. What are the unanswered questions?

Obesity has become a global epidemic with a soaring economic encumbrance due to its related morbidity and mortality. Amongst obesity-related conditions, cancer is indeed the most redoubtable. Bariatric surgery has been proven to be the most effective treatment for obesity and its associatedmetabolic and cardiovascular disorders. However, the understanding of whether and how bariatric surgery determines a reduction in cancer risk is limited. Obesity-related malignancies primarily include colorectal and hormone-sensitive (endometrium, breast, prostate) cancers. Additionally, esophago-gastric tumors are growing to be recognized as a new category mainly associated with post-bariatric surgery outcomes. In fact, certain types of surgical procedures have been described to induce the development and subsequent progression of pre-cancerous esophageal and gastric lesions. This emerging category is of great concern and further research is required to possibly prevent such risks. Published data has generated conflicting results. In fact, while overall cancer risk reduction was reported particularly in women, some authors showed no improvement or even increased cancer incidence. Although various studies have reported beneficial effects of surgery on risk of specific cancer development, fundamental insights into the pathogenesis of obesity-related cancer are indispensable to fully elucidate its mechanisms

Accurate liquid biopsy for the diagnosis of non-alcoholic steatohepatitis and liver fibrosis

OBJECTIVE Clinical diagnosis and approval of new medications for non-alcoholic steatohepatitis (NASH) require invasive liver biopsies. The aim of our study was to identify non-invasive biomarkers of NASH and/or liver fibrosis. DESIGN This multicentre study includes 250 patients (discovery cohort, n=100 subjects (Bariatric Surgery Versus Non-alcoholic Steato-hepatitis - BRAVES trial); validation cohort, n=150 (Liquid Biopsy for NASH and Liver Fibrosis - LIBRA trial)) with histologically proven non-alcoholic fatty liver (NAFL) or NASH with or without fibrosis. Proteomics was performed in monocytes and hepatic stellate cells (HSCs) with iTRAQ-nano- Liquid Chromatography - Mass Spectrometry/Mass Spectrometry (LC-MS/MS), while flow cytometry measured perilipin-2 (PLIN2) and RAB14 in peripheral blood CD14$^{+}$CD16$^{-}$ monocytes. Neural network classifiers were used to predict presence/absence of NASH and NASH stages. Logistic bootstrap-based regression was used to measure the accuracy of predicting liver fibrosis. RESULTS The algorithm for NASH using PLIN2 mean florescence intensity (MFI) combined with waist circumference, triglyceride, alanine aminotransferase (ALT) and presence/absence of diabetes as covariates had an accuracy of 93% in the discovery cohort and of 92% in the validation cohort. Sensitivity and specificity were 95% and 90% in the discovery cohort and 88% and 100% in the validation cohort, respectively.The area under the receiver operating characteristic (AUROC) for NAS level prediction ranged from 83.7% (CI 75.6% to 91.8%) in the discovery cohort to 97.8% (CI 95.8% to 99.8%) in the validation cohort.The algorithm including RAB14 MFI, age, waist circumference, high-density lipoprotein cholesterol, plasma glucose and ALT levels as covariates to predict the presence of liver fibrosis yielded an AUROC of 95.9% (CI 87.9% to 100%) in the discovery cohort and 99.3% (CI 98.1% to 100%) in the validation cohort, respectively. Accuracy was 99.25%, sensitivity 100% and specificity 95.8% in the discovery cohort and 97.6%, 99% and 89.6% in the validation cohort. This novel biomarker was superior to currently used FIB4, non-alcoholic fatty liver disease fibrosis score and aspartate aminotransferase (AST)-to-platelet ratio and was comparable to ultrasound two-dimensional shear wave elastography. CONCLUSIONS The proposed novel liquid biopsy is accurate, sensitive and specific in diagnosing the presence and severity of NASH or liver fibrosis and is more reliable than currently used biomarkers. CLINICAL TRIALS Discovery multicentre cohort: Bariatric Surgery versus Non-Alcoholic Steatohepatitis, BRAVES, ClinicalTrials.gov identifier: NCT03524365.Validation multicentre cohort: Liquid Biopsy for NASH and Fibrosis, LIBRA, ClinicalTrials.gov identifier: NCT04677101

Bariatric-metabolic surgery versus lifestyle intervention plus best medical care in non-alcoholic steatohepatitis (BRAVES). a multicentre, open-label, randomised trial

Background: Observational studies suggest that bariatric-metabolic surgery might greatly improve non-alcoholic steatohepatitis (NASH). However, the efficacy of surgery on NASH has not yet been compared with the effects of lifestyle interventions and medical therapy in a randomised trial. Methods: We did a multicentre, open-label, randomised trial at three major hospitals in Rome, Italy. We included participants aged 25-70 years with obesity (BMI 30-55 kg/m2), with or without type 2 diabetes, with histologically confirmed NASH. We randomly assigned (1:1:1) participants to lifestyle modification plus best medical care, Roux-en-Y gastric bypass, or sleeve gastrectomy. The primary endpoint of the study was histological resolution of NASH without worsening of fibrosis at 1-year follow-up. This study is registered at ClinicalTrials.gov, NCT03524365. Findings: Between April 15, 2019, and June 21, 2021, we biopsy screened 431 participants; of these, 103 (24%) did not have histological NASH and 40 (9%) declined to participate. We randomly assigned 288 (67%) participants with biopsy-proven NASH to lifestyle modification plus best medical care (n=96 [33%]), Roux-en-Y gastric bypass (n=96 [33%]), or sleeve gastrectomy (n=96 [33%]). In the intention-to-treat analysis, the percentage of participants who met the primary endpoint was significantly higher in the Roux-en-Y gastric bypass group (54 [56%]) and sleeve gastrectomy group (55 [57%]) compared with lifestyle modification (15 [16%]; p<0·0001). The calculated probability of NASH resolution was 3·60 times greater (95% CI 2·19-5·92; p<0·0001) in the Roux-en-Y gastric bypass group and 3·67 times greater (2·23-6·02; p<0·0001) in the sleeve gastrectomy group compared with in the lifestyle modification group. In the per protocol analysis (236 [82%] participants who completed the trial), the primary endpoint was met in 54 (70%) of 77 participants in the Roux-en-Y gastric bypass group and 55 (70%) of 79 participants in the sleeve gastrectomy group, compared with 15 (19%) of 80 in the lifestyle modification group (p<0·0001). No deaths or life-threatening complications were reported in this study. Severe adverse events occurred in ten (6%) participants who had bariatric-metabolic surgery, but these participants did not require re-operations and severe adverse events were resolved with medical or endoscopic management. Interpretation: Bariatric-metabolic surgery is more effective than lifestyle interventions and optimised medical therapy in the treatment of NASH. Funding: Fondazione Policlinico Universitario A Gemelli, Policlinico Universitario Umberto I and S Camillo Hospital, Rome, Italy

Obesity Surgery and Cancer:What Are the Unanswered Questions?

Obesity has become a global epidemic with a soaring economic encumbrance due to its related morbidity and mortality. Amongst obesity-related conditions, cancer is indeed the most redoubtable. Bariatric surgery has been proven to be the most effective treatment for obesity and its associated metabolic and cardiovascular disorders. However, the understanding of whether and how bariatric surgery determines a reduction in cancer risk is limited. Obesity-related malignancies primarily include colorectal and hormone-sensitive (endometrium, breast, prostate) cancers. Additionally, esophago-gastric tumors are growing to be recognized as a new category mainly associated with post-bariatric surgery outcomes. In fact, certain types of surgical procedures have been described to induce the development and subsequent progression of pre-cancerous esophageal and gastric lesions. This emerging category is of great concern and further research is required to possibly prevent such risks. Published data has generated conflicting results. In fact, while overall cancer risk reduction was reported particularly in women, some authors showed no improvement or even increased cancer incidence. Although various studies have reported beneficial effects of surgery on risk of specific cancer development, fundamental insights into the pathogenesis of obesity-related cancer are indispensable to fully elucidate its mechanisms

Metabolic surgery; indications and outcomes

Bariatric surgery has a large number of benefits other than weight loss, including improved control of glycemia-up to diabetes remission-, blood pressure, and dyslipidaemia, while mortality due to cardiovascular disease and female cancers are also reduced, often independent of body weight reduction. For these reason bariatric surgery was renamed as metabolic surgery. In this review of the literature we report the effects of metabolic surgery on mortality reduction, type 2 diabetes and its vascular complications, hypertension, hyperlipidemia, obstructive sleep apnea, sexual dysfunction and appetite reduction and food preferences in the short and long term

Roles of gut hormones in the regulation of food intake and body weight

The gastrointestinal tract is extremely rich in endocrine cells and secretes a myriad of hormones, including ghrelin, glucagon-like peptide 1(GLP1), gastric inhibitory peptide (GIP), cholecystokinin (CCK), amylin, peptide YY (PYY), oxyntomodulin, and leptin. Mechanical distention of the stomach elicits mechanoreceptors within the gastric wall sensing tension, stretch, and volume, which then send brain signals through vagal and spinal sensory nerves

10-Year follow-up after laparoscopic sleeve gastrectomy. Outcomes in a monocentric series

BACKGROUND: Sleeve gastrectomy (SG) has grown into the most popular bariatric operation. Nevertheless, a scarcity of long-term outcomes are available. OBJECTIVES: This study aims at evaluating the long-term percent weight loss (%WL), excess weight loss (%EWL), weight regain (WR), and co-morbidity resolution rates in a single-center cohort undergoing SG as a primary procedure, with a minimum 10-year follow-up. SETTING: University hospital, Italy. METHODS: One hundred eighty-two morbidly obese patients with body mass index (BMI) 46.6 ± 7.3 kg/m2 underwent SG. Obesity-related co-morbidities (type 2 diabetes, hypertension, sleep apnea, gastroesophageal reflux disease) were investigated. Predictors of dichotomous dependent-variable diabetes remission were computed using a binomial logistic regression. RESULTS: Patient retention rate was 77%. Mean %WL was 30.9, %EWL was 52.5%, and WR (≥25% maximum WL) occurred in 10.4%. Baseline BMI significantly (P = .001) and linearly predicted %EWL (10 yr %EWL = 18.951 + initial BMI × .74); the super-obese subgroup generated substantially greater WL compared with those with BMI <50 kg/m2 (%EWL 48.0 ± 18.5 versus 61.5 ± 23.2; P < .001). Type 2 diabetes remission occurred in 64.7%; 42.9% patients developed de novo gastroesophageal reflux disease symptoms postoperatively (P < .0001). CONCLUSIONS: SG generates sustained WL and co-morbidity resolution up to 10 years postoperatively. Although a notable portion of patients experience WR, mean %WL persists to exceed 30%, translating in adequate WL also in the long term. Additionally, WR does not seem to impact negatively on co-morbidity resolution. SG represents a safe and effective bariatric operation, which easily grants the possibility to proceed to revisional bariatric surgery in patients with WR or failure to W

The jejunum is the key factor in insulin resistance

BACKGROUND: Biliopancreatic diversion (BPD) is more effective than Roux-en-Y gastric bypass (RYGB) on both insulin resistance and diabetes. OBJECTIVES: Because the major difference between the 2 procedures resides in the length of jejunal bypass, we investigated the role of the jejunum in insulin resistance. SETTING: University hospital in Italy. METHODS: Insulin sensitivity (IS) and secretion were measured before and 4 weeks after RYGB or BPD in 16 patients. A translational study was also conducted in 6 pigs, by isolating a jejunal loop with its vascular and nerve supply (Thiry-Vella loop [TVL]). TVL was doubly stomatized and bowel continuity restored by a side-to-side jejuno-jejunostomy. At baseline and 4 weeks postoperatively a glucose bolus was injected either in the stomach or in the TVL. Whole-body IS and jejunal heat shock proteins (HSPs) were measured. Primary porcine hepatocyte cultures were incubated with plasma or individual HSPs. RESULTS: Whole-body IS increased from 353.5 ± 26.7 to 442.0 ± 37.4 (P &lt; .05) after RYGB and from 312.4 ± 14.9 to 441.2 ± 15.9 mL/m-2/min-1 (P &lt; .001) after BPD. Hepatic IS was unchanged after RYGB, while it increased from .3 ± .01 to .4 ± .1 (μM/pM) - 1 (P &lt; .01) after BPD. Total insulin secretion rate remained unchanged after RYGB but decreased (from 58.3 ± 23.6 to 33.1 ± 7.8 nmol/m-2, P &lt; .05) after BPD. Jejunectomy in pigs enhanced IS (.3 ± .01 versus .2 ± .01 mM/pM, P &lt; .001), while injection of glucose into TVL reduced it (.1 ± .01 versus .3 ± .01 mM/pM, P &lt; .0001). The jejunum secreted HSPs, Hsp70, and GRP78, which impaired insulin signaling in hepatocyte cultures. CONCLUSIONS: This study shows that jejunal bypass in both humans and pigs improves IS. Injection of glucose into the TVL in pigs determines insulin resistance. In response to glucose, the jejunum secretes HSPs that impair insulin signaling