Advancements in Understanding and Preventing Obesity-Related Colon Cancer.

ABSTRACT: Obesity and colorectal cancer are global public health issues, with the prevalence of both conditions increasing over the last 4 decades. In the United States alone, the prevalence of obesity is greater than 40%, and this percentage is projected to increase past 50% by 2030. This review focuses on understanding the association between obesity and the risk of colorectal cancer while also highlighting hypotheses about molecular mechanisms underlying the link between these disease processes. We also consider whether those linkages can be disrupted via weight loss therapies, including lifestyle modifications, pharmacotherapy, bariatric surgery, and endobariatrics.

Ecosystemic Approach to Understanding Gut Microbiome-Mediated Prevention of Colorectal Cancer.

Humans and their associated microorganisms coexist in complex symbiotic relationships. Continuously advancing research is demonstrating the crucial role of host-associated microbiota in the pathophysiology and etiology of disease and in mediating the prevention thereof. As an exemplar, the gut microbiota, especially colonic bacteria, have been extensively studied in colorectal cancer (CRC), and the growing body of evidence establishes new oncomicrobes and their oncometabolites associated with the initiation and promotion of carcinogenesis. Herein, we discuss the importance of approaching the gut microbiome as an ecosystem rather than an assortment of individual factors, especially in the context of cancer prevention. Furthermore, we argue that a dietary pattern effectively drives multiple nodes of the gut microbial ecosystem toward disease- or health-promoting qualities. In the modern circumstances of excessive consumption of ultraprocessed and animal-based foods and concomitant escalation of chronic disease burden worldwide, we focus on whole food-derived dietary fiber as a key to establishing a health-promoting eubiosis in the gut.

Impact of a Pulse-Enriched Human Cuisine on Functional Attributes of the Gut Microbiome Using a Preclinical Model of Dietary-Induced Chronic Diseases.

Introducing grain legumes, i.e., pulses, into any food pattern effectively increases dietary fiber and other bioactive food components of public health concern; however, the impact depends on the amount consumed. Given the convergence of preclinical and clinical data indicating that intake of at least 300 g (1.5 cup) of cooked pulse per day has clinically observable benefit, the feasibility for a typical consumer was demonstrated by creation of a fourteen-day menu plan that met this criterion. This menu plan, named Bean Cuisine, was comprised of a combination of five cooked pulses: dry beans, chickpeas, cowpeas, dry peas, and lentils. As reported herein, the impact of each menu day of the fourteen-day plan on gut microbial composition and predicted function was evaluated in female C57BL/6J mice, a strain commonly used in studies of metabolic dysfunction-associated chronic diseases. We report that pulse-related effects were observed across a wide variety of food item combinations. In comparison to a pulse-free human cuisine, all pulse menu days enriched for a gut ecosystem were associated with changes in predicted metabolic pathways involving amino acids (lysine, tryptophan, cysteine), short-chain fatty acids (butyrate, acetate), and vitamins (B1, B6, B9, B12, K2) albeit via different combinations of microbiota, according to the PICRUSt2 estimates. The predicted metabolic functions correlating with the various pulses in the menus, indicate the value of a food pattern comprised of all pulse types consumed on a regular basis. This type of multi-pulse food pattern has the potential to enhance the taxonomic and functional diversity of the gut microbiome as a means of strengthening the resilience of the gut ecosystem to the challenges associated with the daily activities of living.

NCCN Guidelines® Insights: Rectal Cancer, Version 3.2024.

The determination of an optimal treatment plan for an individual patient with rectal cancer is a complex process. In addition to decisions relating to the intent of rectal cancer surgery (ie, curative or palliative), consideration must also be given to the likely functional results of treatment, including the probability of maintaining or restoring normal bowel function/anal continence and preserving genitourinary functions. Particularly for patients with distal rectal cancer, finding a balance between curative-intent therapy while having minimal impact on quality of life can be challenging. Furthermore, the risk of pelvic recurrence is higher in patients with rectal cancer compared with those with colon cancer, and locally recurrent rectal cancer is associated with a poor prognosis. Careful patient selection and the use of sequenced multimodality therapy following a multidisciplinary approach is recommended. These NCCN Guidelines Insights detail recent updates to the NCCN Guidelines for Rectal Cancer, including the addition of endoscopic submucosal dissection as an option for early-stage rectal cancer, updates to the total neoadjuvant therapy approach based on the results of recent clinical trials, and the addition of a "watch-and-wait" nonoperative management approach for clinical complete responders to neoadjuvant therapy.

Bariatric Surgery Is Associated with Lower Concentrations of Fecal Secondary Bile Acids and Their Metabolizing Microbial Enzymes: A Pilot Study.

INTRODUCTION: Excess body fat elevates colorectal cancer risk. While bariatric surgery (BRS) induces significant weight loss, its effects on the fecal stream and colon biology are poorly understood. Specifically, limited data exist on the impact of bariatric surgery (BRS) on fecal secondary bile acids (BA), including lithocholic acid (LCA), a putative promotor of colorectal carcinogenesis. METHODS: This cross-sectional case-control study included 44 patients with obesity; 15 pre-BRS (controls) vs. 29 at a median of 24.1 months post-BRS. We examined the fecal concentrations of 11 BA by liquid chromatography and gene abundance of BA-metabolizing bacterial enzymes through fecal metagenomic sequencing. Differences were quantified using non-parametric tests for BA levels and linear discriminant analysis (LDA) effect size (LEfSe) for genes encoding BA-metabolizing enzymes. RESULTS: Total fecal secondary BA concentrations trended towards lower levels post- vs. pre-BRS controls (p = 0.07). Individually, fecal LCA concentrations were significantly lower post- vs. pre-BRS (8477.0 vs. 11,914.0 uM/mg, p < 0.008). Consistent with this finding, fecal bacterial genes encoding BA-metabolizing enzymes, specifically 3-betahydroxycholanate-3-dehydrogenase (EC 1.1.1.391) and 3-alpha-hydroxycholanate dehydrogenase (EC 1.1.1.52), were also lower post- vs. pre-BRS controls (LDA of - 3.32 and - 2.64, respectively, adjusted p < 0.0001). Post-BRS fecal BA concentrations showed significant inverse correlations with weight loss, a healthy diet quality, and increased physical activity. CONCLUSIONS: Concentrations of LCA, a secondary BA, and bacterial genes needed for BA metabolism are lower post-BRS. These changes can impact health and modulate the colorectal cancer cascade. Further research is warranted to examine how surgical alterations and the associated dietary changes impact bile acid metabolism.

Colon Cancer, Version 3.2024, NCCN Clinical Practice Guidelines in Oncology.

Colorectal cancer (CRC) is the fourth most frequently diagnosed cancer and the second leading cause of cancer death in the United States. Management of disseminated metastatic CRC involves various active drugs, either in combination or as single agents. The choice of therapy is based on consideration of the goals of therapy, the type and timing of prior therapy, the mutational profile of the tumor, and the differing toxicity profiles of the constituent drugs. This manuscript summarizes the data supporting the systemic therapy options recommended for metastatic CRC in the NCCN Guidelines for Colon Cancer.

The impact of bariatric surgery on admissions for gastrointestinal complications and conditions associated with obesity: A nationwide study.

BACKGROUND: Obesity worsens various gastrointestinal pathologies. While bariatric surgery ameliorates obesity, it substantially modifies the gastrointestinal system depending on surgery type, with limited data on subsequent impact on obesity-related gastrointestinal admissions. METHODS: Using the 2012-2014 Nationwide Readmission Database, we included individuals with obesity who received vertical sleeve gastrectomy (VSG), Roux-en-Y gastric bypass (RYGB), or hernia repair (HR-control surgery). Our main focus was the adjusted odds ratio (aOR) for gastrointestinal inpatient admissions within 6 months following surgery compared to the 6 months preceding it, while controlling for several confounding factors. Gastrointestinal admissions were grouped into postoperative complications or obesity-associated gastrointestinal conditions. RESULTS: Our cohort included 140,103 adults with RYGB, 132,253 with VSG, and 12,436 HR controls. Postoperative gastrointestinal complications were most common after RYGB, prominently obstruction (aOR = 33.17, 95%CI: 18.01, 61.10), and Clostridium difficile infection (aOR: 12.52, 95%CI: 6.22, 25.19). VSG also saw significantly increased but less frequent similar conditions. Notably, for gastrointestinal conditions associated with obesity, acute pancreatitis risk was higher post-VSG (aOR = 6.26, 95%CI: 4.02, 9.73). Post-RYGB patients were most likely to be admitted for cholelithiasis with cholecystitis (aOR: 4.15, 95% CI: 3.24, 5.31), followed by chronic liver disease (aOR: 3.00, 95% CI: 2.33, 3.87). The risk of noninfectious colitis admissions was threefold higher after RYGB and VSG. No gastrointestinal conditions showed an increase after HR. CONCLUSION: Despite weight loss, bariatric surgery was associated with an increased risk of hepato-pancreatobiliary and colitis admissions related to obesity in the first six postoperative months, with considerable variations in rates of gastrointestinal conditions by surgery type.

Historical Obesity and Early-Onset Cancers: A Propensity-Weighted Analysis of the National Health and Nutrition Examination Survey.

BACKGROUND: The incidence of early-onset obesity-related cancers (diagnosed < 50 years) is increasing in the U.S. We examined the reported historical body mass index (BMI) of adults with early and later-onset cancers to explore relation to obesity. METHODS: We queried the 1999-2018 NHANES database for adults diagnosed with obesity-related cancers (colorectal, non-colorectal gastrointestinal, uterine, breast). We classified early and late-onset cancer based on a diagnosis age of < 50 and ≥ 50 years, respectively. Propensity-weighted analysis was used to compare prior historical BMIs between the matched groups. RESULTS: After weighing, we included 2,966,528 patients with obesity-related cancers, 846,211 (28%) of which were < 50 years. In the matched analysis, 69.1% of early-onset CRC cases were diagnosed as obese (BMI ≥ 30 kg/m2) before cancer diagnosis, compared to 47.2% of late-onset cases (p < 0.03). Similarly, a higher percentage of adults with other early-onset gastrointestinal cancers had prior obesity as compared to the late-onset cohort (70.3% vs. 40.5%, p = 0.0002). BMI showed a trend toward higher values at ages 20-24 for early-onset CRC and 30-34 for other gastrointestinal cancers. In contrast, later-onset CRC and other gastrointestinal cancers exhibited higher BMI values at later ages (30-34 and 35-39, respectively). Early-onset uterine cancer was linked to a higher BMI compared to later-onset cancer (34.0 vs. 31.1 kg/m2, p < 0.0001), with a trend towards a higher BMI before 19 years old. CONCLUSIONS: Our nationally representative data reveal that higher and earlier body fatness in adulthood associates with early-onset gastrointestinal and uterine cancers. These findings underscore the importance of intensifying efforts to combat early-life obesity.

The Risk of Colorectal Polyps after Weight Loss Therapy Versus Obesity: A Propensity-Matched Nationwide Cohort Study.

BACKGROUND: A fundamental understanding of the impact of bariatric surgery (BRS) on mechanisms of colorectal carcinogenesis is limited. For instance, studies report a reduced risk of colorectal cancer in females but not in males after BRS. We examined whether this sex-specific difference existed at the earlier polyp development stage. METHODS: This retrospective cohort study included 281,417 adults from the 2012-2020 MarketScan database. We compared polyps rates on colonoscopy in four groups: post- vs. pre-BRS (treatment) to post- vs. pre-severe obesity (SO) diagnosis (control). We focused our main analysis on a propensity-matched sample that yielded a balanced distribution of covariates in our four groups (n = 9680 adults, 21.9% males). We also adjusted for important covariates. RESULTS: Metabolic syndrome parameters improved after bariatric surgery and worsened after severe obesity diagnosis (p < 0.05). The rate of polyps was 46.7% at a median of 0.5 years pre-BRS and 47.9% at a median of 0.6 years pre-SO diagnosis. The polyps rate was 45.4% at a median (range) of 3.2 (1.0-8.5) years post-BRS. Conversely, 53.8% of adults had polyps at 3.0 (1.0-8.6) years post-SO. There was no change in the risk of colorectal polyps in males or females post- vs. pre-BRS. However, the risk of polyps was higher in males (OR = 1.32, 95% CI: 1.02-1.70) and females (OR = 1.29, 95% CI: 1.13-1.47) post- vs. pre-SO. When compared to the control group (SO), the odds ratios for colorectal polyps were lower for males and females after bariatric surgery (OR = 0.63, 95% CI: 0.44-0.90, and OR = 0.79, 95% CI: 0.66-0.96, respectively). CONCLUSIONS: Obesity is associated with an increased risk of colorectal polyps, an effect that is ameliorated after bariatric surgery. These data are relevant for studies investigating colorectal carcinogenesis mechanisms.

Distinctive patterns of sulfide- and butyrate-metabolizing bacteria after bariatric surgery: potential implications for colorectal cancer risk.

Despite improved cardiometabolic outcomes following bariatric surgery, its long-term impact on colorectal cancer (CRC) risk remains uncertain. In parallel, the influence of bariatric surgery on the host microbiome and relationships with disease outcomes is beginning to be appreciated. Therefore, we investigated the impact of Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) on the patterns of sulfide-reducing and butyrate-producing bacteria, which are hypothesized to modulate CRC risk after bariatric surgery. In this single-center, cross-sectional study, we included 15 pre-surgery subjects with severe obesity and patients who are at a median (range) of 25.6 (9.9-46.5) months after RYGB (n = 16) or VSG (n = 10). The DNA abundance of fecal bacteria and enzymes involved in butyrate and sulfide metabolism were identified using metagenomic sequencing. Differences between pre-surgery and post-RYGB or post-VSG cohorts were quantified using the linear discriminant analysis (LDA) effect size (LEfSe) method. Our sample was predominantly female (87%) with a median (range) age of 46 (23-71) years. Post-RYGB and post-VSG patients had a higher DNA abundance of fecal sulfide-reducing bacteria than pre-surgery controls (LDA = 1.3-4.4, p < .05). The most significant enrichments were for fecal E. coli, Acidaminococcus and A. finegoldii after RYGB, and for A. finegoldii, S. vestibularis, V. parvula after VSG. As for butyrate-producing bacteria, R. faecis was more abundant, whereas B. dentium and A. hardus were lower post-RYGB vs. pre-surgery. B. dentium was also lower in post-VSG vs. pre-surgery. Consistent with these findings, our analysis showed a greater enrichment of sulfide-reducing enzymes after bariatric surgery, especially RYGB, vs. pre-surgery. The DNA abundance of butyrate-producing enzymes was lower post-RYGB. In conclusion, the two most used bariatric surgeries, RYGB and VSG, are associated with microbiome patterns that are potentially implicated in CRC risk. Future studies are needed to validate and understand the impact of these microbiome changes on CRC risk after bariatric surgery.

Dietary Oncopharmacognosy as a Crosswalk between Precision Oncology and Precision Nutrition.

While diet and nutrition are modifiable risk factors for many chronic and infectious diseases, their role in cancer prevention and control remains under investigation. The lack of clarity of some diet-cancer relationships reflects the ongoing debate about the relative contribution of genetic factors, environmental exposures, and replicative errors in stem cell division as determinate drivers of cancer risk. In addition, dietary guidance has often been based upon research assuming that the effects of diet and nutrition on carcinogenesis would be uniform across populations and for various tumor types arising in a specific organ, i.e., that one size fits all. Herein, we present a paradigm for investigating precision dietary patterns that leverages the approaches that led to successful small-molecule inhibitors in cancer treatment, namely understanding the pharmacokinetics and pharmacodynamics of small molecules for targeting carcinogenic mechanisms. We challenge the scientific community to refine the paradigm presented and to conduct proof-in-concept experiments that integrate existing knowledge (drug development, natural products, and the food metabolome) with developments in artificial intelligence to design and then test dietary patterns predicted to elicit drug-like effects on target tissues for cancer prevention and control. We refer to this precision approach as dietary oncopharmacognosy and envision it as the crosswalk between the currently defined fields of precision oncology and precision nutrition with the goal of reducing cancer deaths.

Anal Carcinoma, Version 2.2023, NCCN Clinical Practice Guidelines in Oncology.

This discussion summarizes the NCCN Clinical Practice Guidelines for managing squamous cell anal carcinoma, which represents the most common histologic form of the disease. A multidisciplinary approach including physicians from gastroenterology, medical oncology, surgical oncology, radiation oncology, and radiology is necessary. Primary treatment of perianal cancer and anal canal cancer are similar and include chemoradiation in most cases. Follow-up clinical evaluations are recommended for all patients with anal carcinoma because additional curative-intent treatment is possible. Biopsy-proven evidence of locally recurrent or persistent disease after primary treatment may require surgical treatment. Systemic therapy is generally recommended for extrapelvic metastatic disease. Recent updates to the NCCN Guidelines for Anal Carcinoma include staging classification updates based on the 9th edition of the AJCC Staging System and updates to the systemic therapy recommendations based on new data that better define optimal treatment of patients with metastatic anal carcinoma.

The impact of surgical weight loss procedures on the risk of metachronous colorectal neoplasia: the differential effect of surgery type, sex, and anatomic location.

Patients with prior colorectal polyps are at high risk for metachronous colorectal neoplasia, especially in the presence of obesity. We assessed the impact of 2 common bariatric surgeries, vertical sleeve gastrectomy and roux-n-Y gastric bypass, on the risk of colorectal neoplasia recurrence. This nationally representative analysis included 1183 postbariatric adults and 3193 propensity score-matched controls, who all had prior colonoscopy with polyps and polypectomy. Colorectal polyps reoccurred in 63.8% of bariatric surgery patients and 71.7% of controls at a mean follow-up of 53.1 months from prior colonoscopy. There was a reduced odds of colorectal polyp recurrence after bariatric surgery compared with controls (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.58 to 0.83). This effect was most pronounced in men (OR = 0.58, 95% CI = 0.42 to 0.79), and post roux-n-Y gastric bypass (OR = 0.57, 95% CI = 0.41 to 0.79). However, the risk of rectal polyps or colorectal cancer remained consistent between groups. This study is the first to our knowledge to show a reduction in risk of polyp recurrence following bariatric surgery.

Rising Rates of Severe Obesity in Adults Younger Than 50 Correspond to Rise in Hospitalizations for Non-malignant Gastrointestinal Disease.

BACKGROUND: Colorectal cancer incidence is rising in adults < 50 years old, possibly due to obesity. Non-malignant colorectal conditions are understudied in this population. We hypothesize that developing severe obesity in young adulthood also corresponds with increased hospitalization rates for non-malignant colorectal conditions. METHODS: We examined annual percent change (APC) in the prevalence of obesity in adults < 50 using the 2009-2014 National Health and Nutrition Examination Survey. Using the 2010-2014 Nationwide Readmission Database, we then compared yearly hospitalization trends for various gastrointestinal conditions and their outcomes in adults < 50 with severe obesity vs. no obesity. RESULTS: The prevalence of obesity increased in adults < 50 years in 2009-2014. This increase was most pronounced for severe obesity (APC of + 12.8%). The rate of patients with severe obesity < 50 who were admitted for gastrointestinal diseases has increased by 7.76% per year in 2010-2014 (p < 0.001). This increase was > 10% per year for colorectal conditions such Clostridium difficile infections (APC + 17.3%, p = 0.002), inflammatory bowel disease (APC + 13.1%, p = 0.001), and diverticulitis (APC + 12.7%, p = 0.002). The hospitalization rate for chronic liver diseases and acute pancreatitis also increased by 12.2% and 10.0% per year, respectively (p < 0.01). In contrast, young adults without obesity had lower hospitalization rate for most gastrointestinal diseases. Furthermore, adults with no obesity had lower mortality rates for appendicitis, diverticulitis, pancreatitis and chronic liver diseases than adults with severe obesity. CONCLUSION: Our data suggest that increased adiposity in young adults is associated with more hospitalization and worse outcomes for infectious/inflammatory gastrointestinal conditions. Future prevention strategies are warranted to ameliorate these trends.

Adjustable Intragastric Balloon Leads to Significant Improvement in Obesity-Related Lipidome and Fecal Microbiome Profiles: A Proof-of-Concept Study.

INTRODUCTION: Intragastric balloons (IGBs) are a safe and effective treatment for obesity. However, limited knowledge exists on the underlying biological changes with IGB placement. METHODS: This single-institution study was part of an adjustable IGB randomized controlled trial. Subjects with obesity were randomized in a 2 is to 1 ratio to 32 weeks of IGB with diet/exercise counseling (n = 8) vs counseling alone (controls, n = 4). Diet/exercise counseling was continued for 24 weeks post-IGB removal to assess weight maintenance. We used mass spectrometry for nontargeted plasma lipidomics analysis and 16S rRNA sequencing to profile the fecal microbiome. RESULTS: Subjects with IGBs lost 15.5% of their body weight at 32 weeks vs 2.59% for controls (P < 0.05). Maintenance of a 10.5% weight loss occurred post-IGB explant. IGB placement, followed by weight maintenance, led to a -378.9 µM/L reduction in serum free fatty acids compared with pre-IGB (95% confidence interval: 612.9, -145.0). This reduction was mainly in saturated, mono, and omega-6 fatty acids when compared with pre-IGB. Polyunsaturated phosphatidylcholines also increased after IGB placement (difference of 27 µM/L; 95% confidence interval: 1.1, 52.8). Compared with controls, saturated and omega-6 free fatty acids (linoleic and arachidonic acids) were reduced after IGB placement. The fecal microbiota changed post-IGB placement and weight maintenance vs pre-IGB (P < 0.05). Further analysis showed a possible trend toward reduced Firmicutes and increased Bacteroidetes post-IGB and counseling, a change that was not conclusively different from counseling alone. DISCUSSION: IGB treatment is associated with an altered fecal microbiome profile and may have a better effect on obesity-related lipidome than counseling alone.

Colorectal Cancer Risk Is Impacted by Sex and Type of Surgery After Bariatric Surgery.

PURPOSE: Sex differences exist in the associations between obesity and the risk of colorectal cancer (CRC). However, limited data exist on how sex affects CRC risk after bariatric surgery. MATERIALS AND METHODS: This retrospective cohort study used the 2012-2020 MarketScan database. We employed a propensity-score-matched analysis and precise coding to define CRC in this nationwide US study. Adjusted hazards ratio (HR) assessed CRC risk ≥ 6 months. In a restricted analysis, logistic regression with adjusted odds ratios (OR) examined CRC risk ≥ 3 years. RESULTS: Our sample included 327,734 controls with severe obesity and 88,630 patients with Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (VSG). The odds of cessation of diabetes mellitus medications, a surrogate for diabetes remission, were higher post-surgery vs. controls, especially in RYGB and males. In females, CRC risk decreased post-RYGB compared to controls (HR = 0.40, 95%CI: 0.18-0.87, p = 0.02). However, VSG was not associated with lower CRC risk in females. Paradoxically, in males compared to controls, CRC risk trended toward an almost significant increase, especially after 3 years or more from surgery (OR = 2.18, 95%CI: 0.97-4.89, p = 0.06). Males had a higher risk of CRC, particularly rectosigmoid cancer, than females after bariatric surgery (HR = 2.69, 95% CI: 1.35-5.38, p < 0.001). Furthermore, diabetes remission was not associated with a lower CRC risk post-surgery. CONCLUSION: Our data suggest an increased risk of CRC in males compared to females after bariatric surgery. Compared to controls, there was a decrease in CRC risk in females' post-RYGB but not VSG. Mechanistic studies are needed to explain these differences.

Utility of machine learning in developing a predictive model for early-age-onset colorectal neoplasia using electronic health records.

BACKGROUND AND AIMS: The incidence of colorectal cancer (CRC) is increasing in adults younger than 50, and early screening remains challenging due to cost and under-utilization. To identify individuals aged 35-50 years who may benefit from early screening, we developed a prediction model using machine learning and electronic health record (EHR)-derived factors. METHODS: We enrolled 3,116 adults aged 35-50 at average-risk for CRC and underwent colonoscopy between 2017-2020 at a single center. Prediction outcomes were (1) CRC and (2) CRC or high-risk polyps. We derived our predictors from EHRs (e.g., demographics, obesity, laboratory values, medications, and zip code-derived factors). We constructed four machine learning-based models using a training set (random sample of 70% of participants): regularized discriminant analysis, random forest, neural network, and gradient boosting decision tree. In the testing set (remaining 30% of participants), we measured predictive performance by comparing C-statistics to a reference model (logistic regression). RESULTS: The study sample was 55.1% female, 32.8% non-white, and included 16 (0.05%) CRC cases and 478 (15.3%) cases of CRC or high-risk polyps. All machine learning models predicted CRC with higher discriminative ability compared to the reference model [e.g., C-statistics (95%CI); neural network: 0.75 (0.48-1.00) vs. reference: 0.43 (0.18-0.67); P = 0.07] Furthermore, all machine learning approaches, except for gradient boosting, predicted CRC or high-risk polyps significantly better than the reference model [e.g., C-statistics (95%CI); regularized discriminant analysis: 0.64 (0.59-0.69) vs. reference: 0.55 (0.50-0.59); P<0.0015]. The most important predictive variables in the regularized discriminant analysis model for CRC or high-risk polyps were income per zip code, the colonoscopy indication, and body mass index quartiles. DISCUSSION: Machine learning can predict CRC risk in adults aged 35-50 using EHR with improved discrimination. Further development of our model is needed, followed by validation in a primary-care setting, before clinical application.

The Impact of Bariatric Surgery on Diverticulitis Outcomes and Risk of Recurrent Hospitalizations in Adults with Clinically Severe Obesity.

PURPOSE: Clinically severe obesity (SO) is a known risk factor for worsened outcomes and recurrence of acute diverticulitis. Paucity of data exist on outcomes of diverticulitis after bariatric surgery. METHODS: The Nationwide Readmissions Database was queried for diverticulitis hospitalizations between the years 2010 and 2014. We restricted analysis to patients with SO and those who had bariatric surgery (BRS). Outcomes of mortality, surgical events, and recurrent diverticulitis admissions were compared using multivariable analysis and one-to-one propensity score matching. RESULTS: Among 52,274 diverticulitis admissions, 91.2% (47,694) patients had SO and 8.8% (4580) had prior BRS. Patients with SO had higher odds of suffering mortality on index diverticulitis admission when compared to those with prior BRS [adjusted odds ratio (aOR): 10.55; 95%CI 1.45,76.75]. Patients with SO were also more likely to undergo emergency surgery (aOR: 1.71; 95%CI 1.25,2.34) and colectomy (aOR: 1.45; 95%CI 1.26,1.68). Rates of recurrent diverticulitis readmissions within 30 days and 6 months were also higher in patients with SO compared to BRS patients (aOR: 7.94; 95%CI 1.09,57.83 and aOR: 1.98; 95%CI 1.14,3.43, respectively). Propensity score matching confirmed our findings of increased rates of mortality (OR: 17.28; 95%CI 2.02,147.6), recurrent diverticulitis, and worsened surgical outcomes within 30 days in patients with SO compared to BRS. CONCLUSION: This study is first to show improved outcomes and less recurrent hospitalizations for diverticulitis after bariatric surgery compared to patients with clinically severe obesity. Further studies are needed to understand mechanisms leading to this improvement and the role of weight loss in prevention of severe diverticulitis.

Adjustable intragastric balloon for treatment of obesity: a multicentre, open-label, randomised clinical trial.

BACKGROUND: Intragastric balloons are anatomy-preserving, minimally invasive obesity therapies. Enhanced tolerance and durability could help broaden clinical adoption. We investigated the safety and efficacy of an adjustable intragastric balloon (aIGB) in adults with obesity. METHODS: In this prospective, multicentre, open-label, randomised clinical trial done at seven US sites, adults aged 22-65 years with obesity were randomly assigned (2:1) to aIGB with lifestyle intervention or lifestyle intervention alone (control) for 32 weeks. Balloon volume could be increased to facilitate weight loss or decreased for tolerability. Coprimary endpoints included mean percentage total bodyweight loss and responder rate (≥5% total bodyweight loss) at 32 weeks. We used a multiple imputed intention-to-treat population analysis. This study was registered with ClinicalTrials.gov, NCT02812160. FINDINGS: Between Aug 9, 2016, and Dec 7, 2018, we randomly assigned 288 patients to aIGB (n=187 [65%]) or control (n=101 [35%]) groups. Mean total bodyweight loss at 32 weeks was 15·0% (95% CI 13·9-16·1) in the aIGB group versus 3·3% (2·0-4·6) in the control group (p<0·0001). Clinical response was observed in 171 (92%) patients in the aIGB group. Adjustments to the aIGB occurred in 145 (80%) patients for weight loss plateau or intolerance. Upward volume adjustment facilitated an additional mean 5·2% (4·5-5·8) total bodyweight loss. Downward volume adjustment allowed 21 (75%) patients in the aIGB group to complete the full duration of therapy. Intolerance caused early removal of the device in 31 (17%) patients. No micronutrient deficiencies were observed in the aIGB cohort. Device-related serious adverse events were observed in seven (4%) patients, without any deaths. INTERPRETATION: When aIGB was combined with lifestyle modification, significant weight loss was achieved and maintained for 6 months following removal. Balloon volume adjustability permitted individualised therapy, maximising weight loss and tolerance. FUNDING: Spatz Medical.