Cancer incidence and mortality after gastric bypass surgery

Associations between Diabetes Mellitus and Selected Cancers

Cancer is one of the major causes of mortality and is the second leading cause of death. Diabetes mellitus is a serious and growing problem worldwide, and its prevalence continues to grow; it is the 12th leading cause of death. An association between diabetes mellitus and cancer has been suggested for more than 100 years. Diabetes is a common disease diagnosed among patients with cancer, and evidence indicates that approximately 8-18% of patients with cancer have diabetes, with investigations suggesting an association between diabetes and some particular cancers, increasing the risk for developing cancers such as pancreatic, liver, colon, breast, stomach, and a few others. Breast and colorectal cancers have increased from 20% to 30% and there is a 97% increased risk of intrahepatic cholangiocarcinoma or endometrial cancer. On the other hand, a number of cancers and cancer therapies increase the risk of diabetes mellitus. Complications due to diabetes in patients with cancer may influence the choice of cancer therapy. Unfortunately, the mechanisms of the associations between diabetes mellitus and cancer are still unknown. The aim of this review is to summarize the association of diabetes mellitus with selected cancers and update the evidence on the underlying mechanisms of this association.

Investigating the Relationship between Body Mass Index, Cholesterol, and Cancer in United States Adults: A Cross-Sectional Study

The purpose of this cross-sectional study was to investigate the relationship between Body Mass Index (BMI), cholesterol, and cancer in United States (US) adults. Data were collected from the 2020 Medical Expenditure Panel Survey (MEPS). Eligible participants were US adults (≥18 years) with data on BMI, cholesterol, and cancer status, who were alive at the end of the data collection period. An adjusted logistic regression model assessed associations between eight possible combinations of BMI and cholesterol status (independent variable) with cancer diagnosis (dependent variable). Among 27,805 individuals in the 2020 MEPS data, 20,818 met the eligibility criteria (weighted N = 252,340,615). Of these 2668 (weighted N = 29,770,359) had cancer and 18,150 (weighted N = 222,570,256) did not have cancer. In the adjusted logistic regression model, underweight and normal weight individuals with high cholesterol were associated with higher odds of cancer (odds ratio, OR = 2.002, and 95% confidence interval, CI = 1.032-3.885, and OR = 1.326 and 95% CI = 1.047-1.681, respectively), while obese individuals with normal cholesterol were associated with lower odds of cancer (OR = 0.681; 95% CI = 0.543-0.853) compared to normal weight individuals with normal cholesterol. This study offers insights into specific groups of individuals who may be prioritized for cancer prevention. Further research is required to investigate these findings in additional subpopulations.

Risk of Esophageal Adenocarcinoma After Bariatric Surgery: A Meta-Analysis of Retrospective Studies

PURPOSE

This study aims to systematically review and meta-analyze the evidence on the risk of esophageal adenocarcinoma (EAC) following metabolic and bariatric surgery (MBS).

MATERIALS AND METHODS

A systematic literature search was conducted on the China National Knowledge Infrastructure (CNKI), Wanfang, EMBASE, MEDLINE, Web of Science, The Cochrane Library, and PubMed databases. Meta-analysis utilized odds ratios (ORs) and 95% confidence intervals (CIs) to analyze the correlation between MBS and the risk of EAC. Meta-analysis was performed using STATA software (version 12.0).

RESULTS

Fourteen studies involving patients with obesity undergoing bariatric surgery and control groups receiving conventional treatment were included. The meta-analysis indicated a reduction in the overall incidence of esophageal cancer after bariatric surgery (OR = 0.69, 95% CI: 0.51-0.95, P = 0.022). Subgroup analysis results demonstrated a decreased risk of EAC in European patients with obesity undergoing MBS treatment (OR: 0.60, 95% CI: 0.38-0.95, P = 0.028). In studies with a sample size greater than or equal to 100,000 patients, the risk of EAC in patients with obesity undergoing MBS was significantly lower than the non-surgery group (OR: 0.59, 95% CI: 0.42-0.83, P = 0.003). Articles published before 2020 and those published in 2020 or earlier showed a significant difference in the incidence of EAC between the surgery and non-surgery groups (OR: 0.57, 95% CI: 0.43-0.75, P < 0.001). The risk of EAC in patients with obesity with a follow-up time of less than 5 years was statistically significant (OR: 0.46, 95% CI: 0.25-0.82, P = 0.009).

CONCLUSION

Our meta-analysis results suggest a reduced risk of esophageal cancer in patients with obesity after bariatric surgery.

PROSPERO REGISTRATION

CRD 42024505177.

Incidence of cancer for patients after bariatric surgery: evidence from 33 cohort studies

BACKGROUND

With the rising prevalence of severe obesity, bariatric surgery has emerged as a crucial treatment option. As the number of surgeries performed worldwide increases, there has been growing interest in the impact of bariatric surgery on cancer incidence. While several studies have examined this relationship, the topic remains controversial.

OBJECTIVES

We conducted this systematic review of cohort studies with meta-analysis to evaluate the effect of bariatric surgery versus nonsurgical treatment on overall cancer incidence. However, the effects may vary when focusing on specific cancer types, surgical procedures, or gender, so we conducted additional subgroup analyses.

SETTING

A meta-analysis. University hospital.

METHODS

The Cochrane, Embase, PubMed, and Web of Science databases were searched for studies from 1 January 2000 to 1 December 2022. Meta-analysis was conducted to evaluate the pooled effect and further implemented subgroup analysis stratified by cancer type, operation type, and sex.

RESULTS

All cohort studies were included in this meta-analysis from 18,216 studies. The overall cancer incidence demonstrated a significant decrease in the group with bariatric surgery (odds ratios [OR] = .56, P = .000, 95% CI .46 to .68). In subgroup analysis, similar decrease effect was found in 9 cancers. Furthermore, the incidence of cancer decreased significantly in male (OR = .66, P = .001, 95% CI .51 to .85) and female patients (OR = .63, P = .000, 95% CI .57 to .69) and patients undergoing gastric bypass (OR = .46, P = .000, 95% CI .33 to .63) or sleeve gastrectomy (OR = .44, P = .001, 95% CI .27 to .70).

CONCLUSIONS

In the overall analysis, bariatric surgery could reduce the incidence of cancer significantly. Further large-scale well-matched studies are needed to verify the protective effect of bariatric surgery on cancer incidence.

Correlation Between Bariatric Surgery and the Risk of Multiple Myeloma: Results from an Evidence-Based Strategy

OBJECTIVE

We conducted a meta-analysis of current literature to assess whether bariatric surgery(BS) has a positive effect on reducing the risk of multiple myeloma(MM).

METHODS

Relevant studies meeting the criteria were systematically reviewed using databases such as PubMed, Web of Science, Embase (Ovid platform), MEDLINE, and the Cochrane Library. The meta-analysis utilized hazard ratios (RR) and 95% confidence intervals (CI) to analyze the correlation between BS and the risk of MM. STATA software (version 12.0) was employed for the meta analysis.

RESULTS

The meta-analysis included 10 eligible studies, involving 2,452,503 patients with obesity. The results demonstrated a significant reduction in the risk of multiple myeloma in patients with obesity after bariatric surgery compared to non-surgical patients with obesity (RR = 0.51, 95%CI: 0.31-0.84). Subgroup analyses revealed a decreased probability of developing multiple myeloma in European patients with obesity and North American patients with obesity who underwent bariatric surgery. Studies with a sample size greater than or equal to 100,000 indicated a significantly reduced risk of multiple myeloma in patients with obesity undergoing bariatric surgery compared to the non-surgical group (RR: 0.45, 95%CI: 0.23-0.88, P < 0.02). Two publications before 2010 showed no significant difference in the incidence of multiple myeloma between the surgical and non-surgical groups (RR: 0.61, 95% CI: 0.14-2.63, P = 0.504), while publications after 2010 demonstrated a reduced incidence in the surgical group (RR: 0.51, 95% CI: 0.30-0.86, P = 0.012).

CONCLUSION

Our meta-analysis results suggest a reduced risk of multiple myeloma in patients with obesity following bariatric surgery.

PROSPERO REGISTRATION

CRD42023485668.

Obesity: current state of the problem, multidisciplinary approach. (based on the consensus of the World Gastroenterological Organization “Obesity 2023” and the European guideline on obesity care in patients with gastrointestinal and liver diseases, 2022)

Obesity is the largest pandemic in the world, and its prevalence continues to increase. The purpose of the presented publication is to raise awareness of doctors about modern methods of diagnosing obesity and approaches to therapy, using an interdisciplinary team approach similar to that used in other chronic diseases, such as diabetes, heart disease and cancer. The article presents data from the World Gastroenterological Organization (2023) and the European Guidelines for the Treatment of Obesity in patients with diseases of the gastrointestinal tract and liver (2022). According to modern approaches, obesity should be considered as a chronic recurrent progressive disease, the treatment of which requires a comprehensive interdisciplinary approach involving psychologists and psychiatrists, nutritionists/nutritionists, therapists, endoscopists and surgeons, including lifestyle changes, a well-defined diet and exercise regimen, drug therapy, endoscopic or surgical methods of treatment. Conclusions. In order to stop the growing wave of obesity and its many complications and costs, doctors, insurance companies and health authorities should make systematic efforts to raise public awareness of both the adverse health risks associated with obesity and the potential reduction of risks through a comprehensive approach to therapy.

Bariatric Surgery and Longitudinal Cancer Risk: A Review

Importance

Cancer is one of the leading causes of death in the United States, with the obesity epidemic contributing to its steady increase every year. Recent cohort studies find an association between bariatric surgery and reduced longitudinal cancer risk, but with heterogeneous findings.

Observations

This review summarizes how obesity leads to an increased risk of developing cancer and synthesizes current evidence behind the potential for bariatric surgery to reduce longitudinal cancer risk. Overall, bariatric surgery appears to have the strongest and most consistent association with decreased incidence of developing breast, ovarian, and endometrial cancers. The association of bariatric surgery and the development of esophageal, gastric, liver, and pancreas cancer is heterogenous with studies showing either no association or decreased longitudinal incidences. Conversely, there have been preclinical and cohort studies implying an increased risk of developing colon and rectal cancer after bariatric surgery. A review and synthesis of the existing literature reveals epidemiologic shortcomings of cohort studies that potentially explain incongruencies observed between studies.

Conclusions and Relevance

Studies examining the association of bariatric surgery and longitudinal cancer risk remain heterogeneous and could be explained by certain epidemiologic considerations. This review provides a framework to better define subgroups of patients at higher risk of developing cancer who would potentially benefit more from bariatric surgery, as well as subgroups where more caution should be exercised.

Global burden of esophageal cancer attributable to high BMI in 204 countries and territories: 1990-2019

BACKGROUND

Esophageal cancer (EC), a common and fatal disease, includes two histological subtypes; esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (ECA). To aid policymakers in the allocation of resources for the prevention and treatment of EC, updated data on EC deaths and disability-adjusted life years (DALYs) attributable to high body mass index (BMI) are necessary. The objective of this study was to identify trends in EC associated with high BMI between 1990 and 2019 using 2019 Global Burden of Disease data.

METHODS

In this observational population-based study, epidemiological data on the association between high BMI and EC were obtained from GBD 2019. The age-standardized mortality rate (ASMRs) and disability-adjusted life year rate (ASDRs) attributable to high BMI-related EC were stratified by year, age, country, and sociodemographic index (SDI). The estimated annual percentage change (EAPC) was calculated to evaluate the temporal trends of the ASMRs and ASDRs between 1990 and 2019.

RESULTS

In 2019, the proportion of EC deaths and DALYs attributed to high BMI was 18.1% and 18.9%, respectively, resulting in 89 904 (95% confidence interval [CI]: 27 879-171 255) deaths and 2 202 314 (95% CI: 681 901-4 173 080) DALYs. High BMI-related deaths and DALYs showed a strong upward trend, increasing by more than two-fold since 1990. East Asia and Western Europe showed the highest risk of EC mortality and DALYs attributable to high BMI; China and the USA bear the greatest burden. The ASMR and ASDR increased in five SDI regions.

CONCLUSIONS

The incidence of EC is increasing, particularly in developing nations, which may be attributed to the prevalence of high BMI. To mitigate the impact of high BMI on the incidence of EC, it is important to increase awareness of its deleterious effects, which may alleviate the burden of this disease.

Trends in the burden of most common obesity-related cancers in 16 Southern Africa development community countries, 1990-2019. Findings from the global burden of disease study

Background

Obesity-related cancers in the 16 Southern African Development Community (SADC) countries is quite prominent. The changes and time trends of the burden of obesity-related cancers in developing countries like SADC remain largely unknown. A descriptive epidemiological analysis was conducted to assess the burden of obesity-related cancers, (liver, esophageal, breast, prostate, colon/rectal, leukemia, ovarian, uterine, pancreatic, kidney, gallbladder/biliary tract, and thyroid cancers) in SADC countries.

Methods

Data from the 2019 Global Burden of Diseases Study was used. Deaths extracted from vital registration, verbal autopsies and ICD codes. Cancer-type, mortality and prevalence per 100,000 population and 95% uncertainty intervals (UIs) were calculated using the Cause of Death Ensemble model and Spatio-Temporal Gaussian process with mixed effects regression models. Annual rates of change (AROCs) between 1990 and 2019 and the corresponding UIs were calculated.

Results

The top age-standardized mortality rates per 100,000 in 2019 for males were leukemia, 20.1(14.4-26.4), esophageal cancer, 15.1 (11.2-19.1), and colon and rectal cancer, 10.3 (8.6-12.6). For females, breast cancer, 20.6 (16.6-25.0), leukemia, 17.1 (11.4-23.7), and esophageal cancer, 8.3 (5.5-10.7), had the leading mortality rates. For males, AROC substantial (p < 0.05) increase for kidney cancer for 11 of the countries (AROC from 0.41% to 1.24%), colon cancer for eight of the countries (from 0.39% to 0.92%), and pancreatic cancer for seven countries (from 0.26% to 1.01%). In females, AROC showed substantial increase for pancreatic cancer for 13 of the countries from (0.34%-1.67%), nine countries for kidney cancer (from 0.27% to 1.02%), seven countries each for breast cancer (0.35%-1.13%), and ovarian cancer (from 0.33% to 1.21%).

Conclusions

There is need for location-specific and culturally appropriate strategies for better nutrition and weight control, and improved screening for all cancers. Health promotion messaging should target kidney, colon, pancreatic, and breast cancers and encourage clinically tested methods of reducing BMI such as increasing personal physical activity and adoption of effective dietary regimes.

Clinical significance of colonoscopy before laparoscopic bariatric/metabolic surgery in Japanese patients

PURPOSE

Obesity is known to be associated with colorectal adenoma (CRA) and colorectal cancer (CRC); yet colonoscopy is not considered an essential preoperative evaluation before bariatric/metabolic surgery. The aim of this study was to clarify the clinical significance of preoperative colonoscopy for obese Japanese patients.

METHODS

The subjects of this retrospective study were 114 patients who underwent screening colonoscopy before bariatric/metabolic surgery. Multivariate analyses were performed to evaluate the independent predictors of CRA/CRC among the characteristics identified as significant or nearly significant by univariate analyses.

RESULTS

Colonoscopy revealed abnormal findings indicating the need for biopsy or polypectomy in 20 of the 114 patients (17.5%), and CRA was diagnosed in 13 patients (11.4%). Three patients (2.6%), who were all ≥ 56 years old, had a CRA ≥ 10 mm in diameter. The multivariate analysis showed that older age and male sex were significant predictors of CRA/CRC, which was identified in 46.2% of the male patients aged ≥ 46 years.

CONCLUSION

Our findings suggest that older age and male sex may be risk factors for CRA/CRC in obese Japanese candidates for bariatric/metabolic surgery; thus, preoperative colonoscopy should be considered for these high-risk patients.

The interplay of obesity, microbiome dynamics, and innovative anti-obesity strategies in the context of endometrial cancer progression and therapeutic approaches

Endometrial cancer (EC) is the most common gynecologic malignancy in the United States, and its incidence and mortality are rising. Obesity is more tightly associated with EC than any other cancer. Thus, the rising prevalence of obesity and associated risk factors, including diabetes and insulin resistance, cause alarm. The metabolic derangements of obesity increase the bioavailability of estrogen, hyperinsulinemia, and inflammation in a complex system with direct and indirect effects on the endometrium, resulting in proliferation and, ultimately, carcinogenesis. In addition, the gut dysbiosis associated with obesity helps contribute to these metabolic derangements, priming an individual for developing EC and perhaps affecting treatment efficacy. More recent studies are beginning to explore obesity's effect on the local tumor microbiome of EC and its role in carcinogenesis. Significant and sustained weight loss in individuals can considerably decrease the risk of EC, likely through reversal of the altered metabolism and dysbiosis resulting obesity. Bariatric surgery is the gold standard for successful weight loss and highlights how reversing of the systemic effects of obesity can reduce EC risk. However, the current limited availability, knowledge, and imposed stigma of bariatric surgery prohibits population-level reductions in EC. Therefore, effective and maintainable non-surgical dietary and pharmacologic interventions are needed.

Life expectancy after bariatric surgery or usual care in patients with or without baseline type 2 diabetes in Swedish Obese Subjects

OBJECTIVES

To determine life expectancy and causes of death after bariatric surgery in relation to baseline type 2 diabetes (T2D) in the prospective, Swedish Obese Subjects study.

METHODS

The study included 2010 patients with obesity who underwent bariatric surgery and 2037 matched controls, eligible for surgery. The surgery group underwent gastric bypass (n = 265), banding (n = 376), or vertical banded gastroplasty (n = 1369). The control group (n = 2037) received usual obesity care. Causes of death were obtained from the Swedish Cause of Death Register, case sheets and autopsy reports, in patients with baseline T2D (n = 392 surgery patients/n = 305 controls) or non-T2D (n = 1609 surgery patients/n = 1726 controls) during a median follow-up 26 years.

RESULTS

In T2D and non-T2D subgroups, bariatric surgery was associated with increased life expectancy (2.1, 95% confidence interval (95% CI) 0.2-4.0; and 1.6, 0.5-2.7 years, respectively) and reduced overall mortality (adjusted hazard ratio (adjHR) = 0.77, 95% CI: 0.61-0.97; and 0.82, 0.72-0.94, respectively), and the treatment benefit was similar (interaction p = 0.615). Bariatric surgery was associated with reduced cardiovascular mortality in both subgroups (adjHR = 0.65, 95% CI: 0.46-0.91; and 0.70, 0.55-0.88, respectively (interaction p = 0.516)).

CONCLUSIONS

Bariatric surgery is associated with similar reduction of overall and cardiovascular mortality and increased life expectancy regardless of baseline diabetes status.

Does weight loss in women with obesity induce regression of endometrial hyperplasia? A systematic review

Obesity is a leading risk factor for endometrial cancer and its precursor, endometrial hyperplasia (EH). Currently, weight loss is recommended for people with EH and obesity, but evidence to guide weight management as primary or adjunctive therapy is limited. This systematic review aims to assess the role of weight loss in inducing histopathological regression of EH in women with obesity. A systematic search of Medline, PubMed, Embase and The Cochrane Library databases was conducted in January 2022. Studies reporting on participants with EH who underwent weight loss interventions, incorporating comparisons of pre- and post-intervention histology, were included. Studies were limited to those published in English with full text available. Six studies met the inclusion criteria, all of which reported outcomes after bariatric surgery. Three studies reported outcomes for the same group of participants, therefore only one outcome set was included. Pre-operative endometrial biopsy results were available for 167 women, and 81 had post-operative biopsies reported. Nineteen women (11.4% of those biopsied) had EH pre-operatively; 17 underwent repeat sampling post-operatively. Twelve (71%) had complete histological resolution, 1 (6%) had partial regression from complex hyperplasia to simple hyperplasia, 1 (6%) had persistent atypical hyperplasia, and 3 (18%) had persistent simple hyperplasia. One patient with a normal pre-intervention biopsy had simple hyperplasia post-operatively. Due to poor quality and overall scarcity of data, the role of weight loss in the primary or adjunctive treatment of EH is unknown. Future studies should prospectively assess weight loss modalities and targets, as well as use of concurrent therapies.

Long-term cancer outcomes after bariatric surgery

OBJECTIVE

Obesity is associated with increased cancer risk. Because of the substantial and sustained weight loss following bariatric surgery, postsurgical patients are ideal to study the association of weight loss and cancer.

METHODS

Retrospectively (1982-2019), 21,837 bariatric surgery patients (surgery, 1982-2018) were matched 1:1 by age, sex, and BMI with a nonsurgical comparison group. Procedures included gastric bypass, gastric banding, sleeve gastrectomy, and duodenal switch. Primary outcomes included cancer incidence and mortality, stratified by obesity- and non-obesity-related cancers, sex, cancer stage, and procedure.

RESULTS

Bariatric surgery patients had a 25% lower risk of developing any cancers compared with a nonsurgical comparison group (hazard ratio [HR] 0.75; 95% CI 0.69-0.81; p < 0.001). Cancer incidence was lower among female (HR 0.67; 95% CI 0.62-0.74; p < 0.001) but not male surgery patients, with the HR lower for females than for males (p < 0.001). Female surgery patients had a 41% lower risk for obesity-related cancers (i.e., breast, ovarian, uterine, and colon) compared with nonsurgical females (HR 0.59; 95% CI 0.52-0.66; p < 0.001). Cancer mortality was significantly lower after surgery in females (HR 0.53; 95% CI 0.44-0.64; p < 0.001).

CONCLUSIONS

Bariatric surgery was associated with lower all-cancer and obesity-related cancer incidence among female patients. Cancer mortality was significantly lower among females in the surgical group versus the nonsurgical group.

Context-dependent environmental associations with endometrial cancer histotype and genotype

OBJECTIVE

MLH1 loss due to MLH1 methylation, detected during Lynch syndrome screening, is one of the most common molecular changes in endometrial cancer. It is well established that environmental influences such as nutritional state can impact gene methylation, both in the germline and in a tumor. In colorectal cancer and other cancer types, aging is associated with changes in gene methylation. The objective of this study was to determine if there was an association between aging or body mass index on MLH1 methylation in sporadic endometrial cancer.

METHODS

A retrospective review of patients with endometrial cancer was performed. Tumors were screened for Lynch syndrome via immunohistochemistry, with MLH1 methylation analysis performed when there was loss of MLH1 expression. Clinical information was abstracted from the medical record.

RESULTS

There were 114 patients with mismatch repair deficient tumors associated with MLH1 methylation, and 349 with mismatch repair proficient tumors. Patients with mismatch repair deficient tumors were older than those whose tumors were proficient. Mismatch repair deficient tumors had a higher incidence of lymphatic/vascular space invasion. When stratified by endometrioid grade, associations with body mass index and age became apparent. Patients with endometrioid grades 1 and 2 tumors and somatic mismatch repair deficiency were significantly older, but body mass index was comparable with that of the mismatch repair intact group. For endometrioid grade 3, patient age did not significantly vary between the somatic mismatch repair deficient group and the mismatch repair intact group. In contrast, body mass index was significantly higher in the patients with grade 3 tumors with somatic mismatch repair deficiency.

CONCLUSION

The relationship of MLH1 methylated endometrial cancer with age and body mass index is complex and somewhat dependent on tumor grade. As body mass index is modifiable, it is possible that weight loss induces a 'molecular switch' to alter the histologic characteristics of an endometrial cancer.

The Impact of Bariatric Surgery on the Incidence of Colorectal Cancer in Patients with Obesity-a Systematic Review and Meta-analysis of Registry Data

PURPOSE

Cancer and obesity represent two of the most significant global health concerns. The risk of malignancy, including colorectal cancer (CRC), increases with obesity. The aim of this study was to perform a systematic review and meta-analysis to determine the value of bariatric surgery in reducing CRC risk in patients with obesity using registry data.

MATERIALS AND METHODS

A systematic review and meta-analysis were performed as per PRISMA guidelines. The risk of CRC was expressed as a dichotomous variable and reported as odds ratios (OR) with 95% confidence intervals (CIs) using the Mantel-Haenszel method. A multi-treatment comparison was performed, examining the risk reduction associated with existing bariatric surgery techniques. Analysis was performed using RevMan, R packages, and Shiny.

RESULTS

Data from 11 registries including 6,214,682 patients with obesity were analyzed. Of these, 14.0% underwent bariatric surgery (872,499/6,214,682), and 86.0% did not undergo surgery (5,432,183/6,214,682). The mean age was 49.8 years, and mean follow-up was 5.1 years. In total, 0.6% of patients who underwent bariatric surgery developed CRC (4,843/872,499), as did 1.0% of unoperated patients with obesity (54,721/5,432,183). Patients with obesity who underwent bariatric surgery were less likely to develop CRC (OR: 0.53, 95% CI: 0.36-0.77, P < 0.001, I2 = 99%). Patients with obesity undergoing gastric bypass surgery (GB) (OR: 0.513, 95% CI: 0.336-0.818) and sleeve gastrectomy (SG) (OR: 0.484, 95% CI: 0.307-0.763) were less likely to develop CRC than unoperated patients.

CONCLUSION

At a population level, bariatric surgery is associated with reduced CRC risk in patients with obesity. GB and SG are associated with the most significant reduction in CRC risk.

PROSPERO REGISTRATION

CRD42022313280.

Obesity-associated cancer risk reduction after metabolic surgery: insights from the SPLENDID study and the path forward

Obesity incidence continues to rise globally along with obesity-associated conditions, which heavily burden individuals' quality of life and healthcare systems. Evidence regarding the power of metabolic and bariatric surgery to treat obesity has, fortunately, brought to light how substantial and sustained weight loss can mitigate adverse clinical outcomes of obesity and metabolic disease. Obesity-associated cancer has been an important focus of studies in recent decades to further elucidate what impact metabolic surgery could have on incidence of cancer and cancer-related mortality. The SPLENDID (Surgical Procedures and Long-term Effectiveness in Neoplastic Disease Incidence and Death) study is one of the recent large cohort studies that highlights the power of substantial weight loss and the long-term benefits to patients with obesity in preventing cancer. This review of SPLENDID aims to highlight both consistency of results with prior studies and new findings unexplored previously.

Bariatric surgery in the prevention of obesity-associated cancers: mechanistic implications

Obesity is associated with an increased risk of at least 13 different cancers, as well as worse cancer outcomes and increased cancer mortality. As rates continue to rise both in the United States and worldwide, obesity is poised to become the leading lifestyle-related risk factor for cancer. Currently, the most effective treatment for patients with severe obesity is bariatric surgery. Multiple cohort studies have demonstrated a consistent >30% decreased risk of cancer incidence in women, but not men, following bariatric surgery. However, the physiologic mechanisms driving obesity-associated cancer and the cancer-protective effect of bariatric surgery are not clearly defined. In this review, we highlight emerging concepts in the mechanistic understanding of obesity-associated cancer. Evidence from both human studies and preclinical animal models suggest that obesity drives carcinogenesis through dysregulation of systemic metabolism, immune dysfunction, and an altered gut microbiome. Additionally, we present related findings to suggest that bariatric surgery may disrupt and even reverse many of these mechanisms. Finally, we discuss the use of preclinical bariatric surgery animal models in the study of cancer biology. The prevention of cancer is emerging as an important indication for bariatric surgery. Elucidating the mechanisms through which bariatric surgery limits carcinogenesis is critical to developing a variety of interventions that intercept obesity-driven cancer.

Obesity, cancer, and response to immune checkpoint inhibitors: Could the gut microbiota be the mechanistic link?

Immune checkpoint inhibitors (ICI) have deeply changed the therapeutic management of a broad spectrum of solid tumors. Recent observations showed that obese patients receiving ICIs might have better outcomes than those with normal weight, while obesity was historically associated with a worse prognosis in cancer patients. Of note, obesity is associated with alterations in the gut microbiome profile, which interacts with immune and inflammatory pathways, both at the systemic and intratumoral levels. As the influence of the gut microbiota on the response to ICI has been repeatedly reported, a specific gut microbiome profile in obese cancer patients may be involved in their better response to ICI. This review summarizes recent data on the interactions between obesity, gut microbiota, and ICIs. In addition, we highlight possible pathophysiological mechanisms supporting the hypothesis that gut microbiota could be one of the links between obesity and poor response to ICIs.

Impact of bariatric surgery on early-onset colorectal cancer risk: a systematic review and meta-analysis

The aim of this meta-analysis is to determine the impact of bariatric surgery on the risk of early-onset colorectal neoplasia. This systematic review was conducted according to PRISMA recommendations. It was registered in the PROSPERO international database. A comprehensive search was conducted in electronic databases (MEDLINE, EMBASE, and Web of Science) for completed studies until May 2022. The Search was made using a mixture of indexed terms and title, abstract and keywords. The search included terms: obese, surgical weight loss intervention, colorectal cancer, and colorectal adenomas. Studies that included bariatric intervention patient's vs non-surgical obese patients younger than 50 years were considered. Inclusion criteria were patients with BMI more than 35 kg/m² who underwent a colonoscopy. Studies with follow-up colonoscopy performed in less than 4 years after bariatric surgery and those that evaluated patients with a mean age difference of 5 or more years between groups were excluded. Outcomes analyzed in obese patients with surgical treatment vs control patients included colorectal cancer incidence. From 2008 to 2021, a total of 1536 records were identified. Five retrospective studies that included 48,916 patients were analyzed. Follow-up period ranged from 5 to 22.2 years. 20,663 (42.24%) patients underwent bariatric surgery and 28,253 (57.76%) were part of the control patients. Roux-en-Y gastric bypass was performed in 14,400 (69.7%) individuals. The intervention and control group were similar in age range, proportion of female participants and initial body mass index (35-48.3 vs 35-49.3, respectively). 126/20663 (0.61%) patients in the bariatric surgery group and 175/28253 (0.62%) individuals in the control group presented CRC. In this meta-analysis, we were unable to demonstrate a significant impact of the Bariatric Surgery on EOCRC risk. Prospective trials with longer follow-up periods should be done to prove the colorectal cancer risk reduction.

Obesity, the Adipose Organ and Cancer in Humans: Association or Causation?

Epidemiological observations, experimental studies and clinical data show that obesity is associated with a higher risk of developing different types of cancer; however, proof of a cause-effect relationship that meets the causality criteria is still lacking. Several data suggest that the adipose organ could be the protagonist in this crosstalk. In particular, the adipose tissue (AT) alterations occurring in obesity parallel some tumour behaviours, such as their theoretically unlimited expandability, infiltration capacity, angiogenesis regulation, local and systemic inflammation and changes to the immunometabolism and secretome. Moreover, AT and cancer share similar morpho-functional units which regulate tissue expansion: the adiponiche and tumour-niche, respectively. Through direct and indirect interactions involving different cellular types and molecular mechanisms, the obesity-altered adiponiche contributes to cancer development, progression, metastasis and chemoresistance. Moreover, modifications to the gut microbiome and circadian rhythm disruption also play important roles. Clinical studies clearly demonstrate that weight loss is associated with a decreased risk of developing obesity-related cancers, matching the reverse-causality criteria and providing a causality correlation between the two variables. Here, we provide an overview of the methodological, epidemiological and pathophysiological aspects, with a special focus on clinical implications for cancer risk and prognosis and potential therapeutic interventions.

Obesity and cancer stem cells: Roles in cancer initiation, progression and therapy resistance

Obesity, the global pandemic since industrialization, is the number one lifestyle-related risk factor for premature death, which increases the incidence and mortality of various diseases and conditions, including cancer. In recent years, the theory of cancer stem cells (CSCs), which have the capacity for self-renewal, metastasis and treatment resistance, has been bolstered by increasing evidence. However, research on how obesity affects CSCs to facilitate cancer initiation, progression and therapy resistance is still in its infancy, although evidence has already begun to accumulate. Regarding the ever-increasing burden of obesity and obesity-related cancer, it is pertinent to summarize evidence about the effects of obesity on CSCs, as elucidating these effects will contribute to the improvement in the management of obesity-related cancers. In this review, we discuss the association between obesity and CSCs, with a particular focus on how obesity promotes cancer initiation, progression and therapy resistance through CSCs and the mechanisms underlying these effects. In addition, the prospect of preventing cancer and targeting the mechanisms linking obesity and CSCs to reduce cancer risk or to improve the survival of patients with cancer is considered.

The Impact of Bariatric Surgery on Pancreatic Cancer Risk: a Systematic Review and Meta-Analysis

A growing body of evidence suggests that bariatric surgery is associated with a reduced risk of some cancers. This meta-analysis aims to determine whether bariatric surgery affects pancreatic cancer risk. We conducted a comprehensive literature search of PubMed, Embase, and Web of Science databases. Fixed-effect models were used to estimate pooled data and presented as odds ratio (OR) and 95% confidence interval (CI). Heterogeneity was assessed using the Cochran Q test and I² test. A total of 9 cohort studies involving 1,147,473 patients were included in the analysis. The pooled OR was 0.76 (95% CI = 0.64-0.90). The Cochran Q test and I² test indicated only mild heterogeneity (P = 0.12, I² = 38%). In the subgroup analyses, the pooled OR was 0.67 (95% CI = 0.54-0.82) for North America. In the subgroup analyses by mean follow-up time, the pooled OR was 0.46 (95% CI = 0.28-0.74) for less than 5 years. In conclusion, bariatric surgery has a positive effect on pancreatic cancer reduction, especially in North America. This effect may diminish or disappear with time.

Pre-Operative Substance Use Disorder is Associated with Higher Risk of Long-Term Mortality Following Bariatric Surgery

PURPOSE

Metabolic and bariatric surgery (MBS) has been associated with reduced all-cause mortality. While the number of subjects with substance use disorders (SUD) before MBS has been documented, the impact of pre-operative SUD on long-term mortality following MBS is unknown. This study assessed long-term mortality of patients with and without pre-operative SUD who underwent MBS.

MATERIALS AND METHODS

Two statewide databases were used for this study: Utah Bariatric Surgery Registry (UBSR) and the Utah Population Database. Subjects who underwent MBS between 1997 and 2018 were linked to death records (1997-2021) to identify any death and cause for death following MBS. All deaths (internal, external, and unknown reasons), internal deaths, and external deaths were the primary outcomes of the study. External causes of death included death from injury, poisoning, and suicide. Internal causes of death included deaths that were associated with natural causes such as heart disease, cancer, and infections. A total of 17,215 patients were included in the analysis. Cox regression was used to estimate hazard ratios (HR) of controlled covariates, including the pre-operative SUD.

RESULTS

The subjects with pre-operative SUD had a 2.47 times higher risk of death as compared to those without SUD (HR = 2.47, p < 0.01). Those with pre-operative SUD had a higher internal cause of death than those without SUD by 129% (HR = 2.29, p < 0.01) and 216% higher external mortality risk than those without pre-operative SUD (HR = 3.16, p < 0.01).

CONCLUSION

Pre-operative SUD was associated with higher hazards of all-cause, internal cause, and external cause mortality in patients who undergo bariatric surgery.

Systematic Review and Meta-Analysis of the Impact of Bariatric Surgery on Future Cancer Risk

The study aimed to perform a systematic review and meta-analysis of the evidence for the prevention of future cancers following bariatric surgery. A systematic literature search of the Cochrane Library, Embase, Scopus, Web of Science and PubMed databases (2007–2023), Google Scholar and grey literature was conducted. A meta-analysis was performed using the inverse variance method and random effects model. Thirty-two studies involving patients with obesity who received bariatric surgery and control patients who were managed with conventional treatment were included. The meta-analysis suggested bariatric surgery was associated with a reduced overall incidence of cancer (RR 0.62, 95% CI 0.46–0.84, p < 0.002), obesity-related cancer (RR 0.59, 95% CI 0.39–0.90, p = 0.01) and cancer-associated mortality (RR 0.51, 95% CI 0.42–0.62, p < 0.00001). In specific cancers, bariatric surgery was associated with reduction in the future incidence of hepatocellular carcinoma (RR 0.35, 95% CI 0.22–0.55, p < 0.00001), colorectal cancer (RR 0.63, CI 0.50–0.81, p = 0.0002), pancreatic cancer (RR 0.52, 95% CI 0.29–0.93, p = 0.03) and gallbladder cancer (RR 0.41, 95% CI 0.18–0.96, p = 0.04), as well as female specific cancers, including breast cancer (RR 0.56, 95% CI 0.44–0.71, p < 0.00001), endometrial cancer (RR 0.38, 95% CI 0.26–0.55, p < 0.00001) and ovarian cancer (RR 0.45, 95% CI 0.31–0.64, p < 0.0001). There was no significant reduction in the incidence of oesophageal, gastric, thyroid, kidney, prostate cancer or multiple myeloma after bariatric surgery as compared to patients with morbid obesity who did not have bariatric surgery. Obesity-associated carcinogenesis is closely related to metabolic syndrome; visceral adipose dysfunction; aromatase activity and detrimental cytokine, adipokine and exosomal miRNA release. Bariatric surgery results in long-term weight loss in morbidly obese patients and improves metabolic syndrome. Bariatric surgery may decrease future overall cancer incidence and mortality, including the incidence of seven obesity-related cancers.

The Protective Effect of Bariatric Surgery on the Development of Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Obesity is a known risk factor for developing colorectal cancer (CRC) and is associated with the formation of precancerous colonic adenomas. Bariatric surgery (BRS) is considered to reduce the cancer risk in morbidly obese patients. However, the currently available literature yields contradicting results regarding the impact of bariatric surgery on the incidence of CRC.

METHODS

A systematic literature search of the Medline, Embase, CENTRAL, CINAHL, Web of Science, and clinicaltrials.gov databases was undertaken following the PRISMA guidelines. A random effects model was selected.

RESULTS

Twelve retrospective cohort studies, incorporating a total of 6,279,722 patients, were eligible for inclusion in the final quantitative analysis. Eight studies originated from North America, while four reported on European patients. Patients in the Bariatric Surgery group exhibited a significantly reduced risk for developing colorectal cancer (RR 0.56, 95% CI 0.4-0.8, p < 0.001), while sleeve gastrectomy was found to be significantly associated with a smaller incidence of CRC (RR 0.55, 95% CI 0.36-0.83, p < 0.001), and gastric bypass and banding did not.

CONCLUSIONS

A significant protective effect of BRS against the development of CRC is implied. In the present analysis, the incidence rate of colorectal cancer was approximately halved amongst the obese individuals that were operated on.

What is currently known about the association between bariatric surgery and cancer

BACKGROUND

Obesity increases the risk of multiple cancers.

OBJECTIVE

The purpose of this manuscript is to review the high-quality studies that have provided the most compelling evidence around the association between bariatric surgery and cancer risk.

SETTING

Literature review.

METHODS

The literature was reviewed for large high quality observational studies with well matched controls. Identified studies were summarized in this review.

RESULTS

Four large cohort studies were identified and summarized including the Swedish Obese Subjects study, the Utah cohorts, the Kaiser Permanente studies and the SPLENDID study. All four cohorts demonstrated a strong association between bariatric surgery and a reduction in cancer risk. Two of the cohorts showed a reduction in cancer related mortality, and two of the cohorts found a dose-response between amount of weight loss following bariatric surgery and cancer risk.

CONCLUSIONS

The evidence that bariatric surgery is associated with a reduced risk of cancer is compelling.

Long-term all-cause and cause-specific mortality for four bariatric surgery procedures

OBJECTIVE

This retrospective study incorporated long-term mortality results after different bariatric surgery procedures and for multiple age at surgery groups.

METHODS

Participants with bariatric surgery (surgery) and without (non-surgery) were matched (1:1) for age, sex, BMI, and surgery date with a driver license application/renewal date. Mortality rates were compared by Cox regression, stratified by sex, surgery type, and age at surgery.

RESULTS

Participants included 21,837 matched surgery and non-surgery pairs. Follow-up was up to 40 years (mean [SD], 13.2 [9.5] years). All-cause mortality was 16% lower in surgery compared with non-surgery groups (hazard ratio, 0.84; 95% CI: 0.79-0.90; p < 0.001). Significantly lower mortality after bariatric surgery was observed for both females and males. Mortality after surgery versus non-surgery decreased significantly by 29%, 43%, and 72% for cardiovascular disease, cancer, and diabetes, respectively. The hazard ratio for suicide was 2.4 times higher in surgery compared with non-surgery participants (95% CI: 1.57-3.68; p < 0.001), primarily in participants with ages at surgery between 18 and 34 years.

CONCLUSIONS

Reduced all-cause mortality was durable for multiple decades, for multiple bariatric surgical procedures, for females and males, and for greater than age 34 years at surgery. Rate of death from suicide was significantly higher in surgery versus non-surgery participants only in the youngest age at surgery participants.

Obesity, diabetes mellitus, and pancreatic carcinogenesis: Correlations, prevention, and diagnostic implications

The prevalence of obesity, diabetes mellitus (DM), and pancreatic cancer (PC) has been consistently increasing in the last two decades worldwide. Sharing various influential risk factors in genetics and environmental inducers in pathogenesis, the close correlations of these three diseases have been demonstrated in plenty of clinical studies using multiple parameters among different populations. On the contrary, most measures aimed to manage and treat obesity and DM effectively reduce the risk and prevent PC occurrence, yet certain drugs can inversely promote pancreatic carcinogenesis instead. Most importantly, an elevation of blood glucose with or without a reduction in body weight, along with other potential tools, may provide valuable clues for detecting PC at an early stage in patients with obesity and DM, favoring a timely intervention and prolonging survival. Herein, the epidemiological and etiological correlations among these three diseases and the supporting clinical evidence of their connections are first summarized to favor a better and more thorough understanding of obesity- and DM-related pancreatic carcinogenesis. After comparing the distinct impacts of different weight-lowering and anti-diabetic treatments on the risk of PC, the possible diagnostic implications of hyperglycemia and weight loss in PC screening are also addressed in detail.

Risk of non-hormonal cancer after bariatric surgery: meta-analysis of retrospective observational studies

BACKGROUND

Obesity is associated with an increased incidence of at least 13 types of cancer. Although bariatric surgery has been associated with a reduced risk of hormonal cancers, data for non-hormonal cancers are scarce. The aim of this study was to evaluate the effect of bariatric surgery on the incidence of non-hormonal cancers.

METHODS

Cochrane, Embase, PubMed, Scopus, and Web of Science were searched for articles between 1984 and 2018, following the PRISMA system. Meta-analysis was conducted using a random-effect model with subgroup analysis by procedure and cancer type.

RESULTS

From 2526 studies screened, 15 were included. There were a total of 18 583 477 patients, 947 787 in the bariatric group and 17 635 690 in the control group. In comparison to the non-surgical group, the bariatric group had a lower incidence of cancer (OR .65 (95 per cent c.i. 0.53 to 0.80); P < 0.002). In the subgroup analysis, Roux-en-Y gastric bypass and sleeve gastrectomy were associated with decreased risk of developing cancer, while no difference was observed with adjustable gastric banding. When evaluated by cancer type, liver (OR 0.417 (95 per cent c.i. 0.323 to 0.538)), colorectal (OR 0.64 (95 per cent c.i. 0.49 to 0.84)), kidney and urinary tract cancer (OR 0.77 (95 per cent c.i. 0.72 to 0.83)), oesophageal (OR 0.60 (95 per cent c.i. 0.43 to 0.85)), and lung cancer (OR 0.796 (95 per cent c.i. 0.45 to 0.80)) also presented a lower cancer incidence in the bariatric group.

CONCLUSION

Bariatric surgery is related to an almost 50 per cent reduction in the risk of non-hormonal cancers.

Obesity and breast cancer

The paper presents an analysis of the latest literature data on the problem of obesity and breast cancer (BC). This review presents modern approaches to the diagnosis of BC in obese patients, new molecular methods of breast imaging,  analyzes the features of the course of BC with obesity depending on menstrual status, molecular biological subtypes of the tumor, the mechanisms of the development of BC against the background of obesity.

Gastric Pouch Gastrointestinal Stromal Tumour Post-Roux-en-Y Gastric Bypass: A First Reported Case

Gastric gastrointestinal stromal tumour is an extremely rare condition to occur after bariatric surgery. To the authors’ knowledge, only two cases of gastric gastrointestinal stromal tumours after Roux-en-Y gastric bypass have been reported in the medical literature, both occurring in the excluded gastric remnant. Herein, the authors report the third case of gastric gastrointestinal stromal tumour post-Roux-en-Y gastric bypass, and the first case to occur in the gastric pouch, which was managed surgically by laparoscopic resection. From here, combining the observations of clinicians treating and following up patients post-bariatric surgery in an international database will be beneficial to patients, and aid in development of surveillance guidelines.

[Obesity from the Perspective of Surgical Oncology]

Up to 40% of all adults worldwide are overweight or obese. Besides the established obesity-related comorbidities, such as type 2 diabetes mellitus, hypertension or NAFLD (non-alcoholic fatty liver disease), the focus of interest is shifting towards the influence of increased body weight as a risk factor for the development of malignant diseases. For more than 20 different types of malignancies, interactions between increased body weight and cancer risk have been established. Pathophysiological influences of obesity on carcinogenesis are diverse, including factors such as chronic inflammation, hyperinsulinaemia and insulin resistance, various changes in growth factor and changes in sex hormones. In cohorts of visceral oncology patients, malignancies such as colorectal carcinomas, hepatocellular carcinomas, adenocarcinomas of the pancreas, oesophageal and gastric carcinomas are also linked to an increased disease risk with increasing body weight. Since obesity must be considered a preventable or at least treatable cause of cancer, this review examines the influence of obesity in the field of visceral oncology, examining the effects of obesity on tumour prevalence, prevention and diagnostic testing, as well as its influence on treatment and prognosis. Furthermore, this review explores the current evidence on the influence of bariatric surgery on the prevalence of these obesity associated tumours. For example, in the case of colorectal carcinomas, the evidence base following bariatric surgery is mixed, painting an inhomogeneous picture. On the other hand, significantly lower prevalence of pancreatic adenocarcinoma and hepatocellular carcinomas is to be noted. The latter effect can be explained by the decrease in non-alcoholic fatty liver disease (NAFLD) associated with weight loss. Despite the justified concern that bariatric procedures (especially gastric sleeve resection) lead to increased prevalence of malignancies of the oesophageal junction, the currently available epidemiological data does not seem to identify a relevant increase in the incidence of these malignancies.

Body fatness associations with cancer: evidence from recent epidemiological studies and future directions

This narrative review highlights current evidence linking greater body fatness to risk of various cancers, with focus on evidence from recent large cohort studies and pooled analyses of cohort studies as well as Mendelian randomization studies (which utilized genetic variants associated with body mass index to debrief the causal effect of higher body fatness on cancer risk). This review also provides insights into the biological mechanisms underpinning the associations. Data from both observational and Mendelian randomization studies support the associations of higher body mass index with increased risk of many cancers with the strongest evidence for digestive system cancers, including esophageal, stomach, colorectal, liver, gallbladder, and pancreatic cancer, as well as kidney, endometrial, and ovarian (weak association) cancer. Evidence from observational studies suggests that greater body fatness has contrasting effects on breast cancer risk depending on menopausal status and on prostate cancer risk depending on disease stage. Experimental and Mendelian randomization studies indicate that adiponectin, insulin, and sex hormone pathways play an important role in mediating the link between body fatness and cancer risk. The possible role of specific factors and pathways, such as other adipocytokines and hormones and the gut microbiome in mediating the associations between greater body fatness and cancer risk is yet uncertain and needs investigation in future studies. With rising prevalence of overweight and obesity worldwide, the proportion of cancer caused by excess body fatness is expected to increase. There is thus an urgent need to identify efficient ways at the individual and societal level to improve diet and physical activity patterns to reduce the burden of obesity and accompanying comorbidities, including cancer.

Bariatric surgery reduces the risk of pancreatic cancer in individuals with obesity before the age of 50 years: A nationwide administrative data study in France

BACKGROUND

Obesity is a well-established risk factor for pancreatic cancer. Bariatric surgery has demonstrated superior results in terms of weight loss and obesity-related comorbidities compared to medical and behavioral treatments. The aim of this study is to evaluate the effect of bariatric surgery on pancreatic cancer incidence in individuals with obesity.

METHOD

Individuals with a diagnosis of obesity were retrieved from the French national hospital discharge database. We conducted a cohort study comparing the risk to develop pancreatic cancer in individuals with obesity with and without history of bariatric surgery; the inverse probability of treatment weighting (IPTW) method was performed to assess the uncertainty around the results. Moreover, a subgroup analysis according to age at the time of bariatric surgery was performed to study its impact on the risk of pancreatic cancer. Finally, possible differences depending on the type of bariatric procedure (sleeve gastrectomy vs Roux-en-Y gastric bypass) were also explored.

RESULTS

160,129 (Bariatric Surgery group) and 1,263,804 (control group) patients with 5.2 ± 1.9 and 6.0 ± 1.9 years of follow-up respectively were included. A significant reduced risk to develop pancreatic cancer during follow-up was identified for the bariatric surgery group in the overall population (HR: 0.567). However, this reduced risk was only observed in the 18-50 years group. These results were furtherly confirmed after IPTW analysis. No difference was found between different bariatric procedures.

CONCLUSION

Bariatric surgery has a protective effect against pancreatic cancer in the 18-50 years population. High-quality prospective studies are needed to confirm these results.

The global burden and temporal trend of cancer attributable to high body mass index: Estimates from the Global Burden of Disease Study 2019

Objective

The purpose of the study was to describe the burden and temporal trend of cancer attributable to high body mass index (BMI), with major patterns highlighted by sex, Socio-demographic Index (SDI), and geographical region.

Methods

This population-based observational study collected epidemiological data on cancer attributable to high BMI from the Global Burden of Diseases (GBD) 2019. The obtained data included deaths, disability-adjusted life-years (DALYs), and their age-standardized rates at the global, gender, SDI, regional, and country levels. The trend magnitudes and directions over time for mortality were analyzed. The associations between SDI and burden of cancer attributable to high BMI were also evaluated by Pearson correlation analysis.

Results

Worldwide, 462.55 thousand deaths and 11.18 million DALYs of cancer were related to high BMI in 2019, and both have more than doubled since 1990. An annual 0.6% increase was observed for the age-standardized mortality rate (ASMR), and the rate of increase slowed after 2000. In general, the burden of cancer attributable to high BMI was heavier in regions with higher SDI levels, whereas the increase slowed down or even showed a decreasing trend in the recent years. In contrast, in regions with lower SDI levels, although the baseline burden of cancer attributable to high BMI was relatively low, both the numbers and rates of deaths and DALYs showed a significantly increasing trend and may not stop increasing for a period of time. The trend and magnitude of high BMI-related cancer burden varied substantially in different anatomical sites. The leading three cancers of DALYs attributable to high BMI in 2019 were esophageal, colorectal, and liver cancer.

Conclusion

The high BMI-related burden of cancers is worsening, particularly in developing countries. Concerted action should be suggested to increase awareness of the harmful effects of high BMI and decrease the burden of disease attributable to high BMI, including cancer.

Clinical interventions to break the obesity and cancer link: a narrative review

Excess body weight is a significant risk factor for the development and recurrence of many types of cancer. Patients with a history or current diagnosis of cancer who are overweight or have obesity have an increased risk of cancer treatment-related morbidity, recurrence, and decreased quality of life. Weight loss and maintenance of a healthy body weight may reduce cancer morbidity and recurrence in cancer survivors. While guidelines for cancer survivorship elaborate sufficiently on lifestyle interventions, little guidance is provided when considering additional therapies like anti-obesity pharmacotherapy or bariatric surgery for weight loss. This review will highlight and address current recommendations and feasible interventions that clinicians may consider to further reduce the incidence and recurrence of cancer in patients with obesity.

Association of Bariatric Surgery With Cancer Risk and Mortality in Adults With Obesity

IMPORTANCE

Obesity increases the incidence and mortality from some types of cancer, but it remains uncertain whether intentional weight loss can decrease this risk.

OBJECTIVE

To investigate whether bariatric surgery is associated with lower cancer risk and mortality in patients with obesity.

DESIGN, SETTING, AND PARTICIPANTS

In the SPLENDID (Surgical Procedures and Long-term Effectiveness in Neoplastic Disease Incidence and Death) matched cohort study, adult patients with a body mass index of 35 or greater who underwent bariatric surgery at a US health system between 2004 and 2017 were included. Patients who underwent bariatric surgery were matched 1:5 to patients who did not undergo surgery for their obesity, resulting in a total of 30 318 patients. Follow-up ended in February 2021.

EXPOSURES

Bariatric surgery (n = 5053), including Roux-en-Y gastric bypass and sleeve gastrectomy, vs nonsurgical care (n = 25 265).

MAIN OUTCOMES AND MEASURES

Multivariable Cox regression analysis estimated time to incident obesity-associated cancer (a composite of 13 cancer types as the primary end point) and cancer-related mortality.

RESULTS

The study included 30 318 patients (median age, 46 years; median body mass index, 45; 77% female; and 73% White) with a median follow-up of 6.1 years (IQR, 3.8-8.9 years). The mean between-group difference in body weight at 10 years was 24.8 kg (95% CI, 24.6-25.1 kg) or a 19.2% (95% CI, 19.1%-19.4%) greater weight loss in the bariatric surgery group. During follow-up, 96 patients in the bariatric surgery group and 780 patients in the nonsurgical control group had an incident obesity-associated cancer (incidence rate of 3.0 events vs 4.6 events, respectively, per 1000 person-years). The cumulative incidence of the primary end point at 10 years was 2.9% (95% CI, 2.2%-3.6%) in the bariatric surgery group and 4.9% (95% CI, 4.5%-5.3%) in the nonsurgical control group (absolute risk difference, 2.0% [95% CI, 1.2%-2.7%]; adjusted hazard ratio, 0.68 [95% CI, 0.53-0.87], P = .002). Cancer-related mortality occurred in 21 patients in the bariatric surgery group and 205 patients in the nonsurgical control group (incidence rate of 0.6 events vs 1.2 events, respectively, per 1000 person-years). The cumulative incidence of cancer-related mortality at 10 years was 0.8% (95% CI, 0.4%-1.2%) in the bariatric surgery group and 1.4% (95% CI, 1.1%-1.6%) in the nonsurgical control group (absolute risk difference, 0.6% [95% CI, 0.1%-1.0%]; adjusted hazard ratio, 0.52 [95% CI, 0.31-0.88], P = .01).

CONCLUSIONS AND RELEVANCE

Among adults with obesity, bariatric surgery compared with no surgery was associated with a significantly lower incidence of obesity-associated cancer and cancer-related mortality.

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.

Obesity and Pancreatic Cancer: Recent Progress in Epidemiology, Mechanisms and Bariatric Surgery

More than 30% of people in the United States (US) are classified as obese, and over 50% are considered significantly overweight. Importantly, obesity is a risk factor not only for the development of metabolic syndrome but also for many cancers, including pancreatic ductal adenocarcinoma (PDAC). PDAC is the third leading cause of cancer-related death, and 5-year survival of PDAC remains around 9% in the U.S. Obesity is a known risk factor for PDAC. Metabolic control and bariatric surgery, which is an effective treatment for severe obesity and allows massive weight loss, have been shown to reduce the risk of PDAC. It is therefore clear that elucidating the connection between obesity and PDAC is important for the identification of a novel marker and/or intervention point for obesity-related PDAC risk. In this review, we discussed recent progress in obesity-related PDAC in epidemiology, mechanisms, and potential cancer prevention effects of interventions, including bariatric surgery with preclinical and clinical studies.

Effect of bariatric surgery on cancer risk: results from an emulated target trial using population-based data

BACKGROUND

The impact of weight loss induced by bariatric surgery on cancer occurrence is controversial. To study the causal effect of bariatric surgery on cancer risk from an observational database, a target-trial emulation technique was used to mimic an RCT.

METHODS

Data on patients admitted between 2010 and 2019 with a diagnosis of obesity were extracted from a national hospital discharge database. Criteria for inclusion included eligibility criteria for bariatric surgery and the absence of cancer in the 2 years following inclusion. The intervention arms were bariatric surgery versus no surgery. Outcomes were the occurrence of any cancer and obesity-related cancer; cancers not related to obesity were used as negative controls.

RESULTS

A total of 1 140 347 patients eligible for bariatric surgery were included in the study. Some 288 604 patients (25.3 per cent) underwent bariatric surgery. A total of 48 411 cancers were identified, including 4483 in surgical patients and 43 928 among patients who did not receive bariatric surgery. Bariatric surgery was associated with a decrease in the risk of obesity-related cancer (hazard ratio (HR) 0.89, 95 per cent c.i. 0.83 to 0.95), whereas no significant effect of surgery was identified with regard to cancers not related to obesity (HR 0.96, 0.91 to 1.01).

CONCLUSION

When emulating a target trial from observational data, a reduction of 11 per cent in obesity-related cancer was found after bariatric surgery.

Benefits of weight loss of 10% or more in patients with overweight or obesity: A review

OBJECTIVE

Modest weight loss (5%-10%) is clinically meaningful in patients with overweight or obesity. However, greater weight loss may be required to achieve improvements in or remission of certain weight-related complications. Therefore, this study reviewed the effect of large weight loss (≥10%). Most studies reporting large weight loss and relevant outcomes used bariatric surgery or lifestyle modifications.

RESULTS

Benefits of large weight loss were observed in patients with various overweight- or obesity-related complications, including improvements in comorbidities such as type 2 diabetes and hypertension. Improvements in glucose metabolism and cardiovascular risk factors were observed in patients who achieved large weight loss through lifestyle interventions or pharmacotherapy (phentermine/topiramate 15/92 mg once daily or subcutaneous semaglutide 2.4 mg once weekly). Other benefits associated with large weight loss included reduced cancer risk and improvements in knee osteoarthritis, sleep apnea, fertility-related end points, and health-related quality of life. While costly, bariatric surgery is currently the most cost-effective intervention, although most weight-management programs are deemed cost-effective.

CONCLUSIONS

Overall, large weight loss has a major beneficial impact on overweight- and obesity-related complications. Large weight loss should be the main treatment target when modest weight loss has had insufficient effects on obesity-related complications and for patients with severe obesity.

Renal Cell Cancer and Obesity

Cancers are a frequent cause of morbidity and mortality. There are many risk factors for tumours, including advanced age, personal or family history of cancer, some types of viral infections, exposure to radiation and some chemicals, smoking and alcohol consumption, as well as obesity. Increasing evidence suggest the role of obesity in the initiation and progression of various cancers, including renal cell carcinoma. Since tumours require energy for their uncontrollable growth, it appears plausible that their initiation and development is associated with the dysregulation of cells metabolism. Thus, any state characterised by an intake of excessive energy and nutrients may favour the development of various cancers. There are many factors that promote the development of renal cell carcinoma, including hypoxia, inflammation, insulin resistance, excessive adipose tissue and adipokines and others. There are also many obesity-related alterations in genes expression, including DNA methylation, single nucleotide polymorphisms, histone modification and miRNAs that can promote renal carcinogenesis. This review focuses on the impact of obesity on the risk of renal cancers development, their aggressiveness and patients’ survival.

Obesity and breast cancer: Preventive and therapeutic possibilities for bariatric surgery

Breast cancer is the most common and second deadliest malignancy in women. With rising obesity rates and building evidence for a strong association with obesity, the incidence of breast cancer can be expected to increase. Weight loss reduces breast cancer risk, the mechanisms of which are still poorly understood. As an effective therapy for obesity, bariatric surgery may be a powerful tool in breast cancer prevention and treatment. This review details the potential physiologic mechanisms that may underlie this association, as well as recently published studies that reinforce the link between bariatric surgery and a reduction in incident breast cancer. The use of bariatric surgery as an adjunct therapy in endometrial cancer also raises the potential for similar use in select breast cancer patients. Despite the expanding potential applications of bariatric surgery in this field, publications to date have been strictly observational, highlighting a need for future clinical trials.

The Relationship Between Diabetes Mellitus and Cancers and Its Underlying Mechanisms

Epidemiological studies suggest associations between diabetes mellitus and some cancers. The risk of a number of cancers appears to be increased in diabetes mellitus. On the other hand, some cancer and cancer therapies could lead to diabetes mellitus. Genetic factors, obesity, inflammation, oxidative stress, hyperglycemia, hyperinsulinemia, cancer therapies, insulin and some oral hypoglycemic drugs appear to play a role in the crosstalk between diabetes mellitus and cancers. This review summarized the associations between various types of diabetes and cancers and updated available evidence of underlying mechanisms between diabetes and cancers.

Association of Bariatric Surgery With Cancer Incidence in Patients With Obesity and Diabetes: Long-term Results From the Swedish Obese Subjects Study

OBJECTIVE

Obesity and type 2 diabetes are associated with serious adverse health effects, including cancer. Although bariatric surgery has been shown to reduce cancer risk in patients with obesity, the effect of bariatric surgery on cancer risk in patients with obesity and diabetes is less studied. We therefore examined the long-term incidence of cancer after bariatric surgery and usual care in patients with obesity and diabetes in the matched prospective Swedish Obese Subjects (SOS) study.

RESEARCH DESIGN AND METHODS

The SOS study examines long-term outcomes following bariatric surgery or usual care. The current analysis includes 701 patients with obesity and type 2 diabetes at baseline, 393 of whom underwent bariatric surgery and 308 who received conventional obesity treatment. Information on cancer events was obtained from the Swedish National Cancer Register. Median follow-up time was 21.3 years (interquartile range 17.6-24.8 years, maximum 30.7 years).

RESULTS

During follow-up, the incidence rate for first-time cancer was 9.1 per 1,000 person-years (95% CI 7.2-11.5) in patients with obesity and diabetes treated with bariatric surgery and 14.1 per 1,000 person-years (95% CI 11.2-17.7) in patients treated with usual obesity care (adjusted hazard ratio 0.63 [95% CI 0.44-0.89], P = 0.008). Moreover, surgery was associated with reduced cancer incidence in women (0.58 [0.38-0.90], P = 0.016), although the sex-treatment interaction was nonsignificant (P = 0.630). In addition, diabetes remission at the 10-year follow-up was associated with reduced cancer incidence (0.40 [0.22-0.74], P = 0.003).

CONCLUSIONS

These results suggest that bariatric surgery prevents cancer in patients with obesity and diabetes and that durable diabetes remission is associated with reduced cancer risk.

Long-Term Results of Single-Anastomosis Duodeno-ileal Bypass with Sleeve Gastrectomy (SADI-S)

BACKGROUND

Single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) is a simplification of the duodenal switch (DS) in which the alimentary limb is eliminated, and the common channel is lengthened from 200 to 300 cm. Short-term results have demonstrated that SADI-S is safe and reproducible and that weight loss and comorbidities resolution are comparable to biliopancreatic diversion or DS.

OBJECTIVE

To analyze the long-term outcomes of SADI-S.

METHODS

From May 2007 to December 2015, 164 patients were consecutively submitted to a one-step SADI-S. The mean age was 47 years, and the mean body mass index (BMI) was 45.8 kg/m². A total of 101 patients had type 2 diabetes, 91 arterial hypertension, 81 obstructive apnea, and 118 dyslipidemia. Limb length was 200 cm in 50 cases, 250 cm in 99, and 300 cm in 15.

RESULTS

There was no mortality. One patient had a gastric leak, and 2 patients had an anastomotic leak. A total of 25% of the patients were lost to follow-up at 10 years. Excess weight loss and total weight loss were 87% and 38% at 5 years and 80% and 34% at 10 years. A total of 12 patients were submitted to revisional surgery for hypoproteinemia. Preoperatively 41 diabetics were under insulin treatment; at 5 years, 7 remained with insulin and 12 at 10 years. Mean glycemia was 104 mg/dL at 5 years and 118 mg/dL at 10 years. Mean HbA1c was 5.51% at 5 years and 5.86 at 10 years.

CONCLUSION

In the long term, SADI-S offers satisfactory weight loss and comorbidities resolution.