Development of cancer after bariatric surgery

Weight-centric prevention of cancer

Background

The link between excess adiposity and carcinogenesis has been well established for multiple malignancies, and cancer is one of the main contributors to obesity-related mortality. The potential role of different weight-loss interventions on cancer risk modification has been assessed, however, its clinical implications remain to be determined. In this clinical review, we present the data assessing the effect of weight loss interventions on cancer risk.

Methods

In this clinical review, we conducted a comprehensive search of relevant literature using MEDLINE, Embase, Web of Science, and Google Scholar databases for relevant studies from inception to January 20, 2024. In this clinical review, we present systematic reviews and meta-analysis, randomized clinical trials, and prospective and retrospective observational studies that address the effect of different treatment modalities for obesity in cancer risk. In addition, we incorporate the opinions from experts in the field of obesity medicine and oncology regarding the potential of weight loss as a preventative intervention for cancer.

Results

Intentional weight loss achieved through different modalities has been associated with a reduced cancer incidence. To date, the effect of weight loss on the postmenopausal women population has been more widely studied, with multiple reports indicating a protective effect of weight loss on hormone-dependent malignancies. The effect of bariatric interventions as a protective intervention for cancer has been studied extensively, showing a significant reduction in cancer incidence and mortality, however, data for the effect of bariatric surgery on certain specific types of cancer is conflicting or limited.

Conclusion

Medical nutrition therapy, exercise, antiobesity medication, and bariatric interventions, might lead to a reduction in cancer risk through weight loss-dependent and independent factors. Further evidence is needed to better determine which population might benefit the most, and the amount of weight loss required to provide a clinically significant preventative effect.

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.

Cancer incidence, type, and survival after bariatric surgery

BACKGROUND

Many types of cancer have been found to be associated with being overweight or obese. Literature has demonstrated a reduction in cancer risk in patients who have undergone bariatric surgery.

OBJECTIVES

To compare the incidence and types of new cancer diagnoses, cumulative cancer incidence, cancer risk, and overall survival in patients with obesity who underwent bariatric surgery with that of those who did not.

SETTING

Community-based academic medical center.

METHODS

We retrospectively compared the rates and types of new incident cancers in a bariatric surgery cohort (Bariatric group) with those of a non-surgical cohort (Comparison group). The Comparison group was chosen from patients who had a clinic visit in our health system within 30 days of each bariatric surgical operation and matched on age, sex, and body mass index. Patients who had a cancer diagnosis prior to having bariatric surgery were excluded from the Bariatric group and patients who had a cancer diagnosis prior to the clinic visit on which they were matched were excluded from the Comparison group. Relative risk of cancer by type was calculated. Chi-square and Fisher exact tests were used for categorical data analysis, and Wilcoxon rank-sum for continuous data. The Kaplan Meier estimator with the log-rank test was used to compare overall survival between groups, while competing risks survival analysis with the Gray test for equality was used to compare cancer incidence in the Surgery group with that in the Comparison group.

RESULTS

After matching, the Bariatric group had 1593 patients and the Comparison group had 2156. The Bariatric and Comparison groups had 82 and 222 new incident cancer cases, respectively (P < .001). The 10-year incidence of any new cancer in the Bariatric group was 6.5%, compared with an incidence of 12.1% in the Comparison group (P < .001). Relative risk of cancer in the Bariatric group was lower than that of the Comparison group, with the greatest differences in endometrial (88.8%), kidney (77.4%), thyroid (72.9%), and ductal carcinoma in situ (71.2%) cancers. The 10-year overall survival rate was higher in the Bariatric group than in the Comparison group, 93.3% versus 80.6%, respectively (P < .001).

CONCLUSIONS

Bariatric surgery reduces the risk for developing cancer and offers survival advantage when compared with similar patients who do not undergo bariatric surgery.

Bariatric surgery reduces colorectal cancer incidence in obese individuals: Systematic review and meta-analysis

BACKGROUND

Colorectal cancer ranks third in global cancer prevalence and stands as the second leading cause of cancer-related mortalities. With obesity recognized as a pivotal risk factor for colorectal cancer, the potential protective role of bariatric surgery, especially laparoscopic Roux-en-Y gastric bypass and laparoscopic sleeve gastrectomy, has garnered attention.

AIM

To investigate the Roux-en-Y gastric bypass (RYGB) vs sleeve gastrectomy (SG) effect on colorectal cancer incidence in obese individuals.

METHODS

A systematic review and meta-analysis of the literature was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Seventeen studies with a total of 12497322 patients were included. The primary outcome was the relative risk (RR) of developing colorectal cancer in obese patients who underwent weight loss surgery compared to those who did not. Secondary outcomes included determining the RR for colon and rectal cancer separately and subgroup analyses by gender and type of weight loss surgery.

RESULTS

The meta-analysis revealed a 54% reduction in colorectal cancer risk in morbidly obese patients who underwent bariatric surgery compared to those who did not. A significant 46% reduction in colorectal cancer risk was observed among female patients. However, no significant differences were found in the meta-analysis for various types of bariatric surgery, such as SG and RYGB.

CONCLUSION

This meta-analysis reveals weight loss surgery, regardless of type, reduces colorectal cancer risk, especially in women, as indicated by RR and hazard ratio assessments. Further validation is essential.

Calorie restriction outperforms bariatric surgery in a murine model of obesity and triple-negative breast cancer

Obesity promotes triple-negative breast cancer (TNBC), and effective interventions are urgently needed to break the obesity-TNBC link. Epidemiologic studies indicate that bariatric surgery reduces TNBC risk, while evidence is limited or conflicted for weight loss via low-fat diet (LFD) or calorie restriction (CR). Using a murine model of obesity-driven TNBC, we compared the antitumor effects of vertical sleeve gastrectomy (VSG) with LFD, chronic CR, and intermittent CR. Each intervention generated weight and fat loss and suppressed tumor growth relative to obese mice (greatest suppression with CR). VSG and CR regimens exerted both similar and unique effects, as assessed using multiomics approaches, in reversing obesity-associated transcript, epigenetics, secretome, and microbiota changes and restoring antitumor immunity. Thus, in a murine model of TNBC, bariatric surgery and CR each reverse obesity-driven tumor growth via shared and distinct antitumor mechanisms, and CR is superior to VSG in reversing obesity's procancer effects.

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.

Impacts of bariatric surgery on adverse liver outcomes: a systematic review and meta-analysis

BACKGROUND

Bariatric surgery has been reported to improve degeneration, inflammation, and fibrosis in nonalcoholic fatty liver disease, but the effects of bariatric surgery on the associated clinical outcomes is not known.

OBJECTIVES

This work aimed to assess the impacts of bariatric surgery on adverse liver outcomes in people with obesity.

SETTING

An electronic search was performed on EMBASE, PubMed, and Cochrane Central Register of Controlled Trials (CENTRAL).

METHODS

The primary outcome was the incidence of adverse liver outcomes following bariatric surgery. Liver cancer, cirrhosis, liver transplantation, liver failure, and liver-related mortality were defined as adverse hepatic outcomes.

RESULTS

We analyzed data from 18 studies comprising 16,800,287 post bariatric surgical patients and 10,595,752 control patients. We found that bariatric surgery reduced the risk of adverse liver outcomes in people with obesity (hazard ratio [HR] = .33, 95% confidence interval [CI] = .31-.34; I2 = 98.1%). The subgroup analysis showed that bariatric surgery reduced the risk of nonalcoholic cirrhosis (HR = .07, 95% CI = .06-.08; I2 = 99.3%) and liver cancer (HR = .37, 95% CI = .35-.39; I2 = 97.8%), although bariatric surgery may also increase the risk of postoperative alcoholic cirrhosis (HR = 1.32, 95% CI = 1.35-1.59).

CONCLUSIONS

This systematic review and meta-analysis revealed that bariatric surgery lowered the incidence of adverse hepatic outcomes. However, bariatric surgery may also increase the risk of alcoholic cirrhosis after surgery. Future randomized controlled trials are required to further investigate the effects of bariatric surgery on liver of people with obesity.

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.

The effect of bariatric surgery on reducing the risk of colorectal cancer: a meta-analysis of 3,233,044 patients

BACKGROUND

The published literature presents conflicting results regarding the impact of bariatric surgery on the incidence of colorectal cancer. There are important new studies that have addressed this question with longer follow-up.

OBJECTIVE

To investigate the effect of bariatric surgery on the risk of developing colorectal cancer in patients with obesity.

SETTING

Meta-analysis.

METHODS

PubMed and Scopus were searched for relevant articles. Articles published by November 2021 were retrieved; data were extracted according to the evidence-based PICO (population, intervention, control, outcome) model and analyzed using a random-effects model to estimate the pooled relative risk (RR) and its 95% confidence interval. The heterogeneity of studies was tested and quantified using Cochran's Q.

RESULTS

The initial search yielded 327 articles. After evaluation, 13 studies were analyzed. The thorough evaluation resulted in 13 articles, which were analyzed. A total number of 3,233,044 patients were included in the meta-analysis. The mean time of follow-up was 9.5 ± 7.9 years. The pooled estimate of the adjusted RR was .63 (95% confidence interval, .50-.79). Heterogeneity χ² was 107.96 (df = 12; P < .001; I² = 89%).

CONCLUSION

Patients who underwent bariatric surgery had a 37% reduction in the risk of developing colorectal cancer compared with patients with obesity who had no 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.

Does Bariatric Surgery Reduce the Risk of Colorectal Cancer in Individuals with Morbid Obesity? A Systematic Review and Meta-Analysis

Bariatric surgery has shown to be effective in producing sustained weight loss and the resolution of obesity related medical problems. Recent research focused on the role of obesity and adipose tissue in tumorigenesis, finding a strong crosslink through different mechanisms and highlighting an increase in cancer incidence in individuals with obesity. The aim of this meta-analysis is to find if bariatric surgery reduces the incidence of colorectal cancer in patients with obesity. We performed a meta-analysis including 18 studies (PROSPERO ID: CRD4202235931). Bariatric surgery was found to be significantly protective toward colorectal cancer incidence in individuals with obesity (HR: 0.81, p = 0.0142). The protective effect persisted when considering women (RR: 0.54, p = 0.0014) and men (RR: 0.74, p = 0.2798) separately, although this was not significant for the latter. No difference was found when comparing Roux-en-Y gastric bypass and sleeve gastrectomy. Bariatric surgery reduces the incidence of colorectal cancer in individuals with obesity independently from gender and surgical procedure. Prospective large cohort studies are needed to confirm these findings.

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.

Oesophageal and Gastric Cancer After Bariatric Surgery: an Up-to-Date Systematic Scoping Review of Literature of 324 Cases

BACKGROUND

This review aimed to give an updated overview of the occurrence, diagnosis, treatment and outcome of oesophageal and gastric cancer after bariatric and metabolic surgery (BMS).

METHODS

Two searches were done (one for original studies and one for systematic reviews) using an adapted form of "scoping review methodology". MEDLINE, Embase, CINAHL, Pubmed and the Cochrane Library were searched for studies on patients with either oesophageal or gastric cancer after BMS.

RESULTS

A total of 52 unique studies were included which reported on 324 patients, which included 110 (34%) males and 136 (42%) females. In the remaining 78 patients, gender was not specified. A mean of 62.95 ± 32.75 months was the time from BMS to diagnosis of cancer. Most of the patients had a Roux-en-Y gastric bypass (RYGB) as index bariatric surgical procedure, followed by gastric banding (GB) and sleeve gastrectomy (SG) (respectively, 133 (41.0%) RYGB, 97 (30.0%) GB and 58 (18.0%) SG). Seven cases have been reported after OAGB-MGB (3 in gastric remnant, 4 in oesophagus/gastric pouch). Seventy-seven (24%) had distant metastasis (≥ M1/Mx status). The majority of tumours were adenocarcinoma (n = 208, 87.4%). In the majority of the cases, a surgical approach was preferred with either adjuvant chemo or radiotherapy. In the course of the disease, 122 of 324 patients died (37.8%).

CONCLUSION

To our knowledge, this is the most up-to-date review addressing oesophageal and gastric malignancies after bariatric surgery. Future research should focus to optimise screening for oesophageal and gastric cancer after bariatric surgery.

Gastric adenocarcinoma in the excluded stomach 18 years after bariatric surgery: a case report

Gastric cancer (GC) ranks fourth in overall cancer mortality. Bariatric surgical procedures, especially the gastric bypass surgery (GBS), raise a concern about the risk of GC in the excluded stomach (ES). Diagnosis of GC in the ES is challenging due to anatomical changes and impossibility of endoscopic access to the ES. There are few reports of GC after GBS, and it occurs more in the gastric stump than in the ES. We report a case of a 54-year-old female with GC in the ES 18 years after GBS. The increasing number of GBS and the aggressiveness of the GC show how relevant this case is to emphasize the need to consider this diagnosis in patients who develop upper abdominal symptoms, anemia or weight loss.

Gut microbiota in bariatric surgery

Gut microbes share a symbiotic relationship with humans and perform several metabolic and physiological functions essential for human survival. It has been established in several scientific studies that obesity and other metabolic complications are always associated with disturbed gut microbiota profile, also called gut dysbiosis. In recent years, bariatric surgery has become a treatment of choice for weight loss, and it forms an important part of obesity management strategies across the globe. Interestingly, bariatric surgery has been shown to alter gut microbiota profile and synthesize short-chain fatty acids by gut microbes. In other words, gut microbes play a crucial role in better clinical outcomes associated with bariatric surgery. In addition, gut microbes are important in reducing weight and lowering the adverse events post-bariatric surgery. Therefore, several prebiotics, probiotics and postbiotics are recommended for patients who underwent bariatric surgery procedures for better clinical outcomes. The present review aims to understand the possible association between gut microbes and bariatric surgery and present scientific evidence showing the beneficial role of gut microbes in improving therapeutic outcomes of bariatric surgery.

Esophageal and gastric malignancies after bariatric surgery: a retrospective global study

BACKGROUND

Bariatric surgery can influence the presentation, diagnosis, and management of gastrointestinal cancers. Esophagogastric (EG) malignancies in patients who have had a prior bariatric procedure have not been fully characterized.

OBJECTIVE

To characterize EG malignancies after bariatric procedures.

SETTING

University Hospital, United Kingdom.

METHODS

We performed a retrospective, multicenter observational study of patients with EG malignancies after bariatric surgery to characterize this condition.

RESULTS

This study includes 170 patients from 75 centers in 25 countries who underwent bariatric procedures between 1985 and 2020. At the time of the bariatric procedure, the mean age was 50.2 ± 10 years, and the mean weight 128.8 ± 28.9 kg. Women composed 57.3% (n = 98) of the population. Most (n = 64) patients underwent a Roux-en-Y gastric bypass (RYGB) followed by adjustable gastric band (AGB; n = 46) and sleeve gastrectomy (SG; n = 43). Time to cancer diagnosis after bariatric surgery was 9.5 ± 7.4 years, and mean weight at diagnosis was 87.4 ± 21.9 kg. The time lag was 5.9 ± 4.1 years after SG compared to 9.4 ± 7.1 years after RYGB and 10.5 ± 5.7 years after AGB. One third of patients presented with metastatic disease. The majority of tumors were adenocarcinoma (82.9%). Approximately 1 in 5 patients underwent palliative treatment from the outset. Time from diagnosis to mortality was under 1 year for most patients who died over the intervening period.

CONCLUSION

The Oesophago-Gastric Malignancies After Obesity/Bariatric Surgery study presents the largest series to date of patients developing EG malignancies after bariatric surgery and attempts to characterize this condition.

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.

Bariatric surgery in patients with breast and endometrial cancer in California: population-based prevalence and survival

BACKGROUND

The number of bariatric surgeries performed in the United States has increased substantially since the 1990's. However, the prevalence and prognostic impact of bariatric surgery, or weight loss surgery (WLS), among patients with cancer are not known.

OBJECTIVES

We investigated the population-based prevalence of WLS in women with breast or endometrial cancer and conducted exploratory analysis to examine whether postdiagnosis WLS is associated with survival.

SETTING

Administrative statewide database.

METHODS

WLS records for women with nonmetastasized breast (n = 395,146) or endometrial (n = 69,859) cancer were identified from the 1991-2014 California Cancer Registry data linked with the California Office of Statewide Health Planning and Development database. Characteristics of the patients were examined according to history of WLS. Using body mass index data available since 2011, a retrospective cohort of patients with breast or endometrial cancer and obesity (n = 12,540) was established and followed until 2017 (5% lost to follow-up). Multivariable cause-specific Cox proportional hazards models were used to examine the associations between postdiagnostic WLS and time to death.

RESULTS

WLS records were identified for 2844 (.7%) patients with breast cancer and 1140 (1.6%) patients with endometrial cancer; about half of the surgeries were performed after cancer diagnosis. Postdiagnosis WLS was performed in ∼1% of patients with obesity and was associated with a decreased hazard for death (cause-specific hazard ratio = .37; 95% confidence interval = .014-.99; P = .049), adjusting for age, stage, co-morbidity, race/ethnicity, and socioeconomic status.

CONCLUSION

About 2000 patients with breast or endometrial cancer in California underwent post-diagnosis WLS between 1991 and 2014. Our data support survival benefits of WLS after breast and endometrial cancer diagnosis.

Clinical outcomes of bariatric surgery - Updated evidence

Obesity has grown to become a major health problem over the past few decades. Obesity-related comorbidities, such as diabetes mellitus, hypertension, obstructive sleep apnea, and dyslipidemia, are inextricably linked with increased adverse clinical consequences and mortality. Compared with other strategies for obesity, bariatric surgery is efficient in weight loss and has been proved to exert positive effects on obesity-related risk factors. This broad improvement in risk factors has resulted in substantial remission or reductions of comorbidities and better performance on clinical outcomes, including cardiovascular diseases, cancer, and mortality. With the development of surgical procedures, the safety of bariatric surgery has been validated and the rate of peri-operative death is low all over the world. Nonetheless, surgeons ought to be careful about potential complications, such as nutrition deficiencies, psychological disorders, or new digestive tract tumors after surgery. For patients with obesity, bariatric surgery might be a precious and crucial tool to bring additional benefits including comorbidities protection and life span extension. All patients with obesity should be engaged in a union consultation group to select a suitable treatment.

The Triple Health Threat of Diabetes, Obesity, and Cancer-Epidemiology, Disparities, Mechanisms, and Interventions

Obesity and type 2 diabetes are both chronic, relapsing, progressive diseases that are recognized as risk factors for the development of multiple types of cancer. In a recent symposium titled "Hitting A Triple-Diabetes, Obesity, and the Emerging Links to Cancer Risk," convened by The Obesity Society during ObesityWeek 2019, experts in the field presented the current science and highlighted existing research gaps. Topics included (1) the epidemiology of obesity and diabetes and their links to cancer risk; (2) racial and ethnic differences in obesity, diabetes, and cancer risk; (3) biological mechanisms common to obesity and diabetes that may increase cancer risk; and (4) innovative interventions that can be used to prevent the development of cancers related to obesity and diabetes. This report provides an overview of the symposium and describes key research gaps and pressing questions in need of answers to advance the field. The collective burden of obesity, diabetes, and cancer represents one of the largest public health challenges of the century. Although the symposium was titled "hitting a triple," it was recognized that being able to disrupt the linkages among obesity, diabetes, and cancer would be a "grand slam" for public health and medicine.