Association of Bariatric Surgery and Risk of Cancer in Patients With Morbid Obesity

Syed I. Khalid, MD; Samantha Maasarani, MD, MPH; Julia Wiegmann, MSCR; Aaron L. Wiegmann, MD, MS; Adan Z. Becerra, PhD; Philip Omotosho, MD; Alfonso Torquati, MD


Annals of Surgery. 2022;275(1):1-6. 

In This Article

Abstract and Introduction


Objective: This study investigates the rates of obesity-related cancers in patients undergoing vertical sleeve gastrectomy (VSG), Roux-en-Y gastric bypass (RYGB), or no surgical intervention.

Summary Background Data: Obesity has been previously associated with increased rates of cancers; however, weight loss surgeries have not been explored to demonstrate their potential risk reduction impact.

Methods: Patients meeting bariatric eligibility criteria between January 2010 and December 2018 were identified. Exact 1:1:1 matching based on baseline patient demographics and comorbidities was used to create 3 groups with identical covariates: patients undergoing VSG, RYGB, and no surgery.

Results: A total of 28, bariatric-eligible patients equally split into patients undergoing VSG (n = 9636, 33.3%), RYGB (n = 9636, 33.3%), and those with no surgical intervention (n = 9636, 33.3%). Bariatric-eligible patients that did not undergo surgical intervention had significantly higher rates and odds of developing numerous cancer types included in our study when compared to either surgical cohorts, with any cancer type (4.61%), uterine (0.86%), colorectal (0.57%), and lung cancers (0.50%) being most common. Individuals undergoing RYGB were significantly less likely to develop colorectal cancer compared to patients without any surgical intervention [odds ratio (OR) 0.47, 95% confidence interval (CI) 0.30–0.75]. Additionally, those undergoing VSG were significantly less likely to develop lung cancer than the bariatric eligible no surgery cohort (OR 0.42, 95% CI 0.25–0.70).

Conclusion: Postoperative rates of any cancer type, lung, ovarian, and uterine cancer were significantly lower in obese patients undergoing either vertical sleeve gastrectomy (VSG) or RYGB compared to bariatric-eligible patients without any surgical intervention.


The national obesity epidemic in the United States is well documented with >30% of the adult population being considered obese, defined as a body mass index (BMI) of 30 kg/m2 or more, and almost 10% of adults classified as severe obesity, defined as BMI of ≥40 kg/m2.[1,2] The prevalence of adult obesity and severe obesity is predicted to increase nationwide, with projections estimating that 1 in 2 adults and 1 in 4 adults will be classified as obese and severely obese by 2030.[3]

The sequelae of obesity are estimated to reduce one's life expectancy by 5 to 20 years[4] and are associated with an increased incidence of several cancer types.[5–21] Obesity accounts for approximately 4% of all male and 7% of all female cancers.[22] Furthermore, it is estimated to account for 14% in men and 20% in women of all-cancer related deaths in the United States.[7]

Over the past few years, bariatric surgery has increased in popularity with approximately 135,432 vertical sleeve gastrectomy (VSG) and 40,584 Roux-en-Y gastric bypass (RYGB) procedures performed in 2017.[23] Presently, bariatric surgery has been proven to be the most effective treatment to induce and maintain weight loss long-term.[24–31] Additionally, bariatric surgery has been shown to improve mortality, including cancer-related deaths,[32–34] and morbidity by mitigating obesity-related diseases, such as diabetes and hypertension.[25,29–31,35]

However, previous literature shows conflicting results regarding the incidence of specific cancer types following bariatric surgery.[10,36–38] Furthermore, there is a lack of high-quality studies examining VSG versus RYGB procedures' likelihood of augmenting future obesity and non–obesity-related cancer development given the large weight reductions associated with bariatric surgery. Therefore, the primary objective of this study aims to investigate the rates of both obesity-related and non–obesity-related cancers in bariatric-eligible patients undergoing VSG, RYGB, or no surgical intervention. Secondarily, we sought to analyze and compare the impact, if any, of VSG versus RYGB procedures had on cancer development.