Cancer risk reduction in severely obese patients with NAFLD after bariatric surgery

By Rebecca Jenkins
Bariatric surgery reduces the risk of cancer in severely obese adults with nonalcoholic fatty liver disease (NAFLD), research shows for the first time.

The retrospective cohort study included 98,090 patients aged 18 to 64 years newly diagnosed with severe obesity and NAFLD between 2007 and 2017, of whom 33,435 (34.15%) went on to receive bariatric surgery.

In those without surgery, 1898 incident cases of cancer occurred over 115,890.11 person-years of follow up, compared with 925 cancer cases among surgery patients over 67,389.82 person-years of follow up.

There was an 18% risk reduction for all types of cancer, which rose to a 25% risk reduction for obesity-specific cancers, the authors reported in Gastroenterology.

‘The adjusted risks of any cancer and obesity-related cancer were significantly lower in cirrhotic versus noncirrhotic patients who underwent surgery,’ the researchers added.

When looking at obesity-specific cancers, bariatric surgery was associated with significant risk reductions for colorectal, pancreatic, endometrial, thyroid cancers; hepatocellular carcinoma; and multiple myeloma, the study found.

‘Understanding the connection between NAFLD and cancer may identify new targets and treatments, such as antidiabetic-, satiety-, or [glucagon-like peptide-1]-based medications, for chemoprevention in NAFLD/[nonalcoholic steatohepatitis],’ the researchers wrote.

‘Though bariatric surgery is a more aggressive approach than lifestyle modifications, surgery may provide additional benefits, such as improved quality of life and decreased long-term healthcare costs.’

Professor John Dixon, Adjunct Professor at the Iverson Health Innovation Research Institute at Swinburne University of Technology, Melbourne, and clinical obesity expert, welcomed the study, saying it added to previous research finding bariatric surgery reduced cancer and cardiovascular mortality as well as risks and complications associated with type 2 diabetes.

‘There are also sustained improvements in health-related quality of life, and health economic analysis indicated surgery is cost-effective and, in some situations, saves on long-term health costs.’

However, Professor Dixon warned that despite the mounting evidence to support the benefits of bariatric surgery, the procedure remained underfunded and difficult for public patients to access in Australia.

‘Currently, our health services are structured to make those living with obesity sick. This is yet another study that will fall on deaf ears,’ he told Medicine Today.

‘Weight stigma, bias and discrimination are systemic in our society and throughout our healthcare services,’ he noted.

‘Until we as a nation understand and manage this chronic progressive disease as we do cancer, heart disease and diabetes, the current negligent approach will continue. Shaming and blaming those living with obesity and its complications exacerbates their condition through internalised stigma.’
Gastroenterology 2021; doi: https://doi.org/10.1053/j.gastro.2021.03.021.