Metabolic surgery and cancer: protective effects of bariatric procedures.

Department of Surgery and Cancer, Imperial College London, London, England.
Cancer (Impact Factor: 4.9). 05/2011; 117(9):1788-99. DOI: 10.1002/cncr.25738
Source: PubMed

ABSTRACT The worldwide epidemic of obesity and the global incidence of cancer are both increasing. There is now epidemiological evidence to support a correlation between obesity, weight gain, and some cancers. Metabolic or bariatric surgery can provide sustained weight loss and reduced obesity-related mortality. These procedures can also improve the metabolic profile to decrease cardiovascular risk and resolve diabetes in morbidly obese patients. The operations offer several physiological steps, the so-called BRAVE effects: 1) bile flow alteration, 2) reduction of gastric size, 3) anatomical gut rearrangement and altered flow of nutrients, 4) vagal manipulation and 5) enteric gut hormone modulation. Metabolic operations are also associated with a significant reduction of cancer incidence and mortality. The cancer-protective role of metabolic surgery is strongest for female obesity-related tumors; however, the underlying mechanisms may involve both weight-dependent and weight-independent effects. These include the improvement of insulin resistance with attenuation of the metabolic syndrome as well as decreased oxidative stress and inflammation in addition to the beneficial modulation of sex steroids, gut hormones, cellular energetics, immune system, and adipokines. Elucidating the precise metabolic mechanisms of cancer prevention by metabolic surgery can increase our understanding of how obesity, diabetes, and metabolic syndrome are associated with cancer. It may also offer novel treatment strategies in the management of tumor generation and growth.

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Available from: Kamran Ahmed, Oct 08, 2014
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    • "In contrast to reports from large-scale human epidemiological cohorts suggesting a reduced cancer risk following bariatric surgery (Ashrafian et al., 2011a), we have demonstrated increased fecal cytotoxicity in this Wistar rat model following RYGB surgery; which can be associated with increased colonic cancer risk (de Kok and van Maanen, 2000). Two possible explanations for the conflicting RYGB effects between humans and rats include: (i) the rat model is not translational to humans with regard to RYGB surgery, or more controversially that the RYGB surgery increases the cytotoxicity of feces, however human colonocytes, are subject to a high degree of oxidative stress and possess enzymes capable of detoxifying H 2 S and other toxins (Ramasamy et al., 2006), are resistant to this toxicity. "
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