Weight loss surgery, specifically gastric bypass, may lower the chances of developing colon cancer in obese individuals.
In a groundbreaking study led by Dr. Rebecca Kesselring and her team at the University Hospital Freiburg, it has been discovered that gastric bypass surgery could potentially reduce the risk of colorectal cancer and almost completely prevent metastases in mice [1]. The research, titled "Metabolic surgery reduces CRC disease progression through circulating bile acid diversion," can be found at www.science.org/doi/10.1126/scitranslmed.ads9705.
The study compared three groups: mice that had lost weight through gastric bypass, weight-reduced animals without surgery, and obese control mice that underwent sham surgery. Interestingly, only the gastric bypass protected against tumors [2].
The key factor in the reduction of colorectal cancer risk by a gastric bypass is the altered composition of bile acids. A gastric bypass operation, as well as directly diverting bile acids into the lower small intestine, has the same protective effect [3]. This change in bile acid composition slows down cell growth, suggesting a potential mechanism for colorectal cancer prevention [4].
In the analysis of 41 patient blood samples, those with high levels of primary bile acids developed new metastases a median of more than a year earlier than those with low levels [5]. This finding aligns with the research, as the gastric bypass surgery led to a reduction in the levels of these harmful bile acids.
The Onkoimmunology research group led by Dr. Kesselring plans to investigate whether the composition of bile acids can be influenced therapeutically without surgery, using specific medications or combined interventions on the stomach and bile duct [6]. The study's findings could potentially lead to new treatments and biomarkers for colorectal cancer risk and metastasis.
With more than 60,000 people in Germany being newly diagnosed with colorectal cancer each year, the implications of this research are significant. Obesity itself nearly doubles the risk of colorectal cancer, and gastric bypass leads to substantial and sustained weight loss, mitigating many of these harmful metabolic and inflammatory conditions contributing to cancer development [7][8].
Gastric bypass surgery, a type of bariatric surgery, is generally associated with a reduced risk of colorectal cancer in individuals with obesity compared to those who remain obese without surgery [9]. Research indicates bariatric surgery can decrease overall cancer risk significantly, including colorectal cancer, by about 50% relative to obese individuals who do not have surgery [3][5].
Prof. Dr. Stefan Fichtner-Feigl, Medical Director of the Department of General and Visceral Surgery at the University Hospital Freiburg, stated that this research is an important step towards understanding and preventing colorectal cancer, especially in young patients [1]. The research team intends to explore further the impact of bile acid composition on colorectal cancer progression and potential therapeutic interventions.
In summary, for obese individuals, gastric bypass reduces colorectal cancer risk largely by addressing obesity-related factors known to promote carcinogenesis. Given obesity’s strong role as a colorectal cancer risk factor, weight loss surgery is considered beneficial from a cancer prevention perspective [3][4][5].
Science has revealed a potential link between gastric bypass surgery and the reduction of colorectal cancer risk, as well as prevention of metastases, in a study led by Dr. Rebecca Kesselring [1]. This surgery, often categorized under health-and-wellness and bariatric procedures, significantly reduces overall cancer risk, including colorectal cancer, by about 50% relative to obese individuals who do not have surgery [3][5].
