Recent research on the link between gastric bypass and colorectal cancer may also shed light on a new generation of weight-loss drugs that resemble the after-effects of these procedures. For the most part,weight loss surgeries are associated with a lower risk of many cancers.
This is partly attributed to the fact that obesity itself increases the likelihood of cancers. The exception to this is colon cancer, Medical Daily reports.
In their study, researchers from Mount Sinai Hospital in Toronto said “A large nationwide retrospective cohort study of 15,905 obese subjects treated with bariatric surgery revealed a significantly increased incidence of colorectal cancer, relative to obese control subjects,” They found that the incidence rate of colorectal cancer increased with time after gastric bypass was performed.
To determine the focus of the study, researchers started considering different bile acids and hormones in the gut. These substances are all crucial to digestion, but some of them also work as growth factor hormones, such as glucagon-like peptide-2 (GLP-2).
Glucagon-like peptide-1 (GLP-1) seems similar to GLP-2
Glucagon-like peptide-1 (GLP-1) seems similar to GLP-2, but its functions are less known. The researchers used a genetic mouse model to study what happens when levels of this hormone increased or were eliminated altogether.
The authors found that the incidence of intestinal tumors in mice increased with activity of GLP-1. Conversely, eliminating the hormone was associated with a decreased number of tumors.
Dr. Daniel Drucker, senior author and a professor at the University of Toronto, said “Our paper now raises the possibility that GLP-1 is an intestinal growth factor,”
These findings have implications for drugs that increase levels of GLP-1, GLP-2 and bile acids. Medical Daily reports that drugs are being developed to treat diabetes and other metabolic conditions by targeting the glucagon receptor, increasing these substances.
“No previous studies to date have linked long-term use of GLP-1-based drugs with increased rates of cancer,” said Dr. Drucker, who said more research is needed. “However, we think patients with a previous history, or increased risk, of colon cancer may not be ideally suited for these therapies.”