Scientists at the University of British Columbia have discovered a link between a dreaded cancer and high insulin levels.
The causal relationship, demonstrated for the first time, may mean that scientists can develop strategies for earlier detection of pancreatic cancer and methods to prevent the disease.
A study by eight researchers from UBC's department of cellular and physiological sciences (Life Sciences Institute) that was published August 1 in Cell Metabolism found that by lowering insulin levels in mice predisposed to developing pancreatic cancer, they were able to prevent the disease from starting.
James Johnson, a UBC professor and senior coauthor of the paper, explained the importance of the findings in an August 4 university news release: "Pancreatic cancer can be tricky to detect and is too often diagnosed at a late stage, making it one of the deadliest cancers. The five-year-survival rate is less than five per cent, and incidences of the disease are increasing alongside obesity."
According to the Canadian Cancer Society (CCS), the pancreas is a gland located behind the stomach that is part of both the digestive and endocrine systems. It is made up of endocrine cells (which make the hormones insulin and glucagon and release them into the blood to control blood-sugar levels) and, mostly, exocrine cells (which make enzymes to help digest food).
The CCS estimates that In Canada in 2017, 5,500 people were diagnosed with the disease and 4,800 died from it. The American Institute for Cancer Research says that pancreatic cancer is the 12th most commonly occurring cancer for men (the odds of contracting the disease are slightly lower for women, depending on where in the world they live).
Almost all cases are diagnosed after 50 years of age.
In the UBC study, mice that were disposed to develop pancreatic cancer were crossed with mice that could not increase insulin levels. The new strain was fed food for a year that was known to both promote the cancer and increase insulin levels. Those mice did not develop the beginnings of pancreatic cancer.
“No matter whether you look at the entire pancreas, lesions or tumours, less insulin meant reduced beginnings of cancer in the pancreas,” Johnson said in the release.
The UBC bulletin also said of future relevance of the study data: "In addition to examining the relationship between insulin levels and other cancers, the scientists would like to investigate whether decreasing excess insulin produced by the body could positively influence later stages of pancreatic cancer. They plan to work with colleagues at BC Cancer on human clinical trials."