Scientists have yet another clue to the roots of pancreatic cancer -- carrying too much weight in your teens and early adulthood.   

Researchers in Ontario tracked more than 300 people who developed cancer of the pancreas, one ofthe deadliest cancers. They compared the body mass index (BMI) of those with pancreatic cancer with the BMI of more than 1,200 healthy adults. Researchers compared BMI at four stages of life:  adolescence, during their 20s and 30s, during their 40s and 50s, and over the age of 50.

They found a 50 per cent greater risk of pancreatic cancer among those who had been overweight or obese during their teen years, or their early 20s and 30s. The study was published this week in the journal Cancer Causes Control.

"There is an early life risk factor," says lead author Laura Anderson, a professor at McMaster University in Hamilton, Ont. "People who were more likely to have obesity and be overweight (in adolescence and their early 20s and 30s) were more likely to have pancreatic cancer later in life.”

There is no reliable screening method to find cancer of the pancreas in the early stages. Most cases are diagnosed when the cancer is advanced, with few if any effective treatments to stop the disease  Only about eight per cent of all patients are alive five years after diagnosis. Finding early ways to prevent the disease is important, said Anderson.

Scientists don't know the exact reason why higher body weight is linked to pancreatic cancer. Some think that weight gain is linked to chronic inflammation, insulin resistance, and altered intestinal microbiota that may boost the risk of cancer.

Other studies suggest that weight loss, especially after bariatric surgery, appears to reduce the risks of multiple cancers and could be a way of preventing pancreatic cancer.

Still, the Canadian study is yet another red flag atop the obesity epidemic.

"I think healthy weight over the life course is important," said Anderson.

Breakdown of participants’ weight over the study:

  • stable-normal weight (38.9 per cent),
  • progressively overweight (42.2 per cent)
  • persistent overweight (12.6 per cent),
  • progressive obesity (4.2 per cent),
  • persistent obesity (2.1 per cent).

Participants who were in the “persistent overweight” and “progressive obesity” categories were associated with a higher risk of pancreatic cancer, compared to those in the stable-normal weight group.

Pancreatic cancer has been in the headlines since Canadian Jeopardy host Alex Trebek has come forward about his diagnosis and treatment.