Body changes on routine CT scans precede pancreatic cancer

Years before anyone is told they have pancreatic cancer, the body is already changing. At Mayo Clinic, a team led by former research fellow Aleksander Bogdanski tracked how the balance of muscle and fat shifted over time in people who later developed the disease. The change showed up on abdominal CT scans that had already been taken.

The stakes are high. Pancreatic cancer remains one of the deadliest cancers, largely because most patients are diagnosed after the disease has already spread. Current surveillance programs focus mainly on people with inherited genetic risk or strong family histories, yet most pancreatic cancers occur outside those high-risk groups. Early warning signs for the rest of the population are therefore scarce.

The researchers analyzed scans from 1,825 patients with pancreatic ductal adenocarcinoma (PDAC), the most common type of the disease, and 3,650 matched controls from Mayo Clinic sites in Arizona, Florida and Minnesota. An artificial intelligence–based tool measured skeletal muscle, subcutaneous fat (under the skin) and visceral fat (around the organs) over time. Compared with controls, patients who later developed cancer showed significantly steeper declines in both subcutaneous and visceral fat during the three years before diagnosis. Differences in muscle mass were most apparent in the final 12 months.

“Pancreatic cancer often develops silently, making early detection extremely challenging,” says Yan Bi, M.D., Ph.D., a gastroenterologist at Mayo Clinic and senior author of the study. The measures reached what the researchers describe as moderate discriminatory ability: they separate future patients from controls, but imperfectly, and the authors present them as additional information for risk assessment, not a replacement for existing methods. Michael Wallace, M.D., a Mayo Clinic gastroenterologist and corresponding author, says the changes are “detectable on routine CT scans and differ from the changes observed in similar patients without cancer.”

For people who already undergo routine CT scans, the practical gain would be a risk signal drawn from images that exist anyway, before the cancer is clinically detected. The next step is algorithms that combine body composition with other routinely collected clinical factors and imaging biomarkers to flag patients at increased risk. The sources give no date for that tool and no clinical validation, so for now this remains a research finding.