It is difficult to diagnose pancreatic cancer early; tumors cannot be felt like they can in some other cancers because the pancreas is so deep inside the body.
The research team, including co-senior author Dr. Brian Wolpin, of the Dana-Farber Cancer Institute in Boston, MA, publish their findings in the journal Nature Medicine.
It is difficult to diagnose pancreatic cancer early. Tumors cannot be felt like they can in some other cancers because the pancreas is so deep inside the body. Furthermore, the disease usually does not cause any symptoms until it has already spread to other organs.
"Most people with pancreatic ductal adenocarcinoma (PDAC) - by far the most common form of pancreatic cancer - are diagnosed after the disease has reached an advanced stage, and many die within a year of diagnosis," says Dr. Wolpin. "Detecting the disease earlier in its development may improve our ability to treat it successfully."
Dr. Wolpin and colleagues wanted to see whether PDAC triggers changes in the way the body uses energy and nutrients, and whether these changes could be detected in the blood prior to disease diagnosis.
Increased levels of branched-chain amino acids may be early sign of pancreatic cancer
The team assessed previously collected blood samples from 1,500 people who were part of large health-monitoring studies.
They looked for more than 100 compounds made during the metabolic process, known as metabolites, before dividing the samples into two groups: those that were from participants who later developed pancreatic cancer and those that were from participants who did not develop the disease.
The researchers found that the participants who went on to develop pancreatic cancer had higher blood levels of branched-chain amino acids (BCAAs) - essential nutrients that the body extracts from proteins found in foods - compared with participants who did not develop pancreatic cancer.
These increased BCAA levels were found in patients 2-25 years before they were diagnosed with pancreatic cancer, the researchers say. But they note that patients with high levels of these amino acids several years prior to diagnosis were at highest risk.
Past studies from the team have shown that mice with pancreatic tumors also have increased levels of BCAAs. With that in mind, the researchers hypothesize that these latest findings indicate that early pancreatic tumors in humans increase BCAA levels.
Further investigation revealed that a breakdown in muscle tissue is responsible for the increase in amino acids, as the process releases more of them into the bloodstream. They say similar activity is seen in cancer cachexia - a muscle-wasting disease than can occur in the early stages of cancer.
They note that they were surprised to find that this muscle tissue breakdown happened much earlier in the disease process than previously thought, meaning their findings may improve understanding of how pancreatic tumors impact other areas of the body.
Commenting on their results, co-senior author Dr. Matthew Vander Heiden, of the Massachusetts Institute of Technology and Dana-Farber, says:
"This work has the potential to spur progress in detecting pancreatic tumors earlier and identifying new treatment strategies for those with the disease."
Medical News Today recently reported on a study published in the journal Nature Genetics, in which researchers identified new genetic risk markers for pancreatic cancer.