A team of researchers from both the Dana-Farber Cancer Institute and Massachusetts Institute of Technology (MA, USA) have discovered a new marker that could eventually lead to a test for earlier detection of pancreatic cancer. For this the team analyzed metabolites in 1500 blood samples that had been collected as part of a wider health-monitoring study.
Pancreatic cancer is difficult to diagnose early. Approximately 46,000 individuals in the US will be diagnosed with pancreatic cancer this year leading to almost 40,000 deaths. This is due in part to the fact that, unlike many cancers, abnormalities and lumps created by the tumors cannot be felt and the disease is often asymptomatic until it is at an advanced stage. As a result the disease often stays undetected until symptoms – often caused as a result of the cancer spreading to other organs – become apparent.
“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,” explained Brian Wolpin (Dana-Farber Cancer Institute) coauthor of the paper, which was published recently in Nature Medicine.
The team was investigating if any changes to the use of energy and nutrients in the body were triggered by PDAC, and subsequently whether these changes could be detected in the blood as a means of early diagnosis. This was achieved by analyzing 100 metabolites in the samples and then grouping those individuals that went on to develop the PDAC and those that did not for comparison. From this they found that individuals who developed pancreatic cancer had higher levels of branched-chain amino acids (BCAAs) in their blood. Increased BCAA levels occurred anywhere from 2–25 years before a patient was actually diagnosed with the disease.
The hypothesis that pancreatic tumors lead to elevated levels of BCAAs was further supported by data from previous studies carried out by the team in mice that also showed increased BCAA levels in those with pancreatic cancer.
Through further investigation they found that the increase in amino acids is a result of the breakdown of muscle tissue much like in cancer cachexia – a muscle-wasting disease that may occur in the early stages of cancer. Using this information they hope to better understand how pancreatic tumors affect the rest of the body.
“This work has the potential to spur progress in detecting pancreatic tumors earlier and identifying new treatment strategies for those with the disease” commented Matthew Vander Heiden of the Massachusetts Institute of Technology (Boston, MA).
Source: Researchers identify early sign of pancreatic cancer; Mayer JR, Wu C, Clish CB et al. Elevation of circulating branched-chain amino acids is an early event in human pancreatic adenocarcinoma development. Nat. Med. doi:10.1038/nm.3686 (2014) (in press)