Could Small Particles in the Blood Make Early Diagnosis of Pancreatic Cancer Possible?

According to research conducted at the University of Texas MD Anderson Cancer Center whose results were announced this week, detecting certain small proteins released into the blood by cancer cells could enable noninvasive cancer diagnosis (without the need to take a tissue sample (biopsy) from the body). Based on this study, we anticipate that pancreatic cancer could be diagnosed at a very early stage in the near future.

Cancer cells release small particles containing DNA, RNA, and proteins, called exosomes, into the blood. In this study, scientists isolated and observed the glypican-1 protein from pancreatic cancer patients and named these exosomes GPC1 + crExos. According to the results, glypican-positive exosomes were found in serum samples from 250 pancreatic cancer patients. This finding showed that patients with chronic pancreatitis could be substantially distinguished from patients with early- or late-stage cancer. Glypican levels in exosomes were also found to be very low in patients whose tumors had been surgically removed. This study used exosomes collected and isolated from healthy donors and patients with breast and pancreatic cancer. High levels of glypican-1-positive exosomes were observed in serum samples from both cancer types. According to the researchers, because isolated exosomes contain DNA, RNA, and proteins, they may be used not only as cancer biomarkers but also in genetic analyses. In addition, glypican 1-positive exosomes isolated from blood samples can be stored frozen for long periods and reused later for research.

This study determined that glypican-1-positive exosomes provided much more realistic results than the widely used CA 19-9 biomarker. Animal studies showed that glypican-1-positive exosomes were detected in pancreatic cancer mouse models even when no pancreatic disease was observed with imaging methods such as magnetic resonance imaging (MRI). Pancreatic cancer can be effectively treated surgically (pancreaticoduodenectomy or the Whipple procedure) if diagnosed at a very early stage. Because pancreatic cancer is usually detected late, surgery is possible in only 15 percent of patients.

This study was published in Nature, considered one of the world's most prestigious scientific journals, on 24 June 2015. For detailed information about the study, you can consult the article in the references section.

Keywords: pancreatic cancer, early diagnosis, noninvasive, exosome, glypican-1 protein, GPC1 + crExos, biomarker, CA 19-9.