Pancreatic cancer is currently the fourth most common fatal cancer in the world, and unfortunately it often has a poor prognosis as well. In fact, it is diagnosed by doctors in only 14 percent of high-risk individuals under the age of 50. However, roughly 10 to 15 percent of all pancreatic cancers are hereditary, allowing scientists to find ways to identify biomarkers that indicate the possibility of malignant tumors.
A team of Hopkins researchers discovered that more than four out of 10 high-risk subjects for hereditary pancreatic cancer have small pancreatic lesions a long time before the first symptoms begin to manifest. More importantly, they determined that performing ultrasound via endoscopy has superior diagnosing capabilities when compared to magnetic resonance imaging (MRI) and computerized tomography (CT) scans in finding these lesions.
These biomarkers can help reduce the death rate of high-risk individuals, since the survival rate begins to drop significantly once the symptoms begin to appear. About 25 percent of those eligible for surgery survive at least five years, while the rest have a 5 percent chance of surviving five years. Tracking the lesions before the symptoms show can significantly increase the chances of high-risk individuals living much longer lives.
The study included 216 high-risk individuals, who had at least two close blood relatives with pancreatic cancer and had certain genetic biomarkers, such as BRCA2. These are two factors that increased the chance of inheriting the disease. Doctors at medical institutes — including Hopkins, Mayo Clinic, Dana Farber Cancer Institute, Anderson Cancer Center and the University of California, Los Angeles — performed either CT scans, MRI scans or ultrasound via endoscopy on participants to determine the best method for searching the lesions.
The CT scan gathers a series of X-rays taken at different angles to produce cross-sectional images of the soft tissues inside the body. Doctors often study slices of the scans to visualize the body from different angles. MRI utilizes radio waves and properties of nuclear magnetic resonance (NMR) to image the nuclei of atoms in the body. Typically, MRI provides a better contrast when imaging the brain, muscles, heart and cancers than CT scans do.
The endoscopic ultrasound, as the name suggests, involves sending ultrasound waves to obtain images of the inside of the body. During the procedure, the doctor inserts a thin, lighted tube into the sedated patient’s throat, into the small intestines. The ultrasonic patterns that bounce off the walls of the internal organs can be collected to identify tumors that cannot be detected by CT or MRI.
CT detected pancreatic abnormalities in 11 percent of subjects, MRI detected 33.3 percent and the ultrasound detected 42.6 percent. Marcia Irene Canto, a professor of gastroenterology and oncology at the Hopkins School of Medicine, suggests that one advantage ultrasound via endoscopy has over CT and MRI is that it can sample cells from lesions for further study.
Studies of cells from these lesions can potentially lead to the discovery of new biomarkers that would allow doctors to diagnose pancreatic cancer earlier and more accurately. Recently, another Hopkins research team has been developing biomarkers from pancreatic cyst fluid that appears to have signs that predict cancer.
