The same Mayo Clinic research team that developed the Cologuard DNA-based stool test for colorectal cancer has also been working on similar technology for the early detection of pancreatic cancer. After encouraging early studies, they have now landed a patent for their methods.
Dr. David Ahlquist
, a Mayo Clinic medical professor and consultant in its division of gastroenterology and hepatology, led the team that, late in the last decade, developed the genomic science behind the Cologuard test, which Mayo licensed in 2009 to Exact Sciences Corp
. (NASDAQ: EXAS) of Madison, Wisconsin.
Now, in a patent dated November 29, Ahlquist and Mayo colleagues Dr. John Kisiel, William R. Taylor, Tracy Yab and Douglas Mahoney were also granted rights to their method of “Detecting Neoplasm,” through which bio-samples, such as those collected from stool, can be analyzed for pancreatic cancer-related DNA biomarkers.
In that regard, the method is similar to the science behind the Cologuard test, which has the ability to analyze genetic material “shedded” into waste from lesions in the colon and rectum and used to predict whether or not they are pre-cancerous.
After a lengthy approval process, the mail-in stool sampling kit is now being adopted by physicians nationwide as an alternative to invasive colonoscopies for routine screening purposes, and as a result more colorectal cancers—which can be successfully treated when found early—are being detected.
Dr. Ahlquist and Exact Sciences announced last year
they were working together to extend their collaboration, translating the success of Cologuard’s detection methods to other kinds of gastrointestinal cancers.
Like colorectal cancer, pancreatic cancer can be successfully treated if suspect cysts are discovered in a pre-cancerous stage. However, once the aggressive cancer has progressed even to the early stages, the prognosis is almost always dire.
Pancreatic cancer is the fourth-leading cause of cancer-related deaths in the U.S., claiming about 40,500 victims in 2015. In addition to having a dismal prognosis of less than five percent survivability when found too late, incidences of pancreatic cancer are also quickly rising: Some forecasts claim it will be the second-most fatal cancer in the U.S. by 2020.
Exact Sciences says it is especially vexing to battle because there has never been a practical way to routinely screen for pancreatic cancer. For example, pancreatic cysts and even primary tumors are often difficult to distinguish from surrounding material in magnetic resonance imaging and computerized tomography (CT) scans.
Ultrasound is often used to visualize the pancreas, but it usually isn’t accurate enough to detect malignant lesions under three centimeters in length. A specialized kind of ultrasound has emerged recently as a technique for pancreatic tissue diagnosis, but it isn’t very good at differentiating pancreatic cancer from mere chronic pancreatitis, leading to needless over-treatment.
Thus, the development of an accurate genetic test than can be routinely performed could have a profound effect on treating one of deadliest and fastest-growing forms of cancer. Exact Sciences asserts that “preliminary economic analysis data” suggests that by reducing over- and under-treatment, “this test could improve cost effectiveness, making it attractive to government and commercial payers.”
The company says early tests have been encouraging. Dr. Ahlquist’s lab has identified six specific DNA markers isolated from pancreatic juice. In a recently published study, co-inventor Dr. Kisiel reported using the approach on a small number of samples. His early results with one of the high-performing biomarkers showed 75-percent sensitivity and 95-percent specificity for the detection of pancreatic cancer in comparison to a normal pancreas and chronic pancreatitis.
However, Exact cautioned, those results will require validation through future clinical studies.
Meanwhile, Mayo has initiated a 300-patient clinical study to assess the sensitivity of these highly-discriminant biomarkers found in pancreatic juice for the detection of pancreatic cancer and high-grade dysplasia.