May 20, 2019
Early data on pancreatic cancer detection presented at Digestive Disease Week® 2019
SAN DIEGO, CA – May 20, 2019 – Early research using blood-based methylated DNA markers, identified through the longstanding collaboration between Exact Sciences and Mayo Clinic, demonstrates a potential to achieve 92% sensitivity and 92% specificity for detecting the most common type of pancreatic cancer. Researchers presented the findings at Digestive Disease Week (DDW) 2019, the largest international gathering of physicians, researchers and academics in the fields of gastroenterology, hepatology, endoscopy and gastrointestinal surgery.
“These pancreatic cancer data showcase the strength of our marker discovery collaboration with Mayo Clinic, a partnership that is fueling our product pipeline,” said Kevin Conroy, chairman and CEO of Exact Sciences. “We aim to identify a minimally-invasive marker for a disease that often goes undetected until it progresses to an advanced stage, when fewer treatment options exist.”
Pancreatic cancer is the third-leading cause of cancer-related deaths in the United States. According to the American Cancer Society, half of all pancreatic cancer patients are diagnosed in later stages when the five-year median survival rate is only 3%. No major guidelines recommend routine screening for average risk patients because the current detection options have not shown to lower a patient’s risk of death.
Lead author and Mayo Clinic gastroenterologist Shounak Majumder, M.D. presented results from the 340-sample, case-control study. A panel of methylated DNA markers in plasma in combination with CA 19-9, achieved a cross-validated sensitivity of 79% in Stage 1, 82% in Stage 2, 94% in Stage 3 and 99% in Stage 4 pancreatic ductal adenocarcinoma (PDAC) with 92% specificity (81-100%). This combination was significantly better than CA 19-9 alone. As Majumder writes in the abstract, “CA 19-9 is unreliable for early detection and may be normal in advanced disease.”
Statistical modeling was used to identify the best algorithm to predict disease status in this sample set. Subsequently, the panel was cross validated by randomly splitting the entire data set into training and testing sets. The fitted model from the training set was used to predict disease status in the test set over multiple iterations. This study used a small number of archival patient blood samples, which could lead to over-fitting to this particular sample set and cause subsequent sensitivity and specificity to decline in a larger, prospective population. A prospective validation study is currently underway at Mayo Clinic.
“Powered by more than a decade of work with Exact Sciences, Mayo Clinic researchers continue producing promising data, in this case on blood-based biomarkers for pancreatic cancer detection,” said Paul Limburg, MD, MPH, AGAF, Exact Sciences chief medical officer and Mayo Clinic gastroenterologist.1 “While further research must be completed, this serves as an early indicator of encouraging news in the fight against this deadly disease.”
The Exact Sciences and Mayo Clinic collaboration focuses on identifying biomarkers for 15 of the deadliest cancers. A poster showing Mayo Clinic researchers work on esophageal cancer will also be presented at DDW.