NAPA VALLEY, CA—Only 1 in 5 US patients with pancreatic cancer receive a widely available, inexpensive blood test at diagnosis that can predict whether they are likely to have a better or worse outcome than average and guide treatment accordingly. People who test positive for elevated levels of a particular tumor marker tend to do worse than others, but if they are candidates for surgery and have chemotherapy before their surgery, this personalized treatment sequence eliminates the elevated biomarker’s negative effect, researchers found.
The findings were presented at the Western Surgical Association 2015 Annual Meeting.
“This is another argument for giving chemotherapy before surgery in all pancreatic cancer patients and ending the old practice of surgery followed by chemo,” said senior author Mark Truty, MD, a gastrointestinal surgical oncologist at Mayo Clinic in Rochester, Minnesota. “The study answers an important clinical question and applies to every pancreatic cancer patient being considered for surgery.”
The Mayo study, which used the National Cancer Data Base, is the first on the subject based on national data and is the largest of its kind, Truty said.
Researchers analyzed outcomes for 97,000 patients. The tumor marker whose impact they studied is CA 19-9. It is associated with several cancers, including pancreatic cancer, and can be measured in the blood of most people; 10% of people do not produce it. Patients with pancreatic cancer who did not secrete CA 19-9 were also studied.
Patients with pancreatic cancer whose blood showed higher-than-normal CA 19-9 levels tended to have worse outcomes than others at the same stage of cancer, the study found. Surprisingly, the elevated tumor marker’s negative effect on survival was most pronounced in patients whose disease was diagnosed at an early stage, the researchers wrote.
“When we looked at how these patients did after surgical removal of their cancers, the only treatment sequence that completely eliminated the increased risk posed by CA 19-9 elevation was chemotherapy followed by surgical removal of the tumor,” Truty said.
Another key finding was that only 19% of pancreatic cancer patients nationally have their CA 19-9 checked at diagnosis, far fewer than anticipated, he said. The CA 19-9 blood test has been standard for pancreatic cancer patients at Mayo Clinic for years.
Failing to test for and address elevated CA 19-9 means that many patients with above-normal levels may undergo significant surgeries that may not be as beneficial long term as anticipated, Truty said.
An estimated 50,000 people develop pancreatic cancer each year in the United States. Historically, only approximately 7% of pancreatic cancer patients have lived at least 5 years after diagnosis. But advances such as the CA 19-9 test and advances in chemotherapy, radiation, and surgical techniques are improving survival odds for many patients, Truty said.
“Our conclusion is that every patient should have a CA 19-9 test at diagnosis. This is a simple, cheap, and widely available test that allows personalization of pancreatic cancer treatment,” Truty said, noting that the test costs approximately $170, which is pennies on the dollar relative to the overall cost of a patient’s cancer care. “Further, patients with any elevation of CA 19-9 should be considered for preoperative chemotherapy to eliminate this risk.”