A Glimmer of Hope Against Pancreatic Cancer
A new screening test promises to catch this deadly cancer much earlier than previous tests
The five-year survival rate for patients with metastatic pancreatic cancer is under two per cent. But if the cancer is caught before it spreads, overall survival improves considerably. The problem is figuring out how to spot it early.
"There hasn't been a very good screening test," Gordon says. Ideally, he explains, a test to screen for a disease will be relatively inexpensive, noninvasive, safe, and highly specific and sensitive, meaning the results can be trusted to be accurate.
A New Test for Pancreatic Cancer
Gordon recently collaborated with researchers at the University of Vermont to enroll 546 participants in a test of a screening protocol designed to catch pancreatic cancer early in people with an elevated risk of the disease. To be eligible, participants had to have either at least one close relative with pancreatic cancer or a genetic mutation that increases the risk of the disease.
The first step in the protocol is a blood test that looks at levels of an antigen called CA 19-9; high levels can be a sign of pancreatic cancer. This test fits many of the criteria identified by Gordon: it's not expensive or invasive and it is safe. However, a patient who tests negative for CA 19-9 could potentially still have pancreatic cancer and one who tests positive might not have it. "But it's probably the best serum marker we have," Gordon says, which is why the team used it.
Detecting Cancerous Growths
Participants with high levels of CA 19-9 then had endoscopic ultrasound (EUS) imaging. Gordon says EUS is an effective way to detect pancreatic cancer early in its development. But, he adds, it's expensive and invasive and must be done under general anesthesia.
Of the participants, 27 had elevated CA 19-9 levels. All but one of the 27 underwent EUS imaging (one declined). Potentially cancerous growths were spotted in five participants, and in one the growth turned out to be pancreatic cancer. That person had surgery to remove the tumor and was still alive without a recurrence at the end of the study, over three years after having surgery. Two other participants had noncancerous growths serious enough to warrant surgical removal. The patients who did not have surgery were monitored to see if the findings became cause for concern.
Helping the Cause
Gordon says the test isn't yet ready for widespread use. But he and his colleagues noted in the journal Gastrointestinal Endoscopy that detecting the one cancer cost about $41,000—which is comparable to mammography or colonoscopy.
It was easy to recruit patients for the study, he adds, because anyone who has had a family member with pancreatic cancer knows how devastating it can be. "Family members are pretty shook up about it," he says. "They wanted to do something to help the cause." That's a goal Gordon shares as well.
Article by Amos Esty, originally published in the Winter 2011 edition of Dartmouth Medicine
February 06, 2012
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