A team of researchers, led by surgeons at the Kimmel Cancer Center at Jefferson in Philadelphia, has found further evidence supporting the ability of a protein to predict how well a patient with advanced pancreatic cancer will do after surgery, chemotherapy and radiation.
The levels of the protein CA 19-9 in the blood can be used to determine the need for further therapy, they say.
Adam Berger, M.D., assistant professor of surgery at Jefferson Medical College of Thomas Jefferson University, and his co-workers examined CA 19-9 levels and the survival of 385 patients with advanced pancreatic cancer who were treated with surgery and subsequent chemotherapy and radiation. They found that those patients whose post-operative CA 19-9 level exceeded 180 U/ml did much worse than those with lower levels.
In fact, at least half of those whose CA 19-9 level was higher than 180 U/ml lived for approximately nine months, while half of those whose levels were 180 or below lived more than twice as long, about 21 months. After three years, about 30 percent of those with levels 180 or under were still alive, while virtually none of the patients with levels above 180 remained alive. He reports his team's findings June 23, 2007 at the semi-annual meeting of the Radiation Therapy Oncology Group (RTOG) in Philadelphia.
"We think that it is a very sensitive predictor of response to chemotherapy and radiation after surgery," says Dr. Berger.
The main goal of the multicenter trial was to compare pancreatic cancer surgery patients who received two different types of chemotherapy , 5FU or gemcitabine , along with radiation. It was designed to look at CA 19-9 levels and survival after surgery as a secondary goal. Patients submitted blood samples prior to chemotherapy, which were analyzed for CA 19-9. Overall, 385 patients had levels that could be analyzed.
According to Dr. Berger, a post-surgery CA 19-9 level of 180 or less translated to a 72 percent reduction in death in patients treated with additional chemotherapy and radiation for pancreatic cancer compared to those with levels above 180.
While CA 19-9 is a well established tumor marker for pancreatic cancer, he notes, "These results allow us to stratify individuals for other therapies. If a person is operated on and has potentially curative surgery, but four to six weeks after surgery has a CA 19-9 level above 180, he or she should probably have a different treatment than what was given in this trial. They should probably have prolonged chemotherapy and hold off a little longer on radiation."
While CA 19-9 is elevated in most patients with advanced pancreatic cancer, its use as a cancer marker is not foolproof. It may also be elevated in other cancers, conditions and diseases, such as colorectal cancer, lung cancer and pancreatitis, for example.
"The findings make a strong case for everyone to have CA 19-9 scores checked after surgery," he says. "These should be followed regularly." In addition, he notes, other researchers are studying whether the rate of change in CA 19-9 can predict survival. Future trials may involve examining the predictive value of lower CA 19-9 scores.