On Cancer: Blood Test Could Predict Which Patients with Pancreatic Cancer May Benefit from Chemotherapy

Pancreatic cancer is one of the most difficult cancers to treat. Because the disease does not cause symptoms in its early stages, pancreatic cancer is usually diagnosed only after it has spread to other parts of the body.

Though progress against pancreatic cancer has been slow, new combinations of chemotherapy drugs have helped to slow the advancement of the disease and extend patients’ lives. However, as the number of effective treatments for pancreatic cancer increases, new challenges emerge as physicians are left guessing which combination of drugs will benefit an individual patient.

Research led by medical oncologist Kenneth H. Yu, presented on January 25 at the American Society of Clinical Oncology’s annual Gastrointestinal Cancers Symposium, suggests that a simple blood test may be able to predict which chemotherapy regimen will work for some patients with pancreatic cancer.

Predicting Sensitivity to Chemotherapy

Dr. Yu and colleagues observed patients who had received one of 12 different chemotherapy combinations as directed by their doctor. They used a new test developed by CellPath Therapeutics that analyzes specific genetic changes found in circulating tumor cells (CTCs) – cells that have broken away from a patient’s primary tumor and entered the bloodstream.

The results of the test predicted how effective a chemotherapy regimen would be. Blood samples for testing were taken before chemotherapy treatments started and again when the cancer progressed.

In this observational study, researchers found that patients on a chemotherapy regimen predicted by the test to be highly effective did not experience cancer progression until they were about seven and a half months into treatment. When the test predicted the chemotherapy would be less effective, patients had progression of their cancer in an average of less than four months.

They also found that when samples were tested later in the treatment process, the specific genetic changes found in patients’ CTCs had shifted, suggesting that this tool can be used throughout the course of therapy to predict when treatment should be altered.

A Step toward Personalized Medicine

Dr. Yu says that the research is encouraging because it “offers a new strategy to personalize cancer therapy. The ability to less invasively predict which patients will respond to treatment as well as provide a signal when treatment resistance occurs is extremely valuable.”

To learn more, read a HealthDay interview with Dr. Yu about these results.