Cell mixture attacks pancreas tumors

Few diseases are as brutally efficient as pancreatic cancer. Despite surgery, chemotherapy, and radiation treatments, it typically kills a person within a year of detection.

Like other cancerous cells, pancreatic tumor cells seem disguised—going unnoticed by the body’s immune system as they wreak havoc. Scientists seeking to blow this cover have now devised a way to attack the tumor by revving up the immune system.

The procedure uses white blood cells from healthy people. The scientists mix these cells with the patient’s white blood cells in a laboratory dish, culture the combination for a day or two, and then inject it directly into the tumor. In response, the patient’s immune system swings into action to reject the foreign cells, and it simultaneously attacks the tumor.

In the March 15 Cancer, the first published results of this therapy for pancreatic cancer show that the technique appears safe and, in some patients, extends survival time.

Between 1995 and 1997, scientists at the University of California, Irvine selected eight patients in whom cancer of the pancreas had already spread beyond that organ and who chose not to have chemotherapy. The researchers used a needle guided by ultrasound imaging to deliver up to 9 billion cells to each patient’s tumor.

Five of the treated patients survived longer than the average for people receiving chemotherapy or radiation for this cancer. One of the patients is still alive more than 3 years after the treatment, says study coauthor Gale A. Granger, an immunologist at Irvine. Two patients survived for 20 months before dying. Two others died after a little more than 1 year.

“This is encouraging. It’s a step in the right direction,” says Mace L. Rothenberg, a medical oncologist at Vanderbilt University in Nashville. “It shows that a nonspecific [immune] approach can have some effect on pancreatic cancer.”

Ultrasound examinations at 4 and 6 months after treatment showed that tumors in two patients had shrunk by more than half, while a third person’s tumor had shrunk somewhat less. In the five others, the cancer either had stalled or continued to grow.

Autopsies, which were performed on two of the seven patients who died, showed various immune cells surrounding the tumors, a sign that immune proteins called cytokines had orchestrated an attack on the cancer. However, the team doesn’t know specifically which immune agents assailed the tumor.

Although several of the patients suffered side effects—which included liver dysfunction, fever, and nausea–standard treatments relieved these problems.

Pancreatic cancer is often discovered belatedly and can disrupt gastrointestinal function, two factors that worsen a patient’s prospects, says oncologist Elizabeth M. Jaffee of Johns Hopkins Medical Institutions in Baltimore.

In separate research on animals, Jaffee and her colleagues are injecting tumor cells that have been genetically modified to produce certain substances that attract immune attention to a tumor. In the end, she says, this approach and the one used by Granger and his colleagues may become parts of a combined therapy to uncloak cancerous cells.

The UC-Irvine scientists are now trying their method on more patients. The new study also includes patients getting only chemotherapy.