Cancer Vaccines Show Promise, Say Latest Studies

Experimental Vaccines Designed to Treat Existing Cancer

Several new studies indicate that vaccines designed to fight pancreatic and head and neck cancers may someday become a critical part of cancer treatment. Researchers presented their results Tuesday at the annual meeting of the American Association of Cancer Research in Los Angeles.

One research team unveiled their findings from a phase I trial of a pancreatic cancer vaccine. The team was led by Andrew Lepisto, a postdoctoral researcher at the University of Pittsburgh School of Medicine. 12 subjects with pancreatic cancer received a vaccine designed to boost the body's immune response after surgery.

"Patients who are eligible for surgery represent about 20 percent of all pancreatic cancer patients," Lepisto said. "The goal of the vaccine was to raise a strong immune response to prevent the cancer from coming back."

The results were impressive. "We found that if we did the surgery and followed up with the vaccine, we extended patient's lives from a 20 percent five-year survival rate to over 42 percent," he said. "There are five patients who are long-term survivors."

Another study was led by Sanjay K. Srivastava, an assistant professor of pharmacology at the University of Pittsburgh School of Medicine. Srivastava's team studied the effects of triphala, a combination of powdered fruits from three different plants, on pancreatic cancer cells in mice. The researchers found that triphala killed cancer cells in the mice.

"Our results demonstrate that triphala has strong anticancer properties given its ability to induce apoptosis [cell death] in pancreatic cancer cells without damaging normal pancreatic cells," Srivastava said in a prepared statement. "With follow-up studies, we hope to demonstrate its potential use as a novel agent for the prevention and treatment of pancreatic cancer."

A third study was conducted by another team from the University of Pittsburgh. The team created a vaccine which works through the immune system to affect p53, a protein which limits tumor growth. The researchers used the vaccine to create cells which then killed head and neck cancer cells.