Vaccine for Pancreatic Cancer Studied
Experimental Vaccine Appears to Extend Lives; So Do Chemo and Radiation
Jan. 22, 2007 (Orlando) -- A novel vaccine that encourages the immune system to seek out and destroy tumor cells shows promise for treating pancreatic cancer.
In a new study, pancreatic cancer patients who were given the experimental vaccine lived an average of 27 months.
That may not sound like much, but pancreatic cancer is the fourth deadliest cancer, with most victims surviving only 18 or 19 months after diagnosis, says Charles A. Staley, MD, head of surgical oncology at Emory University in Atlanta.
“With pancreatic cancer, we’ve been failing for so long,” he tells WebMD. “Most advances are the results of baby steps like this.”
Staley, who was not involved with the work, moderated a news conference to discuss the findings at the 2007 Gastrointestinal Cancer Symposium being held here.
How the Vaccine Works
Unlike flu and many other vaccines, most cancer vaccines under development are not intended to be given to healthy people to prevent disease.
Rather, they help sick patients bolster their immune system to better fight the cancer.
In this case, the goal is to re-educate the immune system to recognize pancreatic cancer cells as foreign invaders that need to be attacked and annihilated, says researcher Daniel A. Laheru, MD, an assistant professor at the Johns Hopkins Kimmel Cancer Center.
Usually, pancreatic cancer cells fly under the radar of the immune system, evading the body’s surveillance mechanisms, he tells WebMD.
Educating Immune Cells
To overcome that obstacle, the injectable vaccine uses irradiated pancreatic cancer cells that can no longer grow but are genetically altered to lure the body's immune cells.
When the immune cells encounter the irradiated cancer cells, they go to war.
“The cancer cells, which weren’t previously recognized as foreign by immune cells, are now recognized as being foreign,” Laheru says.
The revved-up immune cells go on the offensive, not only wiping out the irradiated cancer cells that have been injected into the patient, but also patrolling the body and killing off active cancer cells in their path.