(RxWiki News) Imagine you've been diagnosed with an aggressive form of breast cancer, but instead of chemotherapy, you're given four shots. This Twilight Zone-sounding scenario is on the horizon.
A vaccine made in part from a patient's own cells has proven effective in annihilating early HER2-positive breast cancers in about one in five women.
And these vaccines may protect women against developing more aggressive types of breast cancer in the future.
"Ask your oncologist about personalized treatments."
Investigators at the Perelman School of Medicine at the University of Pennsylvania report that a 4-week course of "an anti-HER2 dendritic cell vaccine" resulted in "complete tumor eradication" in one-fifth of women with ductal carcinoma in situ (DCIS), an early breast cancer that has not invaded outside tissue.
“I think these data more than prove that vaccination works in situations where the target is right,” says study leader, Brian Czerniecki, M.D., Ph.D, surgical director of the Rena Rowan Breast Center at the University of Pennsylvania.
The study involved 27 women with HER2-positive DCIS. After collecting and isolating a particular type of white blood cell, vaccines were made using each woman's own cells.
The patients were given every-other-week shots, four times. Two weeks after completing the vaccines, they had surgery to remove any remaining cancer.
Comparing biopsy samples from before and after the vaccines were given, researchers "saw dramatic changes," including:
- Five women had no visible evidence of disease at the time of surgery, meaning their immune system had knocked out the tumor.
- HER2 levels were cut by 50 percent in 11 patients.
- Two women saw a lowering of HER2 levels by 20 percent.
The team also examined immune responses and found that 85 percent of the women had developed what the researchers call a complete immune response.
This response remained in effect for as long as 52 months, meaning the women had some protection again HER2-postive disease returning.
Doctors currently have no way of knowing which women with DCIS will develop more serious, invasive forms of breast cancer.
Side effects of the vaccine, which is not currently commercially available, were minimal.
“I think if we target several of the HER2 family members, we’ll drive the tumor to a place where it has nowhere to go,” said Dr. Czerniecki, who is also surgical director of the immunotherapy program for the Abramson Cancer Center. “Basically, we’ll push it over a cliff because those pathways are critical for tumor survival.”
"This is an interesting study of a potential new strategy for treating DCIS," Adam Brufsky, M.D., Ph.D., professor of medicine at the University of Pittsburgh School of Medicine, told dailyRx.
"It will be interesting if vaccination could reduce the long term incidence of local recurrence of DCIS in these patients," said Dr. Brufsky, who was not involved in this study.
Dr. Czerniecki says these findings likely apply to invasive breast cancer and other tumors in which HER2 plays a role, including melanoma, lung, brain and colon cancers.
This study was funded by a National Institutes of Health grant, the Harrington Foundation, Pennies-in-action.org, and the Mistler Foundation.