Their prediction is based on early lab tests on mice. No such vaccine exists for humans yet.
But results from mouse tests suggest the "exciting possibility" that embryonic stem cell vaccines might prevent cancer, write researcher John Eaton, PhD, and colleagues.
Their findings were presented yesterday in Prague, Czech Republic, at a joint symposium of the European Organisation for Research and Treatment of Cancer (EORTC), the National Cancer Institute (NCI), and the American Association for Cancer Research (AACR).
"At present, all I can say is that so far it looks good, and that, unless something unexpected happens, this strategy might someday be applied to humans at high risk for development of cancer," Eaton says in an EORTC news release.
Eaton is a professor of medicine and pharmacology/toxicology and the Brown Chair of Cancer Biology at the University of Louisville's medical school.
Eaton's team used embryonic stem cells taken from mouse embryos to make two experimental vaccines against mouse lung cancer.
One of the vaccines contained only embryonic stem cells. The other vaccine contained embryonic stem cells plus a growth factor to boost immune response.
The scientists split the test mice into three groups. One group of mice got the vaccine containing only stem cells. A second group got the vaccine containing both the stem cells and the growth factor. The third group got neither vaccine.
The mice were then exposed to chemicals that cause lung cancer.
All of the unvaccinated mice developed the disease.
But only 40% of the mice that got the stem cell vaccine and 10% of those that got the vaccine with both stem cells and growth factor developed lung tumors during the 27-week study.
No drop was seen in the number of adult bone marrow stem cells in the mice, according to the report.
SOURCES: EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics, Prague, Czech Republic, Nov. 7-10, 2006. News release, European Organisation for Research and Treatment of Cancer.
By Miranda Hitti
Reviewed by Louise Chang