Can a Vaccine Prevent Breast Cancer?
June 1st, 2010 Print
A vaccine to prevent breast cancer has shown overwhelmingly favorable results in animals, according to a new study.
CBS has a report on researchers who have found that a single vaccination with the antigen a-lactalbumin prevents breast cancer tumors from forming in mice, while inhibiting the growth of existing tumors.
Human trials are set to begin soon but while the researchers are optimistic, they warn it’s a big leap from results in animals to similar results in humans.
In the study, genetically cancer-prone mice were vaccinated — half with a vaccine containing the antigen and half with a vaccine that did not contain the antigen. None of the mice vaccinated with the antigen developed breast cancer, while all the other mice did.
The Food and Drug Administration has approved two cancer-prevention vaccines, one against cervical cancer and one against liver cancer. But those vaccines target viruses — the human papillomavirus (HPV) and the Hepatitis B virus (HBV) — not cancer formation itself.
Cancer presents a quandary that viruses don’t in terms of developing vaccines, experts point out. While viruses are recognized as foreign invaders by the immune system, cancer isn’t. Cancer is an over-development of the body’s own cells. Trying to vaccinate against such cell over-growth would effectively be vaccinating against the recipient’s own body, destroying healthy tissue.
The key, Tuohy said, is to find a target within the tumor that isn’t typically found in a healthy person. In the case of breast cancer, he and his team targeted a-lactalbumin, a protein found in the majority of breast cancers, but not in healthy women, except during lactation. Therefore, the vaccine can rev up a woman’s immune system to target a-lactalbumin, stopping tumor formation without damaging healthy breast tissue.
The strategy could be to vaccinate women over 40, when breast cancer risk begins to increase and pregnancy becomes less likely. (If a woman would become pregnant after being vaccinated, she would experience breast soreness and would likely have to choose not to breast feed.)
For younger women with a heightened risk of breast cancer, the vaccine may be an option to consider instead of prophylactic radical mastectomy, researcher say.
