Pregnancy Hormone May Prevent Breast Cancer
Animal studies suggest hCG can lower a woman's risk
TUESDAY, April 19, 2005 (HealthDay News) -- A pregnancy hormone that causes genetic changes in breast tissue may also help lower a woman's risk for breast cancer, animal studies suggest.
Research has shown that a full-term pregnancy by age 20 cuts woman's breast cancer risk in half, possibly by allowing breast cells to reach full maturity so they can better resist carcinogenic changes.
In their previous work, researchers at Fox Chase Cancer Center in Philadelphia found that a hormone in the placenta -- human chorionic gonadotropin, or hCG -- promotes the full maturation of breast cells.
"This lead us to postulate that this hormone might be useful for breast cancer prevention in women," research pathologist Dr. Irma H. Russo said in a prepared statement.
In this latest study, her team gave female rats without a history of pregnancy daily injections of hCG, and compared their cancer incidence to that of never-pregnant female rats who did not receive hCG.
"Our results show that hCG induces permanent genetic changes in the mammary gland that are related to its breast cancer prevention effect," Richard Wang, a postdoctoral associate in Russo's laboratory, said in a prepared statement.
A second study compared four groups of rats: a pregnant group; a virgin group treated with hCG; a virgin group treated with the ovarian steroid hormones estrogen and progesterone; and an untreated group. It found that both hCG and full-term pregnancy induce permanent genetic changes in breast tissue not seen with steroid hormone therapy.
Both studies were presented April 17 at the American Association for Cancer Research annual meeting in Anaheim, Calif.
The U.S. National Cancer Institute has more about breast cancer prevention.