Study: Early Pregnancy May Produce Protein That Cuts Risk of Breast Cancer

Women who have an early pregnancy may have a reduced risk of developing breast cancer because of increased levels of a tumor suppressor protein called p53, according to researchers at Baylor College of Medicine in Houston, Texas.

The findings, published in the Proceedings of the National Academy of Sciences, were based on trials in rats and mice.

Prior research has shown that women who become pregnant at age 19 or younger appear to have a 40 to 50 percent decreased risk of developing breast cancer.

Investigators gave estrogen and progesterone to young female rats and mice, and found a notable increase in both the levels and nuclear accumulation of p53 compared with rodents that had never been pregnant.

When researchers later induced cancer in the animals, they found that the animals given the hormones seemed to be less at risk of developing breast cancer.

Researchers concluded that a short exposure to estrogen and progesterone early in life may lead to a chronic continuous higher level of p53.

They do not know whether the effect will be the same in humans, speculate that a short course of drug therapy might make young women more resistant to breast cancer.

Other Sources: Proceedings of the National Academy of Sciences