By Emma Ross
Associated Press
July 19, 2002 12:00:00
LONDON - The number of children women have and the length of time they breast-feed them are the most important factors influencing their chance of developing breast cancer, even more important than genetic factors, major new research shows.
The landmark study, published this week in the Lancet medical journal, found that if women breast-fed their children six months longer, they could reduce their chance of breast cancer by 5 percent, even if they have a strong family history of the disease. Experts said the findings help explain the mysterious rise in breast cancer rates in the past century. The number of children women have and the amount of time they breast-feed have both declined in the past 100 years. In the study, Oxford University epidemiologists analyzed the results of 47 studies of 150,000 women worldwide. "The risks go down the more children you have. Even if they'd never breast-fed, the risk of breast cancer went down by 7 percent for every additional child," said Valerie Beral, the study's leader. Regardless of the number of children, the risk of breast cancer dropped by 4.3 percent per year of breast-feeding.