(Ivanhoe Newswire) – According to a new study, women with a family
history of breast cancer were 59 percent less likely to develop breast cancer
themselves if they breastfed their children.
"This is good news for women with a family history of breast cancer," Alison
Stuebe, assistant professor of obstetrics and gynecology at the University of
North Carolina at Chapel Hill School of Medicine and lead author of the study
was quoted as saying. "Our results suggest a woman can lower her risk of cancer
simply by breastfeeding her children."
Among women with a mother or sister with breast cancer, researchers found that
those who had breastfed were more than 50 percent less likely to develop
premenopausal breast cancer than those who did not breastfeed. The authors did
not find a difference in risk among women with no family history of breast
cancer.
For women with a family history, the risk reduction with breastfeeding was
similar to taking an anti-estrogen drug such as Tamoxifen for five years. But
unlike Tamoxifen, Stuebe says, "Breastfeeding is good for mothers and for
babies."
Stuebe and colleagues reviewed data from a long-term study of more than 100,000
women from 14 states. Stuebe's study followed more than 60,000 women who
reported at least one pregnancy in 1997, when breastfeeding was assessed in
detail, and followed them through 2005 to determine how many developed invasive
breast cancer.
How long a woman breastfed seemed to be less important than whether or not she
had breastfed, Stuebe said. The reduction in risk was similar whether women
breastfed for a lifetime total of three months or for more than three years.
Also, there was no significant difference in risk for women who breastfed
exclusively versus those who breastfed while supplementing with other foods.
While the researchers are not sure why breastfeeding reduces risk of breast
cancer, they suspect that when women do not breastfeed, inflammation and
engorgement shortly after birth causes changes in breast tissue that may
increase risk for breast cancer. Breastfeeding followed by weaning may prevent
this inflammation.
"We did not find an association between breastfeeding and premenopausal breast
cancer among women without a family history of breast cancer," Stuebe says.
"This could be because there's something about genetically caused breast cancer
that's affected by breastfeeding, or it could be because rates of breast cancer
were so low in women without a family history that we couldn't see an
association in this data set."
Stuebe says the research underscores the public health impact of policies that
help mothers successfully breastfeed. In a recent CDC study, more than half of
women said they stopped breastfeeding earlier than they wanted to. "Mothers and
babies need supportive hospital policies, paid maternity leave, and workplace
accommodations so that they can meet their breastfeeding goals," Stuebe says.
"Public health begins with breastfeeding."
SOURCE: Archives of Internal Medicine, August 10, 2009
