NEW YORK (Reuters Health) - According to the results of a case-control study, breast-feeding for a cumulative total of more than 12 months significantly reduces the risk of breast cancer in women who harbor BRCA1 mutations. The breastfeeding effects seem to be much greater for these women than for women in general population of women.
“This means that if the woman is identified to have a BRCA1 mutation, it is possible to modify her breast cancer risk without having to resort to surgery,” Dr. Steven A. Narod from the Centre for Research in Women’s Health in Toronto told Reuters Health.
The study population consisted of 965 women with breast cancer and an equal number of control women without breast or ovarian cancer. Among those with BRCA1 mutations (n=685), the mean total duration of breast-feeding was significantly shorter for case than for control subjects -- 6.0 vs 8.7 months, respectively (p < 0.001).
Women carrying BRCA1 mutations who breastfed for more than 1 year were significantly less likely to have breast cancer than women who never breast-fed, with an odds ratio of 0.55, they report in the July 21st issue of the Journal of the National Cancer Institute.
This finding indicates that, for BRCA1 mutation carriers, “breast-feeding for 1 year will cut the risk of breast cancer in half,” Dr. Narod told Reuters Health. “But the remaining risk is still high -- 40%", he added.
There was no association between breast cancer risk and breast-feeding in women with BRCA2 mutations (n=280). However, because the sample of women with BRCA2 mutations was small, the researchers say it is “premature to conclude that a modest reduced risk is not present in this subgroup as well.”
“We are making a lot of progress in identifying the means of reducing breast and ovarian cancer risk in BRCA1 mutation carriers,” Dr. Narod said. “And this means that it will become more acceptable to undergo genetic testing,” he added.
Source: J Natl Cancer Inst 2004;96:1094-1098. [ Google search on this article ]
MeSH Headings:Genes, BRCA1Copyright © 2002 Reuters Limited. All rights reserved. Republication or redistribution of Reuters content, including by framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in the content, or for any actions taken in reliance thereon. Reuters and the Reuters sphere logo are registered trademarks and trademarks of the Reuters group of companies around the world.
