Weight Loss Reduces Breast Ca Risk in BRCA-Positive Women


A weight loss of at least 10 pounds will significantly decrease the risk of early-onset breast cancer in women who carry a BRCA mutation, according to results of a large case-control study.

Early-adulthood weight loss is especially important for women with the BRCA1 mutation. Among these women, the weight loss was associated with a 65% reduction in cancer risk, compared with a reference group of BRCA1 carriers, according to Joanne Kotsopoulos, a doctoral student at the University of Toronto, and her research colleagues (Breast Cancer Res. 2005;7:R833–43; doi 10.1186/bcr1293, online at

The investigators examined early-onset breast cancer in 1,073 matched case-control pairs; about 75% had BRCA1 mutations and 25% had BRCA2 mutations.

Weight loss of at least 10 pounds between age 18 and 30 resulted in an overall 34% reduction in the risk of breast cancer. The risk reduction was greater (63%) for breast cancers diagnosed between ages 30 and 40, but not significant for breast cancer diagnosed after 40 years of age.

Women who had the BRCA1 mutation experienced the greatest risk reduction with weight loss (65%). The risk reduction was nonsignificant (22%) for those patients with the BRCA2 mutation.

Weight gain of more than 10 pounds also canceled out any protective effect of parity.

Gaining more than 10 pounds and having two full-term pregnancies was found to increase the risk of a woman having early-onset breast cancer by 44%, compared with those who gained minimal weight and who had at least two pregnancies.

About 40% of the women who lost 10 pounds or more had a body mass index of 25 kg/m

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