High use of complementary and alternative medicine among a large cohort of women with a family history of breast cancer: the Sister Study.

Use of complementary and alternative medicine (CAM) is high among U.S. women, yet information is limited on use among women at increased breast cancer risk. We analyzed CAM use among women with a family history of breast cancer. CAM use was analyzed among women enrolled 2003-2009 in the Sister Study cohort. Eligible women were aged 35-74, U.S. or Puerto Rican residents, no personal history of breast cancer, and had ≥1 sister with breast cancer. Baseline data on CAM use in the past year were available for 49,734 women. Logistic regression models examined the association between CAM use and Gail Model breast cancer risk score. Results were compared to female participants in the 2007 National Health Interview Survey (n = 7965). Among Sister Study participants, there was high use of vitamin/mineral supplements (79 %), mind-body practices (41 %), manipulative/body-based practices (32 %), and botanicals (23 %). Overall use was higher than the U.S. female population. No association was observed between familial breast cancer risk and CAM use. Black women were more likely to use spirituality/meditation-based CAM modalities, while non-Hispanic white and Asian women were high users of dietary supplements. In a cohort of women with increased breast cancer risk due to family history, CAM use is higher than women in the general U.S. population and is associated with race/ethnicity. Use was not associated with breast cancer risk. Given the high prevalence of CAM use among women at risk for breast caner, research on the effectiveness of CAM use for disease prevention is needed.