Tamoxifen reduces primary
breast cancer incidence, yet causes serious side effects. To date, few women with increased
breast cancer risk have elected to use
tamoxifen for
chemoprevention. The objective of the study was to determine women's knowledge of and attitudes toward
tamoxifen following exposure to a tailored decision aid (DA). A total of 632 women with a 5-year risk of
breast cancer > or = 1.66% (Mean = 2.56, range = 1.7-17.3) were recruited from two healthcare organizations. Participants viewed an online DA that informed them about their 5-year risk of
breast cancer and presented individually tailored content depicting the risks/benefits of
tamoxifen prophylaxis. Outcome measures included behavioral intentions (to seek additional information about
tamoxifen, to talk to a physician about
tamoxifen, and to take
tamoxifen); knowledge; and perceived risks and benefits of
tamoxifen. After viewing the DA, 29% of participants said they intended to seek more information or talk to their doctor about
tamoxifen, and only 6% believed they would take
tamoxifen. Knowledge was considerable, with 63% of women answering at least 5 of 6 knowledge questions correctly. Participants were concerned about the risks of
tamoxifen, and many believed that the benefits of
tamoxifen did not outweigh the risks. This study is the largest to date to test women's preferences for taking
tamoxifen and one of the largest to have tested the impact of a tailored DA. After viewing the DA, women demonstrated good understanding of
tamoxifen's risks and benefits, but most were not interested in taking
tamoxifen for
breast cancer chemoprevention.