Purpose: The Breast Cancer Prevention Trial (BCPT) published results in 1998 showing that the use of tamoxifen in high-risk women reduced the incidence of invasive breast cancer by 49%. We examined the clinical impact of the BCPT to determine whether high-risk women informed of these results would use tamoxifen for chemoprophylaxis and to investigate the factors influencing this decision.
Methods: Of 345 women evaluated for a breast lump at a referral center, 89 were defined as high risk for but did not currently have cancer. These women were contacted about their elevated risk and informed that there exists a medication proved to reduce this risk. They were encouraged to discuss the issue with their family physician, to whom we sent copies of the 3 largest tamoxifen chemoprevention studies, including the BCPT. Follow-up was conducted by telephone to determine each woman's choice regarding tamoxifen use for chemoprevention and to ascertain her reasons for reaching this decision.
Results: Of the 89 high-risk women, 1 decided to take tamoxifen for breast cancer chemoprevention. Only 48 women discussed tamoxifen with their family physician; in 3 cases (3.4%) the family physician recommended that the patient start taking tamoxifen, in 8 cases (9.1%) the family physician made no recommendations, and in 37 cases (42%) the family physician advised against tamoxifen. The most frequently cited factors influencing the decision not to start tamoxifen were a fear of adverse events (46.8%), the family physician's recommendation (31.9%), and a perceived low breast cancer risk (34%).
Conclusion: Family physicians recommended prophylactic tamoxifen to few women and even fewer women chose to take it. The major barrier appears to be concern about potential adverse effects of tamoxifen.