THE DECISION TO ENTER A RANDOMIZED TRIAL OF TAMOXIFEN FOR THE PREVENTION OF BREAST-CANCER IN HEALTHY WOMEN - AN ANALYSIS OF THE TRADEOFFS

OBJECTIVE: Interest in breast cancer prevention has led to the Breast Cancer Prevention Trial (BCPT), a controversial randomized trial of ta moxifen for women at risk for breast cancer. The goal of our study was to determine whether the potential benefits of enrolling in the rando mized trial of prophylactic tamoxifen outweigh the potential risks. ME THODS: We used a decision analytic model based on the available data o n tamoxifen treatment benefits in women with breast cancer and extrapo lated to its use in healthy women. RESULTS: For a 50-year-old woman wi th a breast cancer risk twice that of the average woman her age, the B CPT offers an increase in life expectancy of about 9 days, a gain that is modest compared with other health interventions. For women ages 35 to 60 who meet the minimum risk of breast cancer for trial eligibilit y, the trial increases life expectancy by about 8 or 9 days. Assumptio ns about the effect of tamoxifen on the incidence of endometrial and l iver cancer and on quality of life associated with tamoxifen did not a lter our findings. CONCLUSIONS: Advocates and opponents of the BCPT sh ould temper their concerns to reflect the modest absolute benefits and harms associated with the trial. Although women at increased risk for breast cancer should be aware of the likely overall benefit associate d with entry into the trial, for most women, entry into the BCPT is un likely to after substantially their length of life, in either a benefi cial or harmful manner.