Design issues for a breast cancer chemoprevention trial.
A design to evaluate the efficacy of tamoxifen as a chemopreventive agent for breast cancer in healthy, high-risk women is proposed. Factors to be considered include basic incidence rates in the general population, definition of high risk, screening efforts, sample size, and compliance to protocol. Assuming a breast cancer incidence of 3/1,000/year in women 50-59 years old with a first degree relative with breast cancer, we estimate that approximately 16,000 subjects would need to be randomized into a tamoxifen-placebo controlled trial to detect a 50% reduction in incidence. This assumes a 5% (two-sided) significance level and 90% power. Such a trial would need to be multicentered and might cost $64 million over a 5-year period.
DeMets
D L
DL
University of Wisconsin Clinical Cancer Center, Madison 53706.
Newcomb
P A
PA
Carey
P
P
D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control; D003365:Costs and Cost Analysis; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D016032:Randomized Controlled Trials as Topic; D012107:Research Design / Q000592:standards*; D012109:Research Support as Topic / Q000191:economics; D012307:Risk Factors; D013629:Tamoxifen / Q000627:therapeutic use*
D013629:Tamoxifen