Phase I Dose-Finding Trial of Letrozole in Postmenopausal Women at High Risk for Breast Cancer
I. The primary objective of this clinical trial is to compare the effect of lower and
intermittent doses of letrozole to standard letrozole therapy on estrogen suppression in
postmenopausal women at high risk for developing breast cancer.
I. Comparison of the effect of lower and intermittent doses of letrozole to standard therapy
on signs and symptoms of estrogen deficiency, including menopausal symptoms, serum lipid
profile, and serum marker of bone turnover.
II. Comparison of the effect of lower and intermittent doses of letrozole to standard
therapy on nuclear chromatin abnormality of breast epithelial cells collected by random
periareolar fine needle aspiration (RPFNA).
I. Determine the prevalence of breast cancer stem cells in the fine needle breast aspirates
and explore the potential intervention effect on the prevalence of breast cancer stem cells.
OUTLINE: Patients are randomized to 1 of 4 treatment arms.
ARM I: Patients receive 2.5 mg of letrozole orally (PO) thrice weekly for 6 months.
ARM II: Patients receive 1.0 mg of letrozole PO thrice weekly for 6 months.
ARM III: Patients receive 0.25 mg of letrozole PO thrice weekly for 6 months.
ARM IV: Patients receive 2.5 mg of letrozole PO once daily for 6 months.
After completion of study treatment, patients are followed up at week 30.
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment
Percentage of serum estradiol suppression in postmenopausal women at high risk for breast cancer
Three one-sided two-sample t-tests will be conducted on the ratios of the mean percentage of suppression simultaneously to test for non-inferiority. A multivariate t-distribution is used to derive the critical value and the power.
Up to week 30
University of Arizona Health Sciences Center
United States: Food and Drug Administration
|Mayo Clinic||Rochester, Minnesota 55905|
|University of Arizona Health Sciences Center||Tucson, Arizona 85724|