This is a multi-institution double-blind placebo-controlled trial whose main objective is to determine if 6 months of letrozole (2.5 mg daily) can reduce proliferation as assessed by Ki-67 in high risk postmenopausal women on systemic hormone replacement therapy who have random periareolar fine needle aspiration (RPFNA) evidence of hyperplasia with atypia or borderline atypia, and a minimum Ki-67 of >1.5%.
The primary hypothesis is that proliferation and expression of other estrogen response genes will be favorably modulated by six months of letrozole relative to placebo without substantially increasing hot flashes or worsening overall quality of life.
Primary Outcome Measures:
- Assessment of proliferation rate (Ki-67 by immunocytochemistry) in benign breast epithelial cells acquired by random periareolar fine needle aspiration from women at high risk for the development of breast cancer. [ Time Frame: 6 Month ] [ Designated as safety issue: No ]
Secondary Outcome Measures:
- Assessment of change in morphology by nuclear morphometry and the semi-quantitative Masood score index and change in qRT-PCR assessed estrogen response genes. [ Time Frame: 6 Months, 12 Months ] [ Designated as safety issue: No ]
- Mammographic density and bioavialable estradiol and testosterone will be assessed as well. [ Time Frame: 6 Months, 12 Months ] [ Designated as safety issue: No ]
- Change in biomarkers associated with bone and cardiovascular health, adverse events, BCPT Symptom Check List, hot flash score, general fatigue inventory, the Fibromyalgia Impact Questionnaire. [ Time Frame: 6 Months, 12 Months ] [ Designated as safety issue: No ]
- 25-OH vitamin D levels will be assessed. [ Time Frame: Baseline and 6 month 2 ] [ Designated as safety issue: No ]
Estimated Enrollment: |
108 |
Study Start Date: |
October 2006 |
Estimated Study Completion Date: |
July 2011 |
Estimated Primary Completion Date: |
July 2011 (Final data collection date for primary outcome measure) |
1: Experimental
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Drug: Letrozole
Letrozole 2.5 mg tablet daily. Then optional open label letrozole for another 6 months.
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2: Placebo Comparator
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Drug: Placebo
Placebo tablet daily for 6 months then optional open label letrozole for 6 months.
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Subsequent to the 6 month RPFNA for assessment of biomarkers, toxicity and quality of life assessments, all women may receive optional open-label letrozole for an additional 6 months, followed by a third RPFNA and biomarker