TPS1609 Background: Recent evidence suggests that black cohosh (Cimicifuga racemosa) may be a potential agent for breast cancer prevention. The active ingredients in black cohosh preparations appear to be triterpene glycosides. Recent preclinical data suggest several mechanisms by which triterpenes may prevent and treat breast cancer, including anti-proliferative, pro-apoptotic, anti-estrogenic, and anti-inflammatory effects. Epidemiologic data demonstrate a significant protective effect of black cohosh against the development of breast cancer in healthy women, and prolonged disease-free survival in breast cancer patients. There is also abundant evidence demonstrating the safety and tolerability of black cohosh in several clinical trials studying its use for treatment of hot flashes. We hypothesize that efficacy of black cohosh can be demonstrated in a pilot pre-operative window trial in a cohort of women with ductal carcinoma in situ (DCIS). Methods: In this trial, we treat women with a 2-5 week pre-operative course of commercial standardized isopropanolic black cohosh extract (20 mg orally twice per day). We aim to demonstrate a reduction in breast epithelial cell proliferation as measured by Ki-67 staining in regions of DCIS using traditional IHC staining and AQUA analysis. We also assess safety and tolerability of black cohosh through monitoring of patient adherence, liver function tests and serum hormone levels. 22 patients will be enrolled onto the trial. Sample size is based on power calculations for the specific study aim of determining the mean change in the levels of Ki67, using a targeted effect size. Assuming a 10% drop-out rate, a sample size of 20 patients will achieve 91% power to detect a 0.8 standard deviation of difference with a two-sided significance level at 0.05 using Wilcoxon signed-rank test. Eligible subjects are pre- and post-menopausal women ≥ 18 years of age newly diagnosed with DCIS histologically confirmed on breast core biopsy, prior to definitive excision. Women who have recently taken any agent known to affect Ki67 levels in the breast (e.g. hormone therapy) are excluded. Enrollment is currently ongoing with 10 of 22 patients accrued. Clinical trial registry number NCT01628536. Clinical trial information: NCT01628536.
Anastrozole versus tamoxifen in postmenopausal women with ductal carcinoma in situ undergoing lumpectomy plus radiotherapy (NSABP B-35): a randomised, double-blind, phase 3 clinical trial
