The goal of this research study is to evaluate the efficacy and safety of low-dose exemestane versus low-dose tamoxifen in post-menopausal women at high risk for breast cancer.
The names of the study drugs involved in this study are:
* Exemestane (a type of steroidal aromatase inhibitor) * Tamoxifen (a type of selective estrogen receptor modulator)
Postmenopausal state is defined⁸ as no menses for 12 months without an alternative medical cause. A high follicle stimulating hormone (FSH) level in the postmenopausal range may be used to confirm a post-menopausal state in women not using hormonal contraception or hormonal replacement therapy.
Recent (within 12 months from date of consent form signature) histologic diagnosis of ER+ve (>5%) DCIS (patients with DCIS should have undergone breast-conserving therapy i.e. lumpectomy to remove the tumor with negative surgical margins followed by radiotherapy (see footnote 1 below)) diagnosis within 3 years of HRL (ADH, LCIS, ALH), or;
At least 3% breast cancer risk at 5 years (or 5% risk at 10yrs) per one of the following risk models: the Breast Cancer Surveillance Consortium risk calculator V3 or Tyrer-Cuzick model V8 or;
Known carriers of a germline pathogenic/likely pathogenetic variant in the following moderate penetrance genes (CHEK2 or ATM), or women with chest wall irradiation before age of 30 years
Pre/perimenopausal women: exemestane is only effective in post-menopausal women
History of DVT or PE: tamoxifen can increase tendency to blood clot
Endometrial cancer: full-dose tamoxifen is associated with increased risk of endometrial cancers
Macular disorders: tamoxifen is associated with retinal damage
Dana-Farber Cancer Institute
Lead sponsor
Breast Cancer Research Foundation
Collaborator