Which of the following drugs is used in management of breast cancer if it is estrogen receptor positive –
**Core Concept**
Tamoxifen and other selective estrogen receptor modulators (SERMs) are used in the management of estrogen receptor-positive breast cancer. These drugs work by competitively binding to estrogen receptors on cancer cells, thereby inhibiting estrogen's proliferative effects.
**Why the Correct Answer is Right**
Tamoxifen is a first-line treatment for estrogen receptor-positive breast cancer. It acts by competitively binding to estrogen receptors on cancer cells, which prevents estrogen from binding and stimulating cell growth. This binding of tamoxifen to estrogen receptors also reduces the expression of genes that promote cell proliferation. Tamoxifen is particularly beneficial in postmenopausal women with estrogen receptor-positive breast cancer.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because there is no commonly used drug in the management of estrogen receptor-positive breast cancer that matches this description.
* **Option B:** This option is incorrect because aromatase inhibitors, such as anastrozole, are used in the management of estrogen receptor-positive breast cancer in postmenopausal women, but they are not the first-line treatment.
* **Option D:** This option is incorrect because trastuzumab is a monoclonal antibody used in the management of HER2-positive breast cancer, not estrogen receptor-positive breast cancer.
**Clinical Pearl / High-Yield Fact**
When considering treatment options for estrogen receptor-positive breast cancer, it is essential to determine the patient's menopausal status, as this affects the choice of endocrine therapy.
**Correct Answer:** C. Tamoxifen is used in the management of estrogen receptor-positive breast cancer.