American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the recommended treatment for postmenopausal patients with estrogen and progesterone receptor-positive ductal carcinoma in situ?

1. Tamoxifen

2. Letrozole

3. Anastrozole

4. Exemestane

The correct answer is: Anastrozole

In postmenopausal patients with estrogen and progesterone receptor-positive ductal carcinoma in situ (DCIS), the recommended treatment often involves the use of aromatase inhibitors, which lower estrogen levels in the body and are effective due to the hormone sensitivity of this type of cancer. Anastrozole, one of the aromatase inhibitors, is commonly used in this setting and has been shown to reduce the risk of recurrence in patients with early-stage hormone receptor-positive breast cancer. The choice of anastrozole specifically can be attributed to its established efficacy in clinical trials for breast cancer management and its favorable side effect profile compared to other hormonal therapies. This makes it a suitable first-line treatment for postmenopausal women with DCIS after surgery, especially when the tumor is hormone-receptor positive. Aromatase inhibitors like anastrozole are often preferred over tamoxifen in postmenopausal women because tamoxifen acts as a selective estrogen receptor modulator (SERM) and is less effective at reducing estrogen levels in this population compared to the complete blockade achieved by aromatase inhibitors. Thus, anastrozole aligns with current guidelines and the evolving understanding of hormonal treatment in postmenopausal women with estrogen and