American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What characterizes triple-negative breast cancer?

1. Positive ER and PR, negative Her2

2. BRCA positivity and hormone receptor negativity

3. High Ki67 and ER negativity

4. High Her2 expression and low proliferation

The correct answer is: BRCA positivity and hormone receptor negativity

Triple-negative breast cancer is characterized by a lack of expression of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor 2 (HER2). This profile leads to the term "triple-negative." While BRCA mutations are often associated with triple-negative breast cancer, it is important to focus on the defining features of the cancer type itself. The correct response highlights the association of BRCA positivity with hormone receptor negativity, which is a notable characteristic of a significant subset of triple-negative breast cancers. Patients with BRCA mutations, specifically BRCA1 mutations, are more likely to develop triple-negative breast cancer. This association is clinically important as it influences treatment decisions and risk reassessment for patients and their families. The other options detail various receptor expressions and proliferation indices that do not accurately define triple-negative breast cancer. Positive ER and PR with a negative HER2 status describes hormone receptor-positive breast cancer, while high Ki67 alone does not specifically indicate triple negativity. Furthermore, high HER2 expression would categorize a breast cancer as HER2-positive, which is the opposite of triple-negative.