The Basal subtype is typically triple-negative breast cancer (TNBC).

• A. True
• B. Not necessarily
• C. Usually yes
• D. False

Answer: (A)

This question hinges on the relationship between basal-like breast cancers and receptor status. Basal-like cancers are defined by a gene expression pattern that mirrors cells in the normal basal layer of the mammary ducts. In practice, these tumors most often lack the three receptors used to guide therapy—estrogen receptor, progesterone receptor, and HER2—so they are categorized as triple-negative breast cancer. Saying the basal subtype is typically triple-negative captures this strong overlap. There are rare exceptions where a basal-like tumor might express one of these receptors, or a triple-negative tumor might not display the basal gene-expression pattern. But for the purposes of this statement, the typical scenario is that basal-like equals TNBC.