In the neoadjuvant setting for HER2-positive breast cancer, dual HER2 blockade with trastuzumab and pertuzumab is given. The NeoSphere trial showed that pathological complete response (pCR) rates were highest in which group?
- A Docetaxel + trastuzumab alone
- B Docetaxel + trastuzumab + pertuzumab ✓
- C Docetaxel + pertuzumab alone (no trastuzumab)
- D Pertuzumab + trastuzumab without chemotherapy
Correct answer: B. Docetaxel + trastuzumab + pertuzumab
Explanation
The NeoSphere trial demonstrated that adding pertuzumab to the docetaxel-trastuzumab backbone significantly increased pCR rates to approximately 46% compared to 29% with docetaxel-trastuzumab alone. Pertuzumab binds HER2 at domain II (blocking heterodimerization with HER3), complementary to trastuzumab binding at domain IV. Dual HER2 blockade plus taxane chemotherapy is now standard neoadjuvant therapy for HER2+ breast cancer. Achieving pCR is associated with improved event-free and overall survival.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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