A 44-year-old woman with HER2-positive breast cancer after surgery would most likely receive which combination of therapies?

• A. Chemotherapy, radiation therapy, followed by tamoxifen
• B. Chemotherapy, radiation therapy followed by Arimidex
• C. Chemotherapy and radiation therapy
• D. Chemotherapy, Herceptin, and radiation therapy

Answer: (D)

The key idea is that HER2-positive breast cancer after surgery is treated with systemic chemotherapy plus targeted therapy against HER2, along with local control of the breast/chest area.

Her2 overexpression makes the cancer more aggressive, so adding trastuzumab (Herceptin) to chemotherapy improves survival and reduces recurrence. This targeted therapy specifically blocks the HER2 signaling that drives tumor growth. After surgery, adjuvant chemotherapy is standard to address micrometastatic disease, and radiation therapy is used to minimize local recurrence by treating the remaining breast or chest wall and regional lymph nodes.

Endocrine therapy (like tamoxifen or an aromatase inhibitor) is used only if the tumor is hormone receptor–positive; it would not replace the need for HER2-targeted therapy in a HER2-positive tumor. Therefore, the most comprehensive and appropriate combination is chemotherapy with trastuzumab along with radiation therapy.